Methods for monitoring CO2 emissions inadequate

Current methods for estimating greenhouse gas emissions have limitations that make it difficult to monitor CO₂ emissions and verify an international climate treaty, says a new National Research Council letter report to the administrator of NASA, Charles F. Bolden Jr.

NASA's Orbiting Carbon Observatory - which failed to launch in February -- would have offered proof that greenhouse gas emissions could be monitored from space, as well as provided baseline data on CO₂ emissions trends from a sample of cities and power plants, the report says. NASA is expected to decide in the coming months whether to launch a replacement observatory

The observatory was not designed for treaty monitoring and verification, and because of its two-year mission life, it would not by itself have been able to track emission trends. However, no other satellite has its crucial combination of high precision, small footprint, readiness, density of cloud-free measurements, and ability to sense carbon dioxide near the Earth's surface, said the committee that wrote the report.

Nukak 'face extinction'

Nukak preparing darts for their blowpipes. Photo: Gustavo Pollitis/SurvivalColombia’s national indigenous organisation, ONIC, has warned the United Nations that the Nukak, the country’s last hunter-gatherers, are in danger of extinction.

The warning was made in a report to the UN’s Special Rapporteur on Indigenous Peoples, James Anaya, who has recently visited Colombia. The Nukak are one of twenty-eight Colombian tribes considered by ONIC to face extinction.

ONIC’s report estimates the number of Nukak alive today to be 490, 40 percent of whom are living displaced from their traditional territories on the outskirts of a town called San Jose del Guaviare in Colombia’s south-east rainforest. In the twenty years since the Nukak’s first sustained contact with outsiders, half of the population has died.

‘The Nukak’s history demonstrates how indigenous people can very quickly see their numbers reduced and their culture eroded,’ says ONIC’s report.

Mr Anaya’s visit to Colombia was carried out between 23-27 July. ‘The situation of indigenous peoples’ rights in Colombia is serious, critical and deeply concerning,’ Mr Anaya said. ‘That was what the former Special Rapporteur on Indigenous Peoples, Rodolfo Stavenhagen, said after his visit to Colombia in 2004. The same can be said today, notwithstanding a number of important initiatives taken by Colombia’s government in the last few years.’

Family planning a major environmental impact

Some people who are serious about wanting to reduce their "carbon footprint" on the Earth have one choice available to them that may yield a large long-term benefit – have one less child.

A study by statisticians at Oregon State University concluded that in the United States, the carbon legacy and greenhouse gas impact of an extra child is almost 20 times more important than some of the other environmentally sensitive practices people might employ their entire lives – things like driving a high mileage car, recycling, or using energy-efficient appliances and light bulbs.

The research also makes it clear that potential carbon impacts vary dramatically across countries. The average long-term carbon impact of a child born in the U.S. – along with all of its descendants – is more than 160 times the impact of a child born in Bangladesh.

"In discussions about climate change, we tend to focus on the carbon emissions of an individual over his or her lifetime," said Paul Murtaugh, an OSU professor of statistics. "Those are important issues and it's essential that they should be considered. But an added challenge facing us is continuing population growth and increasing global consumption of resources."

In this debate, very little attention has been given to the overwhelming importance of reproductive choice, Murtaugh said. When an individual produces a child – and that child potentially produces more descendants in the future – the effect on the environment can be many times the impact produced by a person during their lifetime.

Under current conditions in the U.S., for instance, each child ultimately adds about 9,441 metric tons of carbon dioxide to the carbon legacy of an average parent – about 5.7 times the lifetime emissions for which, on average, a person is responsible.

And even though some developing nations have much higher populations and rates of population growth than the U.S., their overall impact on the global equation is often reduced by shorter life spans and less consumption. The long-term impact of a child born to a family in China is less than one fifth the impact of a child born in the U.S., the study found.

As the developing world increases both its population and consumption levels, this may change.

"China and India right now are steadily increasing their carbon emissions and industrial development, and other developing nations may also continue to increase as they seek higher standards of living," Murtaugh said.

The study examined several scenarios of changing emission rates, the most aggressive of which was an 85 percent reduction in global carbon emissions between now and 2100. But emissions in Africa, which includes 34 of the 50 least developed countries in the world, are already more than twice that level.

The researchers make it clear they are not advocating government controls or intervention on population issues, but say they simply want to make people aware of the environmental consequences of their reproductive choices.

"Many people are unaware of the power of exponential population growth," Murtaugh said. "Future growth amplifies the consequences of people's reproductive choices today, the same way that compound interest amplifies a bank balance."

Murtaugh noted that their calculations are relevant to other environmental impacts besides carbon emissions – for example, the consumption of fresh water, which many feel is already in short supply.

Iron isotopes as a tool in oceanography

New research involving scientists from the National Oceanography Centre, Southampton (NOCS) highlights the potential utility of iron isotopes for addressing important questions in ocean science. The findings are published in the August edition of the journal Geology.

Large regions of the world's oceans have low primary production despite having plenty of macronutrients such as phosphate, nitrate and silicate. This is due a shortage of the essential micro-nutrient iron, which is needed for the growth of phytoplankton. These tiny, plant-like organisms sit at the base of the marine food chain and collectively draw vast amounts of the greenhouse gas carbon dioxide down from the atmosphere through the process of photosynthesis.

A proportion of the carbon is exported to the deep ocean, making the oceans a major carbon dioxide sink, without which global warming would rapidly accelerate. The natural supply of iron to such 'High Nutrient Low Chlorophyll (HNLC) regions is therefore, albeit indirectly, an important determinant of climate.

The importance of dissolved iron in seawater derived from bottom (benthic) sediments is increasingly recognised as being important. Around the continental margins, in particular, iron is released from the sediments during the decomposition of organic carbon by dissimilatory iron-reducing bacteria - micro-organisms that use elemental iron to obtain energy. This leads to the enrichment of iron in pore fluids and bottom waters. However the ubiquity of sedimentary iron inputs to seawater remains unknown.

Different biological and chemical processes can leave behind characteristic isotopic 'fingerprints'. Of specific interest here, iron isotopes in sediment pore fluids may be a unique tracer of sediment respiration by dissimilatory iron-reducing bacteria.
Dissimilatory iron reduction is thought to be one of the earliest metabolic pathways on Earth , thus sedimentary iron isotopes may also be useful in reconstructing past iron cycling in the ancient ocean.

Pore-fluid iron isotope measurements have so far been restricted to the continental shelves where the supply of carbon is typically high and dissimilatory iron reduction is extensive, precluding comparisons with low-carbon, deep-water environments. William Homoky, who is a research student at the University of Southampton's School of Ocean and Earth Sciences based at NOCS, and his colleagues have helped fill this gap be measuring iron isotopes in pore fluids from both the Eel River shelf on the northern California margin (120 m water depth), and deep-sea sediments from the Southern Ocean around the Crozet Island Plateau (3000m water depth), about 1400 miles southeast of South Africa.

"We are excited by our findings not only because they represent the first measurements of their kind, but because they are telling us something important about iron cycling processes in the deep-sea, which can inform future iron isotope investigations in ancient rocks and the modern oceans," said William Homoky.

They find that the composition of iron isotopes in the pore fluids reflects the different extent of sedimentary iron recycling between the two sites. Specifically, the pore-fluid iron isotope compositions reflect the extent of iron recycling during early diagenesis, which is driven by organic carbon inputs from the overlying water column.

The researchers believe that iron isotope processing in carbon-limited environments, such as the deep-sea, is important and that it should help future interpretations of the rock record. "Additionally," they say, "the unique isotopic fingerprint of pore fluid iron in continental shelf settings is confirmed, highlighting the potential for iron isotopes to trace the inputs of continental shelf-derived iron in seawater."
Current thesis research aims to improve our understanding of iron cycling between sediments and seawater and compares the affects of contrasting sediment geochemistry on iron flux generating processes.

"In the future I would like to examine processes of sedimentary iron cycling in the high-latitudes, where sediments are subject to enhanced rates of environmental change due to changing climate in these regions," Said Homoky.

Opening a new window on daylight

Reducing electricity consumption by improving windows

A new approach to windows that could let in more light and cut indoor lighting needs by up to 99 percent in buildings in Tropical regions without losing the cooling effect of shades. Details are reported in the International Journal of Engineering Systems Modelling and Simulation this month.

Lerdlekha Tanachaikhan and colleagues in the School of Environment, Resources and Development, at the Asian Institute of Technology in Pathumtani, Thailand, explain that electric lighting is typically responsible for 25 to 40 percent of total electricity consumption in air-conditioned buildings. These figures could be reduced significantly they say if daylighting were used instead.

In Tropical regions, however, daylighting leads to a significant rise in temperature, which has to be countered by air-conditioning if the occupants are to remain cool and comfortable. This in turn consumes about 80percent of the total electricity consumption for the building.

Earlier studies on daylighting in buildings indicate that window designs and positioning are as diverse as buildings themselves and none currently provides a satisfactory answer to saving on the lighting bills without pumping up the air-conditioning.

The team has developed a formula for tropical sky climate conditions that allows them to assess different window configurations for daylighting. The formula takes into account glass type, solar and visible light transmittance and reflectance, shading coefficient and the heat insulation value, U.

The formula shows that for a city, such as Bangkok, the potential for daylighting is high and could cut daytime electric lighting requirements significantly. The team suggests that for more than 95percent of the occupancy period of a typical office building, daylight alone would suffice for lighting with the appropriate window configuration.

This saving would not be reduced significantly even with the use of vertical fins for east-facing windows and horizontal canopies for south-facing windows to reduce heating effects. Daylighting and shading effects can be optimized by following their formula and choosing appropriate windows size and positioning as well as other parameters, such as glazing transmittance.

Russia ready to host international tiger summit

Acting Minister of nature resources and environment of Russia Semyon Levi addressed World Bank Group President in a letter, saying Russia is ready to hold an international tiger forum in September or October 2010.

"The summit will help “to attract the attention of the world public to tiger conservation”, said Semyon Levi in the letter to World Bank.

“Russia is the only country where tiger population has considerably grown since mid 20th century”, said Igor Chestin, WWF-Russia CEO. “Holding the summit in Russia seems a reasonable idea”.

In June 2008, Robert Zoellick launched the Global Tiger Initiative, which made it mandatory on top-level officials to work out tiger conservation and restoration strategy at an international Tiger Summit in 2010. In April 2009, Igor Chestin sent a letter to Vladimir Putin, proposing to hold the summit in Vladivostok, a city in the Russian Far East. On May 4 Russian deputy prime minister Igor Shuvalov commissioned various ministries and agencies to work out a governmental decision on Chestin’s proposal.

Declining tiger population

Globally, tiger is one of the most threatened species on Earth. During the past 100 years, tiger population has declined by 25 times. And it is continuing to decline. In India, which has the biggest number of tigers, their population in 1995-2005 declined from 35,000 to 13,000. In some regions tigers have disappeared altogether, in South Caucasus, Central Asia, on Bali and Java. At present, tigers still inhabit 14 countries: Bangladesh, Butane, Vietnam, India, Indonesia, Cambodia, China, North Korea (unverified), Laos, Malaysia, Myanmar, Nepal, Russia, and Thailand.

Major threats to tiger include habitat loss, poaching, and human wildlife conflict in densely populated areas.

Russia is the only country in tiger habitat where species population has considerably increased since mid 20th century, and has remained stable during the past decade. The country today has the biggest tiger population in one signal range, over 450 tigers, or 11 per cent of the world population. This can be explained by conservation measures taken in 1950-1980s, including a complete ban on tiger hunting, creation of a net of protected nature areas, and scientific research.

Afghanistan prepares itself to resist deadly plant plague

Scientists are racing to arm Afghanistan against a new invader-a deadly, airborne wheat rust disease that threatens wheat production and food security in this war-torn nation and the region that stretches east across neighbouring Pakistan and into India.

Known as "Ug99", this deadly new virulent race of wheat stem rust has thus far been found in Kenya, Uganda, Ethiopia and Sudan, and has more recently spread into Asia, to Yemen and now Iran. "It is only a matter of time before it reaches Afghanistan and then South Asia," said Dr. Mahmoud Solh, Director General of the International Centre for Agricultural Research in the Dry Areas (ICARDA) in Aleppo, Syria. "We have been lucky so far, but we know that the disease is heading in this direction, and most of the varieties planted in the region are at risk. In fact, most of the wheat varieties used around the world are vulnerable to this stem rust; the last major outbreak of stem rust was seen during the 1950s."

The threat of Ug99 to the wheat fields of Afghanistan and other nations in the region has led wheat experts to agree that at least 10 percent of the nation's wheat fields must be replaced on an annual basis with Ug99-resistant varieties that are also adapted to conditions in Afghanistan.

"The stem rust threat is particularly dangerous because nearly all farmers in Afghanistan grow wheat for food or sale," said Dr. Mahmood Osmanzai, a wheat scientist from the International Centre for the Improvement of Maize and Wheat (CIMMYT), who is based in the country. "A wheat stem rust epidemic would be economically and culturally significant and far reaching."

Progress with support from donors

For the last six years, efforts to boost the production of disease-resistant varieties have been supported by funds from the Australian Centre for International Agricultural Research (ACIAR) and USAID, with significant progress. Scientists from ICARDA and CIMMYT have introduced seed of many high-yielding and disease resistant varieties of wheat. In addition to their success with multiplying resistant varieties, the scientists have preliminary results suggesting it may be possible to speed up seed multiplication by planting a second crop of wheat in high altitude regions where the climate is cooler. Thirteen farmers' associations, known collectively as the Afghan National Seed Organization (ANSAR), also have been created to grow seed of improved varieties for sale to other farmers. Yet challenges remain in meeting the demand for seed at an affordable price.

ICARDA scientist Dr. Javed Rizvi notes that farmers often lack credit to purchase the new seed. This means that the associations that produce the seed feel pressured to sell their stocks for food rather than waiting for farmers to pay the market price. "There are still too few places to store seed until the planting season in November," Rizvi said. "At this pace, it will be at least four years before enough seed of new wheat varieties becomes available, which is far too long, given the imminent danger of Ug99."

The country's agricultural research and extension capacity and infrastructure have been severely damaged after decades of war. ICARDA and CIMMYT are making efforts to help Afghan farmers get back on their feet by helping them improve and sustain crop production. These include the testing, evaluation, release and seed multiplication not only of wheat but of improved maize, chickpeas, mung beans, rice and potato varieties in collaboration with the International Rice Research Institute (IRRI) based in the Philippines, International Centre for Research in the Semi-Arid Tropics (ICRISAT) in India, the International Potato Centre (CIP) in Peru, and the World Vegetable Centre in Taiwan; promoting the use of high-value crops, like mint and saffron; and of conservation agriculture practices; as well as various efforts to train Afghan researchers/extension workers and farmers.

Osmanzai noted that six new promising wheat and three maize varieties have been released in Afghanistan in the last seven years, following an intensive process of testing, release and certification to ensure that they are suitable for local conditions. He says the emerging stem rust threat has added a new urgency to ongoing efforts to improve agriculture in the region.

"CIMMYT and ICARDA have been providing improved seed as well as training Afghan wheat scientists since the 1970s," Rizvi said. "To tackle Ug99, we would need to move faster than we ever have before, in order to address the threat and replace old varieties with new resistant ones."

Ensuring food security in Afghanistan and neighbouring countries is becoming increasingly difficult, according to the scientists responsible for improving agriculture in Afghanistan. A drought during the 2008 growing season severely reduced wheat harvests and caused grain shortages. And Afghanistan continues to face a potential "food deficit," although spring rains this year made possible a bumper harvest of 3.4 million tons of wheat, a jump of 127 percent over last year, according to the US Department of Agriculture.

"This year's harvest was good, but some of it was damaged by a second wheat disease known as yellow rust. This shrivelled the grain, so there could be unexpected deficits," Osmanzai said. "Afghanistan was self-sufficient in wheat in 1978, due in part to widespread adoption of varieties from CIMMYT. But production more recently has ranged from 2.3 to 4.5 million tons-far short of the yearly 5 million tons consumed."

New threat from old foe

According to Rizvi and Osmanzai, addressing wheat diseases such as stem rust and yellow rust is vital to any strategy to improve food security and agriculture in Afghanistan and of crucial importance in preventing the spread of Ug99 into Pakistan and India. Stem rust has plagued wheat farmers worldwide for thousands of years, but for the last 50 years it has been largely forgotten thanks to resistant varieties developed by a group of scientists led by Norman Borlaug, who earned a Nobel Peace Prize for his efforts.

Unfortunately, in 1998, the Ug99 stem rust variant discovered in Uganda showed itself able to overcome the resistance that was first established by Borlaug's team. Experts watched with alarm as Ug99 quickly moved to Kenya, where it proved capable of cutting wheat yields by 20 to 80 percent, with isolated incidents of total crop destruction.

Earlier this year, at the Borlaug Global Rust Initiative 2009 Technical Workshop in Mexico, researchers from CIMMYT, ICARDA, the Kenya Agricultural Research Institute (KARI), and the Ethiopian Institute for Agricultural Research (EIAR) described a technological breakthrough-the development of new varieties of wheat that are not only resistant to Ug99, but also produce more grain than today's most popular varieties. The scientists said their research suggests that 90 percent of wheat varieties planted around the world are vulnerable to Ug99, and that the pathogen is now in Kenya, Uganda, Ethiopia, Sudan, Yemen and Iran, and is on the march toward South Asia.

A global mapping system, modified from FAO models that track movement of locusts, is being put in place to follow and predict the pathway of Ug99, but Rizvi and his colleagues have launched their own simple early warning system using biological rust trap nurseries at three locations, including Herat near the Iranian border and Nangarhar near the Pakistani borders.

"So far the plants have been clean," Rizvi says, "but there's no telling how long before the new stem rust appears here."

Hope for world's troubled fisheries

Scientists have joined forces in a groundbreaking assessment of the status of marine fisheries and ecosystems.

Steps taken to curb overfishing are beginning to succeed in five of the 10 large marine ecosystems examined by scientists. The study provides new hope for rebuilding troubled fisheries.

The study reveals that the rate of fishing has been reduced in several regions around the world, resulting in some stock recovery. Moreover, it bolsters the case that sound management can contribute to the rebuilding of fisheries elsewhere.
It is good news for several regions in the US, Iceland and New Zealand.

Australian Beth Fulton, a fishery ecosystem scientist from the CSIRO Wealth from Oceans Flagship, was among an international team of 19 co-authors of the report on the two-year study, led by US scientists Dr Boris Worm of Dalhousie University and Dr Ray Hilborn of the University of Washington.

The study had two goals: to examine current trends in fish abundance and exploitation rates (the proportion of fish taken out of the sea) and to identify which tools managers have applied in their efforts to rebuild depleted fish stocks.

“These highly managed ecosystems are improving,” says Dr Hilborn. “Yet there is still a long way to go: of all fish stocks that we examined 63 per cent remained below target and still needed to be rebuilt.”

According to Worm, there is still a troubling trend of increasing stock collapse across all regions.

“But this paper shows that our oceans are not a lost cause,” Dr Worm says.
“The encouraging result is that the exploitation rate, the ultimate driver of depletion and collapse, is decreasing in half of the 10 systems we examined in detail. This means that management in those areas is setting the stage for ecological and economic recovery. It’s only a start but it gives me hope that we have the ability to bring overfishing under control.”

The authors caution that their analysis is mostly confined to intensively managed fisheries in developed countries, where scientific data on fish abundance is collected. They also point out that some excess fishing effort is simply displaced to countries with weaker laws and enforcement capacity.

Dr Fulton used the ecosystem models Atlantis and Ecosim to analyse ecosystem recovery in 31 fisheries worldwide, 10 in detail, including Australia’s Southern and Eastern Scalefish and Shark Fishery.

She says a combination of management measures has been adopted in Australia’s commonwealth fisheries in the past decade to reduce pressures on fishery ecosystems.
These intensive efforts involved cooperation between fishery scientists, managers and industry. Management measures included catch quotas coupled with strategically placed fishing closures, ocean zoning, selective fishing gear, community co-management and economic incentives (such as individual transferable quotas).

“Exploitation rates have more than halved since the early 1990s,” Dr Fulton says. “This means that management is setting the stage for ecological and economic recovery. As a result we are seeing recovery in overall ecosystem structure, even if some species aren’t fully recovered yet. But we can’t rest on our laurels.
Management methods need to be tailored to particular fisheries and regions and also need to change through time as the system changes.”

Fulton says surveys conducted up to the mid-1990s showed signs of recovery in
ecosystem structure in the North West Shelf region of Western Australia, although some species groups had not fully recovered.

Will a warmer lake doom invasive fish?

Jordan Read explains the mechanics of a water-mixing experiment as equipment is tested. The experiment, which involves a device that resembles a parachute with an inflatable ring, brings water from the bottom of a lake to the surface and raises the temperature of the deeper water. The experiment has implications for studying the effects of global warming as well as the effects of water temperature change on invasive species in lakes. Photos: Bryce Richter/University of Wisconsin-MadisonThe rainbow smelt, an invasive fish that threatens native species such as walleye and perch, may soon be feeling the heat, literally.

In an experiment that could show the way to evicting the unwanted fish from Wisconsin lakes, University of Wisconsin-Madison scientists and engineers hope to experimentally warm Crystal Lake in Vilas County in an effort to selectively wipe out the smelt. Using a device known as a GELI, an apparatus that looks like a submerged trampoline, the researchers will mix the waters of the 83-acre lake to warm the cool, deeper waters where the rainbow smelt thrive.

"As far as I know, this is a completely new idea," according to UW-Madison researcher Steve Carpenter, an authority on lakes and a leader of the new study along with civil and environmental engineering Professor Chin Wu.

"For it to work, one needs rather special circumstances," Carpenter explains. "The species you want to eliminate must be intolerant of warm water, and the warm water must not harm the native species that you wish to keep. That is the case in Crystal Lake and perhaps some other lakes in northern Wisconsin that have been invaded by smelt."

The idea, according to engineering graduate student Jordan Read, is to use the GELI -which is propelled up and down in the water column using compressed air and pushes water much like the bell of a jellyfish, to warm the deeper waters of the lake by a few degrees to a temperature the invasive fish is unable to tolerate.

"The main goal of the project is to mix the water column to the point where the deeper cold water habitat refuge for smelt is gone," says Read.

The experiment with a parachute-like device brings water from the bottom of a lake to the surface and raises the temperature of the water.Using the device, the Wisconsin researchers will warm Crystal Lake by about 6 degrees Fahrenheit, bringing the average July temperature of the lake to nearly 66 degrees Fahrenheit, a temperature intended to make things uncomfortable for the invasive fish.

The rainbow smelt is a native of the northeast coast of the US and was brought to the American Midwest in the 1920s as a potential food source for walleyes, one of Wisconsin's most prized game fish. But the smelt spread to lakes Michigan and Superior and is now finding its way to many of Wisconsin's smaller inland lakes.

Voracious predators

"Rainbow smelt are delicious, and many people know them as fried smelt," says Carpenter. "They are also voracious predators that gobble up juveniles of many fish species. They are particularly effective at eating walleye juveniles, and walleyes are often eliminated from inland lakes that are invaded by rainbow smelt."

The idea behind the Crystal Lake experiment, says Read, the graduate student directing the fieldwork, is to determine if artificially mixing the lake and warming its deeper waters will cause thermal stress for the smelt. The hypothesis, he explains, is that increased temperature will either kill the smelt outright or stress them to the point that survival and reproduction rates are greatly reduced. "The goal is to alter the thermal habitat the fish needs to survive," he notes of the experiment.

"Fish and most other aquatic invaders take on the temperature of their environment," says Carpenter, who explains that the rise in temperature should not harm native species such as walleye and bass. "If you warm the lake above the upper lethal temperature that the invaders will tolerate, they will die off."

The GELI is a radical departure from traditional methods of mixing lakes, says Read. Ordinarily, to alter the water temperature of a body of water the technique of choice is aeration, where compressed air is circulated through the water. The GELI technology could also potentially be used to restore oxygen to small areas of oxygen-depleted water.

"Preliminary measurements found the GELI technology to be much more efficient in comparison with traditional aeration techniques," says Read, of the 8-meter diameter membrane fitted with a hose-like collar which is alternately filled and emptied of air to raise and lower it in the water column. What's more, the GELI technology is more environmentally friendly as, unlike aeration, it does not stir up sediments.

'Vanishing species key in carbon trading'

The Association for Tropical Biology and Conservation (ATBC) and the Society for Tropical Ecology (GTOE) have jointly issued a “Marburg Declaration” that highlighted potentially serious weaknesses in current efforts to slow global warming and tropical deforestation.

Professor Nigel Stork, and Professor Steve Turton, professors at the University of Melbourne and James Cook University, respectively, are Councillors for the ATBC.
“If we’re going to limit harmful climate change, we simply must reduce the rampant destruction of tropical forests, which throws five billion tons of carbon dioxide into the atmosphere each year,” says Professor Turton.

“But it’s not enough just to reduce carbon emissions; we also have to save our most biodiverse forests and their imperiled species.”

The problem, say the scientists, is that international carbon traders will often focus on protecting disappearing forests where land is cheapest, such as in the Brazilian Amazon. Under agreements to be negotiated this December at the UN Climate Change Conference in Copenhagen, such carbon trading could soon amount to billions of dollars each year.

“Although it is important to save the Amazon, some of the most critically endangered species are not in Amazonia, they’re in the last surviving scraps of forest in places like the Philippines, Madagascar, West Africa, and the Andean Mountains of South America. These places are biodiversity hotspots, final refuges for thousands of endangered plants and animals,” says Stork.

“There’s enormous potential to help protect vanishing forests with carbon money, but if we’re not careful we could squander our chance to save critically endangered wildlife. We urge all nations and corporations to invest in carbon funds to help preserve disappearing forests.”

“But when you do so, pay a little extra so you’re protecting the most imperiled habitats. That way we can slow global warming and also save some of the most amazing and imperiled wildlife on earth.”

Emerson, Sun tie-up for energy-efficient datacenter

Emerson Network Power and Sun Microsystems Inc have announced a global sales alliance that will help provide businesses and organisations with roadmaps and technologies to increase the productivity and energy efficiency of their datacenters.

Globally, datacenter energy consumption is driven by businesses’ demand for greater computing capacity and increased IT centralisation. When combined with increasing global electricity prices, the financial implications are significant.

According to the Environmental Protection Agency, it is estimated that U.S. corporations and public agencies spent USD4.5 billion in 2006 to power their datacenters, and national datacenter energy consumption could nearly double in the next five years to more than USD7.4 billion annually, making datacenter efficiency a leading priority for customers. The power and cooling infrastructure that supports IT equipment in datacenters can account for more than 50 per cent of total data center energy consumption.

Sun's datacenter efficiency consultants will work directly with Emerson’s local Liebert power, cooling and services specialists throughout the world to assess, develop and maintain solutions to a variety of customer datacenter problems. The companies will deliver not only the plans but also the products and services for improved data center productivity and efficiency.

Dr. Robert W. Leland, director, Computing and Network Services Center at Sandia National Laboratories, said, “Right away, we recognised the great value of our association with Sun and Emerson Network Power, and we believe that our collaboration on a new and highly advanced HPC (High-Performance Computing) solution will provide leading-edge performance to our customers with substantially less environmental impact and much lower lifetime cost than the other options we had considered.”

Vanishing species key part of international carbon trading

Two leading scientific organisations today urged international carbon traders to help save some of the world’s most endangered forests and wildlife.

Meeting this week in Marburg, Germany, the Association for Tropical Biology and Conservation (ATBC) and the Society for Tropical Ecology (GTOE) jointly issued a “Marburg Declaration” that highlighted potentially serious weaknesses in current efforts to slow global warming and tropical deforestation.

Professor Nigel Stork, and Professor Steve Turton, Professors at the University of Melbourne and James Cook University, respectively, are Councillors for the ATBC.

“If we’re going to limit harmful climate change, we simply must reduce the rampant destruction of tropical forests, which throws five billion tons of carbon dioxide into the atmosphere each year,” says Professor Turton.

“But it’s not enough just to reduce carbon emissions—we also have to save our most biodiverse forests and their imperilled species.”

The problem, say the scientists, is that international carbon traders will often focus on protecting disappearing forests where land is cheapest, such as in the Brazilian Amazon. Under agreements to be negotiated this December at the United Nations Climate Change Conference in Copenhagen, Denmark, such carbon trading could soon amount to billions of dollars each year.

“Although it is important to save the Amazon, some of the most critically endangered species are not in Amazonia, they’re in the last surviving scraps of forest in places like the Philippines, Madagascar, West Africa, and the Andean Mountains of South America. These places are biodiversity hotspots—final refuges for thousands of endangered plants and animals,” says Professor Stork.

“There’s enormous potential to help protect vanishing forests with carbon money, but if we’re not careful we could squander our chance to save critically endangered wildlife. We urge all nations and corporations to invest in carbon funds to help preserve disappearing forests.”

“But when you do so, pay a little extra so you’re protecting the most imperilled habitats. That way we can slow global warming and also save some of the most amazing and imperilled wildlife on earth.”

Fund shortage affects aid flights

A WFP Humanitarian Air Service helicopter in flight from Kutum to El Fasher, North Darfur.
Photo: WFP/Emilia Casella
The humanitarian air service run by the UN World Food Programme (WFP) is struggling to keep its planes flying in parts of Africa due to a dramatic shortage of funds. The flights carry aid workers to remote locations where they provide vital assistance for hundreds of thousands of people – many of whom have been driven from their homes by conflict.

The UN Humanitarian Air Service (UNHAS), which is operated by WFP, carries aid workers to emergency operations where they provide support and assistance to populations affected by war and natural disasters. But the UNHAS air service to Chad will run out of funds by 15 August, while the UNHAS service in Liberia, Sierra Leone and Guinea will run out of funds by 30 August.

Reaching the hungry

“We fly thousands of aid workers to dangerous and remote locations all over the world. How will they reach people if they have no planes? How will WFP reach the hungry? How will doctors reach their patients? How will people have clean water if the engineers who help to build wells can’t get there,” asked Pierre Carrasse, Chief of WFP’s Aviation Branch.

In Chad, a monthly average of 4,000 humanitarian passengers fly on six UNHAS aircraft to reach 10 destinations, where they provide assistance to 250,000 Darfurian refugees and 180,000 internally displaced people in the East of the country.

Facing closure

The Chad service needs USD6.7 million to keep flying to the end of the year. If no new funds arrive by 15 August, UNHAS will be forced to start cutting back the number of aircraft and flights, and could eventually face closure. The West Africa Service, comprising Liberia, Sierra Leone and Guinea, needs just USD3.3 million to keep flying to the end of the year.

In February, UNHAS was forced to close its service in Ivory Coast due to lack of funds. The same month, the service to Niger was also cut, but thanks to a recent donation from the UN Common Emergency Relief Fund, the Niger service may resume in August.

UNHAS operates in Chad, Sudan, Somalia, Democratic Republic of Congo, Ethiopia, Central African Republic, West Africa and Afghanistan, with a 2009 budget of USUSD160 million. So far this year, the service has received less than USD40 million in contributions. It expects to raise a further USD50 million in fees to be paid by the organisations that use it.

Scientists refine, redefine seawater equation

UNESCO approves global team's tweaks to equation for improved climate projections

This summer, one of the world's leading ocean science bodies, the United Nations Educational, Scientific and Cultural Organization's (UNESCO's) and Intergovernmental Oceanographic Commission (IOC) adopted the new international thermodynamic equation of state for seawater called TEOS-10. A complex, dynamic mixture of dissolved minerals, salts, and organic material, seawater has historically presented difficulties in terms of determining its physical chemical properties.

For 30 years, climate models have relied on a series of equations called the International Equation of State of Seawater – or EOS-80, which uses the Practical Salinity Scale of seawater. This equation was used to determine the pressure, volume, temperature proprieties of seawater. Other thermodynamic properties, including heat capacity, enthalpy and sound speed were obtained using separate equations.

The Scientific Committee on Oceanic Research (SCOR) established a working group to look at the thermodynamic properties of seawater in 2005. The team included scientists from the Leibniz-Institut für Ostseeforschung in Warnemünde (Germany), University of Miami (USA), Desert Research Institute - Nevada System of Higher Education (USA), Bedford Institute of Oceanography (Canada), the Commonwealth Scientific and Research Organization (Australia), the National Oceanographic Centre (United Kingdom) and the Institute of Marine Geology and Chemistry (China).

This committee has established a fresh approach to seawater thermodynamics. The new equation of state is in the form of a comprehensive free energy function that includes all of the thermodynamic properties of seawater. The new thermodynamic equation of state will replace the widely-use EOS-80 with a new set of highly accurate and comprehensive formulas that provide necessary adjustments and clarifications to the original equation. Dr. Rainer Feistel, from the Leibniz-Institute, is widely recognized as the pioneer in developing the new free energy function.

"The previous International Equation of State of Seawater, which expresses the density of seawater as a function of Practical Salinity, temperature and pressure, served the oceanographic community well for three decades," said Dr. Frank Millero, professor of Marine and Atmospheric Chemistry at the University of Miami's Rosenstiel School of Marine and Atmospheric Science, who is the only member of the EOS-80 work group on the current team. "However, the new equation uses Absolute Salinity and is a compact 'one-stop-shop' of sorts that takes many variables that we hadn't previously included into account, and allows us to get at more precise numbers, which in turn, will make climate projections even more accurate."

Since the 1970's more than 14 graduate students, three undergrads, a high school student and four research technicians have worked on the pressure, volume, temperature and thermodynamic properties of seawater in Millero's lab at the University of Miami. These include Drs. Rana Fine and Arthur Chen, who have become important contributors to oceanographic science and education.

"Recently, our students and technicians have also been involved in examining the effect added salts in deep water have on the density of seawater in samples from all the major world oceans. The results of our investigations have been used to determine the Absolute Salinity of seawater, a variable needed as an input to the new equations," Millero added.

Big demo in India for clean energy

A thousand say NO to coal in Maharashtra

Close to a thousand villagers stood for hours in the formation of a life-size human windmill near Khidki village in Alibag, Maharastra demanding that the Maharashtra Government drop plans to build 10,000MW coal-fired thermal power plants in the region and explore renewable energy instead. The villagers said they were committed to fight the acquisition of their fertile land for coal-based power plants.

Over 1000 residents from villages in the Alibag taluka in Maharashtra took part in a giant human art formation of a windmill, to voice their opposition to coal-fired power plants planned in the region. Photo: Greenpeace“We believe that the energy planned from these coal plants is dirty. It can come instead from clean alternatives like wind and solar energy, and by using energy more efficiently. We will not give up our land and our future to these mega power plants that will pollute our air, land, and water. We will not allow them to ruin our children’s future by adding to the problem of climate change,” said Dr Vishnu P. Mhatre of the Naugaon Sangharsh Samiti, one of the organisations fighting for clean energy here.

The community is opposing plans to set up thermal power plants across over 8,500 acres of fertile land. The companies involved are the Tata Power Company Limited (1,200MW) and the Maharashtra Energy Generation Limited, a Reliance subsidiary, (4,000MW) at Shahpur in Alibag. The Patni group (500MW) and the Ispat group (2,000MW) want to set up their plants in the adjacent Medekhad Khadi.

For more than four years, the villagers have been resisting attempts by the government and the companies to acquire their land. “We do not oppose production of energy. But, we strongly demand that the India government change its energy pathway and move towards decentralised renewable energy, which will be used locally for agro-based industries and domestic needs,” said Satish Londhe, a resident of Alibag and state coordinator of the Shramik Mukti Dal.

To prove their solution-oriented approach, the citizens later joined in setting up a wind station. Admiral Ramdas, a Magsaysay awardee and a resident of Alibag, inaugurated the “Citizens’ Wind Monitoring Station” where the residents would record the area’s wind potential through an anemometer. This would show that the region has huge potential for wind energy, and challenge the government’s inaction in investing in alternate energies.

“Policymakers in the central and state governments need to explore the possibility of renewable resources like the wind, the sun, and other agents before rushing to coal for energy. In the current environment of global concern over climate change, we must also look critically at the operational efficiency of our power plants and increase energy efficiency in all sectors. This will ensure a dramatic reduction in our energy demand,” Ramdas asserted.

Maitree Dasgupta, climate campaigner with Greenpeace India, said: “This protest is a sign of popular opposition fomenting against coal in India, which will only grow. This is not a fight against growth or development. It is just the opposite. It is a fight for building energy infrastructure for the future instead of relying on dinosaur technologies. India can get 35 per cent of its power from renewable energy by 2030. We have the ability and technical capacity; we only need the political will.”

Greenpeace India is demanding that Prime Minister Manmohan Singh put in place a National Renewable Energy Bill no later than 2010, which would enable a shift towards a more sustainable energy pathway. This implies that the draft bill be made public this year for debate before placing it for parliamentary approval. It would also provide a framework for the Solar Mission and show that India is serious about the mission. More than 50,000 Indians have already signed Greenpeace India petitions demanding a response on this from Manmohan Singh.

Carbon labelling finds favour with Europeans

Photo: EurActivAn overwhelming majority of Europeans would like to see their purchases tagged with a label stating the total amount of greenhouse gases emitted during a product's lifetime, a new Eurobarometer survey found.

Seven out of ten citizens interviewed said a label indicating a product's carbon footprint should become mandatory in future. But only 10per cent identified total greenhouse gas emissions as the most important piece of product information that environment labels should display.

The survey revealed wide variations between different countries. A massive 90per cent of respondents in Greece and Croatia supported a mandatory EU scheme, while only around half of Czechs, Estonians and Dutch were in favour.

An EU-wide carbon footprint labelling scheme does not exist yet, but in December 2008, environment ministers requested the European Commission to investigate the possibility of introducing one. Currently, the Commission administers an ecolabel scheme, which has been rewarding environmentally friendly products with the Union's flower label since 1992.

But 61per cent of EU citizens interviewed said that they had never seen or heard of the label. Moreover, only a fifth acknowledged that they had bought products carrying the flower symbol.

The scheme is currently being revised to cover new products, including processed food. The Commission hopes that a single EU-wide ecolabel will reduce confusion among consumers triggered by mushrooming label schemes of recent years.

Nevertheless, Europeans take environmental concerns seriously, with eight out of ten Europeans claiming that they consider a product's impact on the environment important when deciding whether to purchase. But this does not necessarily translate into greener choices, as only a small minority considered environmental credentials to be more important than quality (7per cent) or price (19per cent).

Environment Commissioner Stavros Dimas pointed out that consumers play an important role in combating climate change. "By purchasing environmentally and climate-friendly products, individual customers send the right signal to producers who respond in turn by producing more eco-friendly products," he said.

The Commission seeks to boost demand for environmental products under its action plan on sustainable consumption and production, presented in July 2008. The plan includes initiatives such as the revision of the ecolabel scheme and new public procurement rules to favour the uptake of 'green' products (EurActiv 17/07/08).

Station ALOHA data reveal ocean acidification

The burning of fossil fuels has released tremendous amounts of the greenhouse gas carbon dioxide (CO2) into the atmosphere, significantly impacting global climate. Were it not for the absorption of CO2 by the oceans, the alarming growth of atmospheric CO2 concentration would be substantially greater than it is.

However, this beneficial role of the oceans as a CO2 “scrubber” does not come without undesired consequences. When dissolved, CO2 acts as an acid, and lowers seawater pH. Since the beginning of the industrial age, CO2-driven acidification of the surface oceans has already caused a 0.1 unit lowering of pH, and models suggest that another 0.3 pH unit drop by the year 2050 is likely.

Continued acidification of the sea may have a host of negative impacts on marine biota, and has the potential to alter the rates of ocean biogeochemical process.
Despite the global environmental importance of ocean acidification, there are few studies of sufficient duration, accuracy and sampling intensity to document the rate of change of ocean pH and shed light on the factors controlling its variability.

In 1988, Dave Karl and Roger Lukas of the School of Ocean, Earth Science and Technology (SOEST) at the University of Hawaii at Manoa founded the HOcean Time-series (HOT) program, in part to establish a long-term record of the oceanic response to rising atmospheric 2.

Monthly research cruises to Station ALOHA, north of Oahu, have yielded after 20 years the most detailed record to date on ocean acidification in the Pacific. Reporting in this week’s issue of Proceedings of the National Academy of Sciences, lead author and former SOEST researcher John Dore (now at Montana State University) presents an analysis of the changes of pH at Station ALOHA over time and depth.

Dore, along with SOEST co-authors Karl, Lukas, Matt Church and Dan Sadler, found that over the two decades of observation, the surface ocean grew more acidic at exactly the rate expected from chemical equilibration with the atmosphere.

However, that rate of change varied considerably on seasonal and inter-annual timescales, and even reversed for one period of nearly five years. The year-to-year changes appear to be driven by climate-induced changes in ocean mixing and attendant biological responses to mixing events.

The authors also found distinct layers at depth in which pH declines were actually faster than at the surface. Dore and colleagues attribute these strata of elevated acidification rates to increases in biological activity and to the intrusion at Station ALOHA of remotely formed water masses with different chemical histories.

China joins global water movement

With a growing water shortage and piloting new solutions to water stress, China is at the forefront of the world water quest. Home to 21 per cent of the global population, China has just 7 per cent of its freshwater. Moreover, the water is situated highly unevenly: some 80 per cent of the resource is found in the South of China where 55 per cent of the population lives, leaving the other 45 per cent of the population in the North often short of this vital resource. To connect to the global water community and enlarge its capacity to deal with the water challenge, the Chinese Government has agreed with the World Water Council upon a strong collaboration.

It was during an official visit to China that a delegation from the World Water Council met with representatives from the Chinese Government. “China is ready to increase cooperation with the World Water Council to jointly cope with water-resource challenges,” said Chinese Vice Premier, Hui Liangyu. “This agreement unfolds a new chapter of co-operation between the Ministry of Water Resources and the World Water Council”, added the Minister of Water Resources, Chen Lei.

With the aim to promote sustainable water management and improve access to water and sanitation, the agreement comes at a time at which China is more and more visible at the international level as demonstrated by its strong participation during the 5th World Water Forum in March 2009. “China is increasingly present in solving global water issues. It is the right moment to establish a more permanent presence of Chinese water expertise and know-how at the international level,” said Loïc Fauchon, President of the World Water Council.

The envisaged co-operation will focus on raising awareness on water issues within China and abroad. To this extent, the World Water Council also met the Vice Mayor of Shanghai to define how wise water use can be promoted during the upcoming Shanghai World Expo 2010, in strong collaboration with the Chinese Ministry of Water Resources. China finally expressed its will to be highly involved in the next World Water Forum that will be held in Marseilles, France, in March 2012.

Compass bans 69 vulnerable fish from restaurants

Contract caterer Compass Group has increased its ‘Fish to Avoid’ List in the UK and Ireland from 13 species to 69 based on an advise from Marine Conservation Society (MCS).

These species, including endangered Blue fin tuna, will not be served in any Compass Group UK and Ireland restaurants. MCS had identified species on Compass’ Fish to Avoid list as the “most vulnerable to over-fishing and/or are fished using methods which cause damage to the environment or non-target species” and include four varieties of skate, five tunas and two types of plaice.

The list offers details including the species, the methods of fishing and the geographical locations that are to be avoided. For example organically farmed Atlantic or Marine Stewardship Council-certified Pacific cod is fine to eat but Compass will not use wild Atlantic cod (caught from all areas except Northeast Arctic, Iceland and Western Channel, Bristol Channel and Southeast Ireland and Sole).

Compass created its Sustainable Seafood Guidelines, including its Fish to Avoid list, in October 2008. Blue fin tuna was included in the original list and in June 2009 swordfish was added, both in accordance with the MCS. The new list reflects the most up to date advice on the MCS website.

Neil Pitcairn, Fish and Seafood Buyer for Compass Group UK & Ireland, said, “Compass’ decision to follow the MCS’ guidelines and delist these species is significant. There are many wonderful and delicious fish that can be caught without risk of over-fishing.”

Simon Brockington, the MCS's Head of Conservation congratulated Compass Group UK & Ireland said, “By removing stocks from MCS' 'fish to avoid' list, Compass is helping to reduce demand for over-exploited fish. This is a crucial step in ensuring the long term survival of vulnerable fisheries.”

Ian El-Mokadem, MD, Compass Group UK & Ireland, said, “Compass has a clear commitment to sustainable sourcing, whether this be through providing full traceability of products and suppliers, or supporting British and Fairtrade farmers and growers.”

Restoration-based environmental markets may not improve ecosystem health

While policymakers across of the globe are relying on environmental restoration projects to fuel emerging market-based environmental programmes, an article in the July 31 edition of Science by two noted ecologists warns that these programs still lack the scientific certainty needed to ensure that restoration projects deliver the environmental improvements being marketed.

Markets identify the benefits humans derive from ecosystems, called ecosystem services, and associate them with economic values which can be bought, sold or traded. The scientists, Dr. Margaret Palmer and Dr. Solange Filoso of the University of Maryland Center for Environmental Science Chesapeake Biological Laboratory, raise concerns that there is insufficient scientific understanding of the restoration process, namely, how to alter a landscape or coastal habitat to achieve the environmental benefits that are marketed.

“Both locally and nationally, policymakers are considering market-based environmental restoration programmes where the science does not yet conclusively show that environment health will improve once the ‘restoration’ is completed,” said Dr. Palmer, who in addition to directing the UMCES Chesapeake Biological Laboratory is a professor of entomology at the University of Maryland College of Chemical and Life Sciences in College Park. “These programmes may very well make economic sense, but the jury is still out whether or not the local environment will ultimately benefit.”

At present, the demand in ecosystem service markets is driven by regulations that require those who harm the environment to mitigate or provide offsets for their environmental impacts. But in the regions throughout the world, including the Chesapeake Bay, many people hope that voluntary markets will expand outside of a regulatory context and result in a net gain of ecosystem services rather than just offsets for lost ecosystem services.

Examples include markets for flood protection created by restoring floodplains or wetlands and markets for improving water quality by restoring streams or rivers.
The scientists outline what should be done before markets expand further: recognise that restoration projects generally only restore a subset of the services that natural ecosystem provide, complete a limited number of projects in which direct measurements are made of the response of biophysical processes to restoration actions, and identify easily measured ecosystem features that have been shown to reflect the biophysical processes that support the desired ecosystem service.

“There is an inherent danger of marketing ecosystem services through ecological restoration without properly verifying if the restoration actions actually lead to the delivery of services,” said Dr. Filoso. “If this happens, these markets may unintentionally cause an increase in environmental degradation.”

The article, “Restoration of Ecosystem Services for Environmental Markets,” appears in the July 31 edition of Science. Their work is supported in part by a Collaborative Network for Sustainability grant from the U.S. Environmental Protection Agency.

The University of Maryland Center for Environmental Science is the University System of Maryland’s premier environmental research institution. UMCES researchers are helping improve our scientific understanding of Maryland, the region and the world through its three laboratories –Chesapeake Biological Laboratory in Solomons, Appalachian Laboratory in Frostburg, and Horn Point Laboratory in Cambridge – and the Maryland Sea Grant College.

Europeans care about environment: Survey

Four out of five Europeans say that they consider the environmental impact of the products they buy, reveals a Eurobarometer survey. Environmental consideration was highest in Greece where more than 9 in 10 of those surveyed said the impact of a product on the environment plays an important aspect in their purchasing decisions.

Europeans were evenly divided about claims by producers on the environmental performance of their products while nearly half thought that a combination of increased taxes on environmentally-damaging products and decreased taxes on environmentally-friendly products would best promote eco-friendly products. There was also strong support for retailers to play a role in promoting environmentally-friendly products and for mandatory carbon labelling.

EU Environment Commissioner Stavros Dimas said: "By purchasing environmentally and climate-friendly products individual customers send the right signal to producers who respond in turn by producing more eco-friendly products."

An overwhelming majority of Europeans (83 per cent) said the impact of a product on the environment plays an important aspect in their purchasing decisions. With 92 per cent in favour Greeks were more likely to consider the environmental impact of the products they buy while the Czechs were the least likely (62 per cent).

Europeans surveyed were evenly divided about claims by producers about the environmental performance of their products with 49 per cent trusting the claims and 48 per cent not trusting such claims. The Dutch were more likely to trust these claims (78 per cent) while Bulgarians were the least likely (26 per cent).

Some 46 per cent of EU citizens also thought that the best way to promote environmentally-friendly products would be to increase taxes on environmentally-damaging products and decrease taxes on environmentally-friendly products. Britons were most in favour of such a double taxation system while the Maltese much less so (28 per cent) preferring instead reducing taxes on environmentally-friendly products only.

Those surveyed were strongly in favour of retailers promoting environmentally-friendly products. Approximately half of EU citizens (49 per cent) thought that they should increase the visibility of such products on their shelves or have a dedicated green corner in their store. A third (31 per cent) of Europeans said that the best way for retailers to promote green products is for them to provide better information to consumers.

Despite just under half of Europeans saying that ecolabels play an important role in their purchasing decisions and only 1 in 10 saying the total amount of greenhouse gas emissions created by a product should feature on environmental labels, some 72 per cent of EU citizens thought that a label indicating a product's carbon footprint should be mandatory in the future. Attitudes on the subject varied widely between Member States with the Czechs the least in favour of such labelling (47 per cent) and Greeks wholeheartedly behind the idea with 90 per cent in favour.

Restoring a natural root signal helps to fight a major corn pest

The Western corn rootworm (insert) is a devastating pest of maize roots. By emitting the volatile compound E-β-caryophyllene in response to rootworm feeding, maize plants naturally attract insect-killing nematodes. Using genetic transformation, the signal was restored in an American line and in field tests it was shown that this dramatically increased the protection that the plants received from the nematodes. Photo: Matthias Held and Sergio Rasmann, University of Neuchâtel, SwitzerlandField trials in the US show that enhancing the attractiveness of maize roots to insect-killing nematodes can effectively fend off Western corn rootworm.

A longstanding and fruitful collaboration between researchers at the Max Planck Institute for Chemical Ecology and the University of Neuchâtel in Switzerland, together with contributions from colleagues in Munich and the US, has produced another first: the successful manipulation of a crop plant to emit a signal that attracts beneficial organisms. Genetic transformation of maize plants resulted in the release of the naturally active substance (E)-beta-caryophyllene from their roots. The substance attracts nematodes that attack and kill larvae of the Western corn rootworm, a voracious root pest.

In field tests, the enhanced nematode attraction resulted in reduced root damage and considerably fewer surviving rootworms. Further fine-tuning of this natural defense strategy will allow for an environmentally friendly growing of maize with minimised use of synthetic insecticides. The project was carried out within the framework of the Swiss National Centre of Competence in Research (NCCR Plant Survival).

The Western corn rootworm (Diabrotica virgifera virgifera) is the most damaging maize pest in the US and is responsible for enormous financial losses. Current methods to control the rootworm pest include insecticides, crop rotation and transgenic Bt maize lines that are not yet approved in Europe. After first invading the Balkans, the pest has since 2007 also been found in southern Germany. The corn rootworm larvae feed on root hairs and bore themselves into the maize roots.

The results are devastating: The plants take up less water and nutrients, and with the root mass severely reduced the plants lodge and collapse. In areas in Germany where the corn rootworm is a potential threat, the Federal Office of Consumer Protection and Food Safety (BVL) establish safety zones and enacts the use of the insecticide chlothianidine. In spring 2008 this insecticide was directly applied on the seeds, but during sowing it was unintentionally emitted as dust from abraded seeds, contaminated flowers, and poisoned 330 million honey-bees.

“Instead of using insecticides, the use of natural enemies of the corn rootworm could be much more environmentally friendly,” says Jörg Degenhardt, who was recently appointed professor at the University of Halle. While working in the group of Jonathan Gershenzon at the Max Planck Institute for Chemical Ecology in Jena he had already contributed to a key discovery four years ago by Sergio Rasmann in the group of Ted Turlings at the University of Neuchâtel. They found that maize roots attacked by rootworm attract nematodes by releasing (E)-beta-caryophyllene (EβC). One striking finding was that, after decades of breeding, most North American maize varieties no longer emitted EβC and had lost the ability to attract protective nematodes.

Therefore the research group in Jena and Neuchâtel teamed up again in an attempt to restore the EβC signal in a variety that normally does not emit the substance. Jörg Degenhardt, with the help of Monika Frey at the Technical University of Munich, transformed a non-emitting maize line with a gene that encodes an EβC generating enzyme, resulting in continuous emissions of EβC. Next, the Turlings group in Neuchâtel sent Ivan Hiltpold to Missouri, where, under the guidance of Bruce Hibbard of the United States Department of Agriculture, the transformed plants were tested in the field.

“Our study showed that the re-established natural EβC signal greatly enhanced the effectiveness of nematodes in controlling Western corn rootworm”, Hiltpold reports. In rows with EβC-producing maize plants root damage was greatly reduced; 60% fewer Diabrotica beetles emerged as compared to rows with nontransformed maize plants. This control efficiency approaches that of conventional synthetic insecticides used to fight Diabrotica. Subsequent laboratory studies confirmed that transgenic plants attracted significantly more nematodes than the non-transformed equivalents.

“The use of this indirect defense is an attractive strategy to increase plant resistance against herbivores and to reduce the use of chemical pesticides,” Degenhardt says. “The transgenic corn plants used in these experiments have no commercial value and the experiments simply served a ‘proof of principle’ that the EβC emission helps to protect the plants against underground infestation.” The EβC trait is present in other, mainly European, corn varieties as well as in the maize ancestor species. The trait could be reintroduced into deficient plants by conventional breeding. On the other hand, generating EβC emitting maize varieties by means of gene technology may have advantages: it is faster and prevents the loss of other important traits.

In further experiments the researchers want to determine the most effective way the nematodes and their response to the EβC can be applied. Moreover, the diffusing properties of caryophyllene make it an ideal belowground signal that could also serve to protect other crop plants. A patent for this approach has been
filed. [JWK, TT]

Coral to be part of genome project

Photo: FishonlineOne of the corals that form the backbone of the Great Barrier Reef (GBR) is to become the first complex animal to have its genes fully explored in Australia.

Plans to sequence the entire genome of Acropora millepora, a branching coral whose “staghorn” shape and beautiful colours are familiar to millions of visitors to the GBR, marks a major milestone in Australian biotechnology: it will be the first animal genome to be fully sequenced and assembled in this country.

The mapping of the coral genome is a joint undertaking by the Australian Genome Research Facility (AGRF) and researchers in the ARC Centre of Excellence for Coral Reef Studies (CoECRS) based at James Cook University and the Australian National University. Experts from other Australian research institutions including The Walter and Eliza Hall Institute and The University of Queensland will also be actively involved in project design, assembly and annotation of the genome.

“It’s a genuine first for Australian science. For years we have been looking on while overseas countries explored the genetic potential of our iconic native species. Now at last we have a genome project that is 100 per cent Australian,” says Professor David Miller of CoECRS and JCU, who with Dr Eldon Ball at the ANU is co-leader of the project.

The staghorn coral may look like a simple animal, but its genome is surprisingly large and complex. In fact, David says, Acropora has around 20,000 genes – about the same number as man. Why such apparently simple animals as corals should require as many genes as humans is still unclear, but it was this coral which provided the first hints of the how genetically complex “simple” animals can be.

Comparing the new coral genome venture with the human genome project shows just how far and fast genetic technology has advanced. The human genome project cost over $US 2.7 billion and was a massive international collaboration, whereas with “next-generation” sequencing technology, the costs have dropped to a fraction of the price enabling genomic studies to be more generally accessible. The Australian research will be carried out using the latest technology developed by the biotech company Illumina which is both fast and cost effective.

“Acropora millepora, is already the best-characterised coral at the molecular level and has yielded important insights into the evolution of all animals,” David explains. “Corals are among the simplest animals and may reflect the ancestral animal condition and reveal important features of genome evolution.”

As to why a coral has been chosen as the first Australian animal to be gene mapped by Australian scientists, David Miller explains: “Corals have iconic significance for Australia. We have the best-preserved coral reef system in the world and the Great Barrier Reef is a cornerstone of a $6 billion a year tourist industry. As reefs elsewhere in the world decline, this value will grow if we can keep our reefs healthy and intact.”

“This gene mapping project has both practical and scientific significance. It will help us to understand how corals build reefs – and why they fail to do so when they are under stress.

“It will enable us to predict with much greater confidence how corals are likely to respond to changes in the oceans such as global warming, acidification, the spread of coral diseases and various forms of pollution.”

While they don’t much resemble us, corals lie deep on the ancestral tree of all animals and share many of our genes, David adds. The project is expected to provide significant insights into the mechanisms that underlie the evolution of life on earth, including of the branch leading to the higher animals and humans.

Borneo tribe fights rainforest destruction

A logger handles trees felled in the Penan's region.Photo: Andy Rain/Nick Rain/SurvivalDozens of Penan tribespeople armed with blowpipes and spears have erected blockades across the roads cut by logging companies deep into their forest in Borneo. The blockaders are calling for an end to logging on their land.

Survival International is calling for recognition of the hunter-gatherer Penan tribe’s land rights and a halt to all development on their land without their consent.

Malaysian police are at the blockades, but no arrests have been reported.

One Penan man told Survival, ‘This piece of forest is the only place left for us to hunt and find food. But there’s only a little bit left. Last night I went hunting and came back with nothing. If we can’t save this bit of forest, we will have nothing to eat.’

The Penan live in Sarawak, in the Malaysian part of the island of Borneo. They have been struggling for more than twenty years to stop the companies clearing their forests. Some have been successful, but many have seen their forests devastated, their rivers polluted and the animals and plants they rely on for food disappear.

Now, where the valuable trees have all been taken, the companies are starting to clear the land completely for oil palm plantations. Palm oil is used in many foods and cosmetics, and increasingly for biofuels.

Survival sent action bulletins to thousands of supporters worldwide last week, asking them to write to the Malaysian government in support of the Penan.

Survival’s director Stephen Corry said today, ‘The logging and oil palm companies are robbing the Penan not just of their forests but of their food and water. It is essential that the Malaysian government recognizes the Penan’s rights to their land and stops allowing the companies to take everything in sight.’

The notorious Malaysian company Samling is logging in the Long Daloh area, and a subsidiary of the company KTS is logging in the Ba Marong area.

Europe food agency's junk science

Photo: Dan ShirleyAn opinion by Europe’s food agency advocating the safety of the only genetically modified (GM) crop grown in Europe is fundamentally flawed, according to a Friends of the Earth Europe and Greenpeace report.

The report will form the basis of a submission to a public consultation on Monsanto’s MON810 maize that ends this week. The green groups call on the European Commission and EU countries to reject the authorisation of this crop.

The ten-year licence for MON810 maize has expired and the EU is currently considering whether or not to re-authorise it.

It is in this context, the European Food Safety Authority (EFSA) issued an opinion at the end of June claiming that MON810 is safe. However, a scientific analysis of the opinion commissioned by Greenpeace and Friends of the Earth Europe has revealed serious mistakes and omissions by EFSA and questions its conclusion. Among other points, the report reveals that EFSA:

*ignores or plays down research that shows that the insecticide produced by the GM maize could have negative knock-on impacts on Europe’s butterflies and other insects. Instead they recommend unspecified “management measures” for areas known to host butterflies and moths;

*fails to admit that there is scientific uncertainty and conflicting reports over the maize’s impact on the environment or health;

*ignores peer-reviewed scientific studies that highlight safety concerns;

*quotes research carried out on a completely different GM crop as a basis for claiming that MON810 is safe;

*fails to investigate the safety of new unknown proteins generated in the maize by the genetic modification process.

“EFSA has once again violated its mandate. If university students submitted the EFSA report as course work, they would get the worst mark: an ‘F’. ‘F’ for failed but also ‘F’ for fundamentally flawed,” said Márta Vetier, Greenpeace EU GMO policy officer.

“The food safety agency either suffers from a serious lack of scientific expertise or is playing a highly risky political game with our health and environment. There is clearly enough evidence to show that this insecticide-producing crop could be hazardous and should be banned from Europe’s fields,” said Adrian Bebb, Friends of the Earth Europe’s Food and Biodiversity Coordinator.

Six countries have already banned the growing of MON810, including Germany and France. National governments have also been complaining about the quality of EFSA's work and have outlined their own concerns about the safety of the crop. Most recently, the French government stated that it could not accept EFSA's opinion on MON810. In May, twelve member states wrote to the Food Safety Authority expressing concerns about its ongoing work.

“The Commission has no other choice but to reject EFSA's opinion, ban the cultivation of MON810 maize and look for another official authority that is capable of delivering unbiased, science-based advice to decision makers”, added Márta Vetier.

Wind estimate ‘shortens Saturn’s day by five minutes’

Image: NASAA new way of detecting how fast large gaseous planets are rotating suggests Saturn’s day lasts 10 hours, 34 minutes and 13 seconds – over five minutes shorter than previous estimates that were based on the planet’s magnetic fields.

The research, published in this week’s Nature, was carried out by an international team led by scientists from Oxford University and the University of Louisville, USA.

Measuring the rotation of gas giants such as Saturn is difficult because the planet has no solid surface to use as a reference. Also, unlike Jupiter, Saturn’s magnetic fields are aligned with its rotation axis so that their fluctuations do not give an accurate measure of the rotation of the planet’s deep interior.

The new approach comes out of work begun over ten years ago by Timothy Dowling of the University of Louisville into measuring the movements of ammonia clouds across Saturn’s surface and the work of Professor Peter Read of Oxford University, who has been using data from the NASA Cassini spacecraft’s infrared spectrometer to study the planet’s atmosphere since 2004.

‘We realised that we could combine information on what was visible on the surface of Saturn with Cassini’s infrared data about the planet’s deep interior and build a three dimensional map of Saturn’s winds,’ said Professor Peter Read of Oxford University’s Department of Physics, an author of the paper. ‘With this map we were able to track how large waves and eddies develop in the atmosphere and from this come up with a new estimate for the underlying rotation of the planet.’

Professor Read said: ‘While shortening Saturn’s day by five minutes might not sound like much it implies that some of our previous estimates of wind speeds may be out by more than 160 miles per hour! It also means that the weather patterns on Saturn are much more like those we observe on Jupiter, suggesting that, despite their differences, these two giant planets have more in common than previously thought.’

The new finding could prove crucial in understanding the deep interior of the planet, whose rotation the team believes may be more complicated than a solid body because it is made up of fluid. It could also shed light on how Saturn and other gas giants – such as Jupiter, Uranus and Neptune – evolved.

Organic food has no nutritional superiority

There are no important differences in the nutrition content, or any additional health benefits of organic food when compared with conventionally produced food, an independent review commissioned by the Food Standards Agency (FSA) shows. The focus of the review was the nutritional content of foodstuffs.

Gill Fine, FSA director of Consumer Choice and Dietary Health, said: ‘Ensuring people have accurate information is absolutely essential in allowing us all to make informed choices about the food we eat. This study does not mean that people should not eat organic food.

What it shows is that there is little, if any, nutritional difference between organic and conventionally produced food and that there is no evidence of additional health benefits from eating organic food.

'The Agency supports consumer choice and is neither pro nor anti organic food. We recognise that there are many reasons why people choose to eat organic, such as animal welfare or environmental concerns. The Agency will continue to give consumers accurate information about their food based on the best available scientific evidence.’

The study, which took the form of a ‘systematic review of literature’, was carried out by the London School of Hygiene and Tropical Medicine (LSHTM). LSHTM’s team of researchers, led by Alan Dangour, reviewed all papers published over the past 50 years that related to the nutrient content and health differences between organic and conventional food. This systematic review is the most comprehensive study in this area that has been carried out to date.

The FSA commissioned this research as part of its commitment to giving consumers accurate information about their food, based on the most up-to-date science.

This research was split into two separate parts, one of which looked at differences in nutrient levels and their significance, while the other looked at the health benefits of eating organic food. A paper reporting the results of the review of nutritional differences has been peer-reviewed and published by the American Journal of Clinical Nutrition.

Dr Dangour, of the LSHTM’s Nutrition and Public Health Intervention Research Unit, and the principal author of the paper, said: ‘A small number of differences in nutrient content were found to exist between organically and conventionally produced crops and livestock, but these are unlikely to be of any public health relevance. Our review indicates that there is currently no evidence to support the selection of organically over conventionally produced foods on the basis of nutritional superiority.’

Rodent size linked to human population and climate change

You probably hadn't noticed - but the head shape and overall size of rodents has been changing over the past century. A University of Illinois at Chicago ecologist has tied these changes to human population density and climate change.

The finding is reported by Oliver Pergams, UIC research assistant professor of biological sciences, in the July 31 issue of PLoS One.

Pergams said that such size-and-shape changes in mammals, occurring around the world in less than a century, are quite substantial.

He had done earlier studies on a century's worth of anatomic changes between two geographically isolated rodents - Channel Island deer mice from coastal California and white-footed mice northwest of Chicago - and noted fast change among both.

"I suspected they weren't unique examples," he said. "I wondered whether these changes were occurring elsewhere, whether they were global in nature, and what some of the causes may be."

Pergams examined specimen rodents from museums around the world, including the big collections held at Chicago's Field Museum and the Smithsonian in Washington.

Altogether, he recorded more than 17,000 body and skull measurements from 1,300 specimens from 22 locations in Africa, the Americas and Asia. The animals were collected from 1892 to 2001, and Pergams compared those from before 1950 to those collected after.

He also compared specimens gathered from sparsely populated islands to those from the mainland, where human populations were denser.

Pergams found both increases and decreases in the 15 anatomic traits he measured, with changes as great as 50 percent over 80 years. Ten of the 15 traits were associated with changes in human population density, current temperature, or trends in temperature and precipitation.

"Rapid change, contrary to previous opinion, really seems to be happening quite frequently in a number of locations around the world," Pergams said. "There seem to be significant correlations with 'people-caused' parameters, such as population density and anthropologically-caused climate change."

While Pergams' study was by no means comprehensive, it was the first attempt of its kind to examine data on mammals from many global locations to find links between morphological change and variables such as population density and changing climate.

"Species can adapt quickly to rapid environmental changes - quicker than many people have thought, especially for mammals," said Pergams. "Those mammals that can adapt quickly have a much higher chance to survive big environmental changes caused by humans. Understanding which species and populations have the greatest ability to change has a crucial impact on being able to conserve biodiversity."

Concerns over green energy

The public is highly supportive of greener forms of energy, but has ‘legitimate’ concerns which Government and industry need to take more seriously if Government targets are to be met – according to a new study.

"The Government should put more emphasis on protecting the high levels of current public support for renewable energy, particularly for new offshore technologies and it is critical that this doesn't become eroded," said lead researcher Dr Patrick-Devine Wright from The University of Manchester.

"It is clear that the Government and Industry can do far more to keep the public onside and respond to the genuine reservations and concerns that some people have.”

“They should avoid the politically expedient term of Nimby," he added.

Professor Gordon Walker of Lancaster University said: "Just calling protestors 'Nimbies' and suggesting, as Ed Miliband recently did, that it should be socially unacceptable to oppose wind turbines, is just counterproductive.

"People have a democratic right to express their views, to scrutinise development proposals and to argue their case."

The researchers from six different Universities studied a range of different renewable energy projects - onshore and offshore wind, new tidal and wave technologies and biomass projects - across the UK.

Results of their survey work with local people showed little evidence of Nimbyism - only two per cent of the respondents to a survey of over 3,000 people fitted the stereotype of being strongly in favour of renewable energy in general, yet strongly against a local proposal.

The research also found no evidence to suggest that opponents of green energy were recent incomers to an area, older or living closest to the site.

Dr. Devine-Wright said: "Our results show that people generally support renewable energy, but that this support can be fragile, particularly for biomass and on-shore wind energy.”

“Offshore marine energy projects are so far being largely welcomed by nearby coastal communities, but large offshore wind farms can still sometimes be controversial.”

"We have identified what the key issues are that shape public concerns about new proposals. Developers and government should be acting to address these key issues, not labelling protestors as Nimbies.”

"They need to pay more attention to how the benefits or drawbacks of a proposal are perceived by local people.”

“By only focusing upon benefits at the global or national scale, they overlook crucial local aspects that shape public support.”

“Some developers are taking steps to bring more benefits to local people and this should become more widespread.”

"They also need to recognise the importance of reputation - certain technologies like wind turbines are almost expected to be controversial which colours local perceptions of specific projects. It can lead people to oppose the technology in any location, not just 'in their back yard.”

He added: "Developers must do more to ensure local residents feel they are being listened to. Providing information is simply not enough. This will then help to address a lack of trust, which can undermine their engagement with local residents.”

"And most importantly, Government needs to do much more to make sure that planning decision processes are open, fully informed and fair.”

"At the moment local people often feel disenfranchised as their concerns are not properly listened to or decisions end up being taken in a 'black hole' in London.”

"Under such conditions local resistance can easily escalate."

Household pesticides cause childhood cancer

Photo: Guillermo OssaResearchers caution that the study doesn’t prove cause and effect

A new study by researchers at the Lombardi Comprehensive Cancer Center at Georgetown finds a higher level of common household pesticides in the urine of children with acute lymphoblastic leukemia (ALL), a cancer that develops most commonly between three and seven years of age.

Researchers caution that these findings should not be seen as cause-and-effect, only that the study suggests an association between pesticide exposure and development of childhood ALL.

“In our study, we compared urine samples from children with ALL and their mothers with healthy children and their moms. We found elevated levels of common household pesticides more often in the mother-child pairs affected by cancer,” says the study’s lead investigator, Offie Soldin, PhD, an epidemiologist at Lombardi. Soldin cautions, “We shouldn’t assume that pesticides caused these cancers, but our findings certainly support the need for more robust research in this area.”

The study was conducted between January 2005 and January 2008 with volunteer participants from Lombardi and Children’s National Medical Center who live in the Washington metropolitan area. It included 41 pairs of children with ALL and their mothers (cases), and 41 pairs of healthy children and their mothers (controls). For comparison purposes, the case pairs were matched with control pairs by age, sex and county of residence. Previous studies in agricultural areas of the country have suggested a relationship between pesticides and childhood cancers, but researchers say this is the first study conducted in a large, metropolitan area.

Urine samples were collected from all child-mother pairs and analysed by the Centers for Disease Control and Prevention to look for evidence of organophosphates (OP), the chemical name of some household pesticides. The body breaks down OP into metabolites which can be tracked in urine samples. The researchers say pesticides were detected in the urine of more than half of the participants, but levels of two common OP metobolites, diethylthiophosphate (DETP) and diethyldithiophosphate (DEDTP), were higher in the children with ALL compared to the control children.

Also for the study, the mothers completed a questionnaire to collect information about the family’s exposure to pesticides, their medical history, home and neighborhood characteristics, diet, and history of smoke exposure. More case mothers (33 per cent) than controls (14 per cent) reported using insecticides in the home, however there was no correlation found between high levels of the OP metabolites in urine and reported use of pesticides.

“We know pesticides, sprays, strips, or ‘bombs,’ are found in at least 85 per cent of households, but obviously not all the children in these homes develop cancer. What this study suggests is an association between pesticide exposure and the development of childhood ALL, but this isn’t a cause-and-effect finding,” Soldin explains.

“Future research would help us understand the exact role of pesticides in the development of cancer. We hypothesise that pre-natal exposure coupled with genetic susceptibility or an additional environmental insult after birth could be to blame.”

Crashing comets not likely the cause of Earth's mass extinctions

A long-period comet called 2001 RX14 (Linear) turned up in images captured in 2002 by the Sloan Digital Sky Survey telescope in New Mexico. Photo: Mike Solontoi, University of WashingtonScientists have debated how many mass extinction events in Earth's history were triggered by a space body crashing into the planet's surface. Most agree that an asteroid collision 65 million years ago brought an end to the age of dinosaurs, but there is uncertainty about how many other extinctions might have resulted from asteroid or comet collisions with Earth.

In fact, astronomers know the inner solar system has been protected at least to some degree by Saturn and Jupiter, whose gravitational fields can eject comets into interstellar space or sometimes send them crashing into the giant planets. That point was reinforced last week (July 20) when a huge scar appeared on Jupiter's surface, likely evidence of a comet impact.

New University of Washington research indicates it is highly unlikely that comets have caused any mass extinction or have been responsible for more than one minor extinction event. The work also shows that many long-period comets that end up in Earth-crossing orbits likely originate from a region astronomers have long believed could not produce observable comets. A long-period comet takes from 200 years to tens of millions of years to make a single orbit of the sun.

"It was thought the long-period comets we see just tell us about the outer Oort Cloud, but they really give us a murky picture of the entire Oort Cloud," said Nathan Kaib, a University of Washington doctoral student in astronomy and lead author of a paper on the work being published July 30 in Science Express, the online edition of the journal Science. NASA and the National Science Foundation funded the work.

The Oort Cloud is a remnant of the nebula from which the solar system formed 4.5 billion years ago. It begins about 93 billion miles from the sun (1,000 times Earth's distance from the sun) and stretches to about three light years away (a light year is about 5.9 trillion miles). The Oort Cloud could contain billions of comets, most so small and distant as to never be observed.

There are about 3,200 known long-period comets. Among the best-remembered is Hale-Bopp, which was easily visible to the naked eye for much of 1996 and 1997 and was one of the brightest comets of the 20th century. By comparison, Halley's comet, which reappears about every 75 years, is perhaps the best-known comet, but it is a short-period comet, most of which are believed to originate in a different part of the solar system called the Kuiper Belt.

It has been believed that nearly all long-period comets that move inside Jupiter to Earth-crossing trajectories originated in the outer Oort Cloud. Their orbits can change when they are nudged by the gravity of a neighbouring star as it passes close to the solar system, and it was thought such encounters only affect very distant outer Oort Cloud bodies.

It also was believed that inner Oort Cloud bodies could reach Earth-crossing orbits only during the rare close passage of a star, which would cause a comet shower. But it turns out that even without a star encounter, long-period comets from the inner Oort Cloud can slip past the protective barrier posed by the presence of Jupiter and Saturn and travel a path that crosses Earth's orbit.

In the new research, Kaib and co-author Thomas Quinn, a UW astronomy professor and Kaib's doctoral adviser, used computer models to simulate the evolution of comet clouds in the solar system for 1.2 billion years. They found that even outside the periods of comet showers, the inner Oort Cloud was a major source of long-period comets that eventually cross Earth's path.

By assuming the inner Oort Cloud as the only source of long-period comets, they were able to estimate the highest possible number of comets in the inner Oort Cloud. The actual number is not known. But by using the maximum number possible, they determined that no more than two or three comets could have struck Earth during what is believed to be the most powerful comet shower of the last 500 million years.

"For the past 25 years, the inner Oort Cloud has been considered a mysterious, unobserved region of the solar system capable of providing bursts of bodies that occasionally wipe out life on Earth," Quinn said. "We have shown that comets already discovered can actually be used to estimate an upper limit on the number of bodies in this reservoir."

With three major impacts taking place nearly simultaneously, it had been proposed that the minor extinction event about 40 million years ago resulted from a comet shower. Kaib and Quinn's research implies that if that relatively minor extinction event was caused by a comet shower, then that was probably the most-intense comet shower since the fossil record began.

"That tells you that the most powerful comet showers caused minor extinctions and other showers should have been less severe, so comet showers are probably not likely causes of mass extinction events," Kaib said.

He noted that the work assumes the area surrounding the solar system has remained relatively unchanged for the last 500 million years, but it is unclear whether that is really the case. It is clear, though, that Earth has benefitted from having Jupiter and Saturn standing guard like giant catchers mitts, deflecting or absorbing comets that might otherwise strike Earth.

"We show that Jupiter and Saturn are not perfect and some of the comets from the inner Oort Cloud are able to leak through. But most don't," Kaib said.