Observations and computer models have long proven that the Arctic plays an important role in maintaining a stable climate on Earth. However, significant changes in the Arctic environment, especially those over the past decade, could lead to dramatic swings in weather and climate patterns across the rest of the globe, with potentially far-reaching consequences for ecosystems and human populations. Societies that have adapted to their current climates may be faced with highly disruptive changes over relatively short time periods.

Ground-based surface temperature data shows that the rate of warming in the Arctic from 1981 to 2001 is eight times larger than the rate of Arctic warming over the last 100 years. There have also been some remarkable seasonal changes. Arctic spring, summer, and autumn have each warmed, lengthening the seasons when sea ice melts from 10 to 17 days per decade.

Recently, a research study led by atmospheric scientist Jiping Liu of the Georgia Institute of Technology discovered that the total Arctic sea ice extent and area decreased, respectively, by 30,848 km2/year (11,910 square miles per year) and 35,372 km2/yr (13,660 square miles per year) using ice data between 1978 and 2002, derived from NASA’s Nimbus 7 satellite and several defense meteorological satellites. And, “if the current trends continue, Arctic sea ice will become much thinner in winter and almost non-existent in the summer, in keeping with increased greenhouse loading in the atmosphere,” said Liu. The paper, “Recent Arctic Sea Ice Variability: Connections to the Arctic Oscillation and the ENSO,” was published in the May 2004 issue of Geophysical Research Letters.

The Arctic is so important to the world’s climate because it acts as the “collection bed” for the world’s excess energy. In an attempt to balance energy across the Earth’s surface, heat is constantly being transported through atmospheric circulations and ocean currents from the equator to the poles, where it is ultimately released out to space.

But if the climate continues to warm faster in the Arctic than at lower latitudes, this transfer of heat will slow down, weakening overall atmospheric circulation. The weakening circulation would alter storm tracks, and their intensity, but the most profound impact would be on temperature. Oceans are capable of holding a tremendous amount of heat and moisture, which, when transferred through its surface to the atmosphere, can significantly alter temperature and pressure patterns.

Some scientists speculate that as low-latitude surface waters warm, forces like the El Nino-Southern Oscillation (ENSO) will strengthen and become even bigger players in the world’s climate.

El Nino (EN) is signaled by a warming of the ocean surface off the western coast of South America that occurs every 4 to 12 years when cold, nutrient-rich water does not come up from the ocean bottom. It causes die-offs of plankton and fish and affects Pacific jet stream winds, altering storm tracks and creating unusual weather patterns in various parts of the world. Southern Oscillation (SO) refers to a see-saw of high and low pressure that varies between Tahiti and Darwin, Australia.

Other researchers believe another cyclical atmospheric pressure system, called the Arctic Oscillation (AO) may also be responsible for declining Arctic sea ice. This oscillation refers to a pattern of low- and high-pressure systems between the Arctic and the mid-latitudes. When the oscillation is in its positive phase, as it has generally been over the last 20 years, air pressure tends to be low over the Arctic Ocean. Some scientists theorize that a general warming of the Earth could be pushing the oscillation toward a phase that warms the Arctic. The oscillation helps explain why summer sea ice is thinner than in years past. Since the 1980s, wind changes associated with the oscillation have pushed ice apart and shoved more ice from the Arctic into the Atlantic Ocean between Greenland and Norway.

Although Liu’s study showed that AO and ENSO trends cannot explain the recent regional sea ice trends, his research found they do influence the Arctic sea ice to some degree on time scales from year to year. “For example, with a positive phase of the AO, we usually observe more ice in the western Arctic and decreased ice coverage in the eastern Arctic,” said Liu. With strong El Nino events, however, there is more ice in both the eastern and western Arctic.

Liu also says that more study is needed to better understand how regional ice trends might respond to a warmer climate, including less understood large-scale processes such as the Pacific Decadal Oscillation (a long-lived, El Nino-like pattern of Pacific climate variability) and other influences, like river discharge into the Arctic Basin from Russia and Canada and glacier discharge from Greenland.

While melting Arctic sea ice will influence the atmospheric circulations in the high- and mid-latitudes, therefore altering the world’s weather patterns and storm tracks, it could also threaten the biodiversity of the Arctic Ocean.

A study led by Kevin Arrigo of Stanford University, “Annual Cycles of Sea Ice and Phytoplankton in Cape Bathurst Polynya, Southeastern Beaufort Sea, Canadian Arctic,” published in the April 2004 issue of Geophysical Research Letters, surveyed the impact of declining sea ice on marine ecosystems in the Canadian Arctic. Specifically, the research examined the association between annual sea ice cycles and biological productivity in the Cape Bathurst polynya. Polynyas are areas of open water or reduced ice cover, usually created by strong winds that blow ice away from the coast…

Complete press release: Changes in the Arctic: Consequences for the World (NASA Goddard Space Flight Centre)

Global warning has already hit the danger point that international attempts to curb it are designed to avoid, according to the world’s top climate watchdog.

Dr Rajendra Pachauri, the chairman of the official Intergovernmental Panel on Climate Change (IPCC), told an international conference attended by 114 governments in Mauritius this month that he personally believes that the world has “already reached the level of dangerous concentrations of carbon dioxide in the atmosphere” and called for immediate and “very deep” cuts in the pollution if humanity is to “survive”.

Complete article: Global warming approaching point of no return, warns leading climate expert (The Independent)

ITHACA, N.Y. — A Cornell University research group has made a sweet and environmentally beneficial discovery — how to make plastics from citrus fruits, such as oranges, and carbon dioxide.

In a paper published in a recent issue of the Journal of the American Chemical Society (Sept. 2004), Geoffrey Coates, a Cornell professor of chemistry and chemical biology, and his graduate students Chris Byrne and Scott Allen describe a way to make polymers using limonene oxide and carbon dioxide, with the help of a novel “helper molecule” — a catalyst developed in the researchers’ laboratory.

Limonene is a carbon-based compound produced in more than 300 plant species. In oranges it makes up about 95 percent of the oil in the peel.

In industry, Coates explains, the orange peel oil is extracted for various uses, such as giving household cleaners their citrus scent. The oil can be oxidized to create limonene oxide. This is the reactive compound that Coates and his collaborators used as a building block.

The other building block they used was carbon dioxide (CO2), an atmospheric gas that has been rising steadily over the past century and a half — due largely to the combustion of fossil fuels — becoming an environmentally harmful greenhouse gas.

By using their catalyst to combine the limonene oxide and CO2, the Coates group produced a novel polymer — called polylimonene carbonate — that has many of the characteristics of polystyrene, a petroleum-based plastic currently used to make many disposable plastic products.

“The polymer is a repeating unit, much like a strand of paper dolls. But instead of repeating dolls, the components alternate between limonene oxide and CO2 — in the polymer,” says Coates. Neither limonene oxide nor CO2 form polymers on their own, but when put together, a promising product is created.

“Almost every plastic out there, from the polyester in clothing to the plastics used for food packaging and electronics, goes back to the use of petroleum as a building block,” Coates observes. “If you can get away from using oil and instead use readily abundant, renewable and cheap resources, then that’s something we need to investigate. What’s exciting about this work is that from completely renewable resources, we were able to make a plastic with very nice qualities.”

The Coates research team is particularly interested in using CO2 as an alternative building block for polymers. Instead of being pumped into the atmosphere as a waste product, CO2 could be isolated for use in producing plastics, such as polylimonene carbonate.

The Coates laboratory comprises 18 chemists, about half of them striving to make recyclable and biodegradable materials out of cheap, readily available and environmentally friendly building blocks. “Today we use things once and throw them away because plastics are cheap and abundant. It won’t be like that in the future,” says Coates. “At some point we will look back and say, ‘Wow, remember when we would take plastic containers and just throw them away?’”

The research was supported by the Packard Foundation fellowship program, the National Science Foundation, the Cornell Center for Materials Research and the Cornell University Center for Biotechnology.

Reported and written by graduate student Sarah Davidson, a science writer intern with Cornell News Service.

Original press release: Sweet and environmentally beneficial discovery: Plastics made from orange peel and a greenhouse gas (Cornell University)

For the last three years evidence has been building that the impact of a comet or asteroid triggered the biggest mass extinction in Earth history, but new research from a team headed by a University of Washington scientist disputes that notion.

In a paper published Jan. 20 by Science Express, the online version of the journal Science, the researchers say they have found no evidence for an impact at the time of “the Great Dying” 250 million years ago. Instead, their research indicates the culprit might have been atmospheric warming because of greenhouse gases triggered by erupting volcanoes.

The extinction occurred at the boundary between the Permian and Triassic periods at a time when all land was concentrated in a supercontinent called Pangea. The Great Dying is considered the biggest catastrophe in the history of life on Earth, with 90 percent of all marine life and nearly three-quarters of land-based plant and animal life going extinct.

“The marine extinction and the land extinction appear to be simultaneous, based on the geochemical evidence we found,” said UW paleontologist Peter Ward, lead author of the paper. “Animals and plants both on land and in the sea were dying at the same time, and apparently from the same causes — too much heat and too little oxygen.”

The paper is to be published in the print edition of Science in a few weeks. Co-authors are Roger Buick and Geoffrey Garrison of the UW; Jennifer Botha and Roger Smith of the South African Museum; Joseph Kirschvink of the California Institute of Technology; Michael De Kock of Rand Afrikaans University in South Africa; and Douglas Erwin of the Smithsonian Institution.

The Karoo Basin of South Africa has provided the most intensively studied record of Permian-Triassic vertebrate fossils. In their work, the researchers were able to use chemical, biological and magnetic evidence to correlate sedimentary layers in the Karoo to similar layers in China that previous research has tied to the marine extinction at the end of the Permian period.

Evidence from the marine extinction is “eerily similar” to what the researchers found in the Karoo Basin, Ward said. Over seven years, they collected 126 reptile or amphibian skulls from a nearly 1,000-foot thick section of exposed Karoo sediment deposits from the time of the extinction. They found two patterns, one showing gradual extinction over about 10 million years leading up to the boundary between the Permian and Triassic periods, and the other for a sharp increase in extinction rate at the boundary that then lasted another 5 million years.

The scientists said they found nothing in the Karoo that would indicate a body such as an asteroid hit around the time of the extinction, though they looked specifically for impact clays or material ejected from a crater left by such an impact.

They contend that if there was a comet or asteroid impact, it was a minor element of the Permian extinction. Evidence from the Karoo, they said, is consistent with a mass extinction resulting from catastrophic ecosystem changes over a long time scale, not sudden changes associated with an impact.

The work, funded by the National Aeronautics and Space Administration’s Astrobiology Institute, the National Science Foundation and the National Research Foundation of South Africa, provides a glimpse of what can happen with long-term climate warming, Ward said.

In this case, there is ample evidence that the world got much warmer over a long period because of continuous volcanic eruptions in an area known as the Siberian Traps. As volcanism warmed the planet, large stores of methane gas frozen on the ocean floor might have been released to trigger runaway greenhouse warming, Ward said. But evidence suggests that species began dying out gradually as the planet warmed until conditions reached a critical threshold beyond which most species could not survive.

“It appears that atmospheric oxygen levels were dropping at this point also,” he said. “If that’s true, then high and intermediate elevations would have become uninhabitable. More than half the world would have been unlivable, life could only exist at the lowest elevations.”

He noted that the normal atmospheric oxygen level is around 21 percent, but evidence indicates that at the time of the Great Dying it dropped to about 16 percent — the equivalent of trying to breathe at the top of a 14,000-foot mountain.

“I think temperatures rose to a critical point. It got hotter and hotter until it reached a critical point and everything died,” Ward said. “It was a double-whammy of warmer temperatures and low oxygen, and most life couldn’t deal with it.”

Original press release: New evidence indicates biggest extinction wasn’t caused by asteroid or comet (University of Washington)

Golden, Colo. - A new integrated facility designed to give scientists unprecedented insights into the chemical and biological reactions which can transform renewable plant and waste materials into useful sources of energy was dedicated yesterday at the U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL).

Called the Biomass Surface Characterization Laboratory (BSCL), the $2.85 million facility features an array of electron and optical microscopes, and other advanced research tools, to probe biomass-to-energy processes at the most basic atomic and molecular levels.

“This unique laboratory will further enhance the capabilities of our world-class biomass research team,” said Michael Pacheco, director of the National Bioenergy Center, located at NREL. “It is our fervent hope that by assembling the best research equipment available within this new facility, we will hasten the day when our abundant biomass resources can be harnessed to cleanly and economically meet the nation’s critical energy needs.”

The new laboratory will support development of new technologies for bio-refineries - which will produce transportation fuels and a range of other products, much as a conventional oil refinery does today. Bio-refineries are to use renewable plant and waste materials instead of petroleum.

Officials from DOE’s Office of Biomass Programs and NREL participated in a dedication event for the new laboratory, which is housed within the Field Test Laboratory Building on NREL’s South Table Mountain campus.

“The leading edge tools, the advanced research and the skills and techniques that will be developed in this laboratory will allow technology developers to take biomass conversion technologies to the next level,” said Douglas Kaempf, manager of DOE’s Office of Biomass Programs.

“The investment required to develop this facility is testament to DOE’s commitment to integrating renewable energy into our nation’s energy infrastructure,” Kaempf said.

The highly sensitive instruments employed in the new laboratory must operate in a stringently controlled environment, and the BSCL includes systems to monitor and maintain temperature, humidity, acoustical vibration and cleanliness to the most exacting standards. Similarly, researchers using the lab will have at their disposal the latest computer hardware and software systems to capture, record and analyze the data they obtain.

Original press release: New Lab Delves into Plants for Fuels (NREL)

A long standing puzzle that has haunted climate researchers looking at the fate of carbon stored in the world’s soils, has now been resolved. The research suggests that climate warming may be occurring even faster than previously recognised.

The international team of researchers, led by Bristol University and reporting in Nature [20 January 2005], show that an apparent biological adaptation of micro-organisms that break down carbon in soils, thereby releasing carbon dioxide into the atmosphere, can in fact be explained by the widely contrasting properties of those organic carbons.

Recent reports of laboratory experiments have stated that the micro-organisms responsible for soil carbon decomposition gradually acclimatise to an increase in heat and adjust the rate at which carbon is released into the atmosphere, such that it is effectively released at a steady rate. However, this does not agree with long-established rules of physical chemistry that predict that as the climate warms these reactions should speed up, resulting in an increase in the amount of carbon dioxide released.

The team of researchers at Bristol University and the Natural Environment Research Council’s QUEST programme, the Max-Planck-Institute for Biogeochemistry in Germany, and the National Centre for Atmospheric Research in Colorado, has now managed to solve the puzzle, bringing the apparent contradictions from laboratory experiments in line with theoretical predictions.

They show that what looked liked a biological adaptation of the micro-organisms can in fact be explained by widely contrasting properties of organic carbon present in soils.

These properties range from highly digestible (labile) sugar-like compounds to almost stable, charcoal-like compounds which the micro-organisms have difficulty breaking down. Such an extreme mixture has so far prevented theoretical interpretation of the laboratory experiments.

Dr Wolfgang Knorr of Bristol University said: “The next step will be to apply the new theory in complex climate simulations, using so-called Earth System Models. So far, these models only use properties from the labile soil carbon because they are easier to measure. But an estimated 90% of the carbon locked up in the world’s soil is made up of the more stable components, which must now be built into the model.”

The new results predict that since the micro-organisms are not keeping the release of carbon dioxide from the soil at a steady state, as previously thought, an increase in climate temperatures will result in an increase in the rate at which the stable components decompose. This will lead to even more carbon dioxide being released into the atmosphere and more rapid climate change.

Original press release: Climate research breakthrough (Bristol University)