Fire Is Important Part of Global Climate Change

Report Scientists
April 23, 2009

(Santa Barbara, Calif.) –– Fire must be accounted for as an integral part of climate change, according to 22 authors of an article published in the April 24 issue of the journal Science. The authors determined that intentional deforestation fires alone contribute up to one-fifth of the human-caused increase in emissions of carbon dioxide, a heat-trapping gas that raises global temperature.

The work is the culmination of a meeting supported by the Kavli Institute for Theoretical Physics (KITP) and the National Center for Ecological Analysis and Synthesis (NCEAS), both based at UC Santa Barbara and funded by the National Science Foundation.

The authors call on the Intergovernmental Panel on Climate Change (IPCC) to fully integrate fire into their assessments of global climate change, and to consider fire-climate feedbacks, which have been largely absent in global models.

The article ties together various threads of knowledge about fire, which have, until now, remained isolated in disparate fields, including ecology, global modeling, physics, anthropology, and climatology.

Increasing numbers of wildfires are influencing climate as well, the authors report. "The tragic fires in Victoria, Australia, emphasize the ubiquity of recent large wildfires and potentially changing fire regimes that are concomitant with anthropogenic climate change," said first author David Bowman, professor at the University of Tasmania. "Our review is both timely and of great relevance globally."

Carbon dioxide is the most important and well-studied greenhouse gas that is emitted by burning plants. Other atmospheric changes caused by fires are increases in the greenhouse gas methane, increased aerosol particulates from smoke, and the changing reflectance of a charred landscape. Consequences of large fires also have huge economic, environmental, and health costs, report the authors.

The authors state, "Earth is intrinsically a flammable planet due to its cover of carbon-rich vegetation, seasonally dry climates, atmospheric oxygen, widespread lightning, and volcano ignitions. Yet, despite the human species' long-held appreciation of this flammability, the global scope of fire has been revealed only recently by satellite observations, available beginning in the 1980s."

They note, however, that satellites cannot adequately capture fire activity in ecosystems with very long fire intervals, or those with highly variable fire activity.

Co-lead author Jennifer Balch, a postdoctoral fellow at NCEAS, explains that there are bigger and more frequent fires from the western U.S. to the tropics. There are "fires where we don't normally see fires," she says, noting that in the humid tropics a lot of deforestation fires are occurring, usually to expand agriculture or cattle ranching. "Wet rainforests have not historically experienced fires at the frequency that they are today. During extreme droughts, such as in 97-98, Amazon wildfires burned through 39,000 square kilometers of forest."

She explains the importance of the article: "This synthesis is a prerequisite for adaptation to the apparent recent intensification of fire feedbacks, which have been exacerbated by climate change, rapid land cover transformation, and exotic species introductions –– that collectively challenge the integrity of entire biomes."

The authors acknowledge that their estimate of fire's influence on climate is just a start, and they highlight major research gaps that must be addressed in order to understand the complete contribution of fire to the climate system.

Balch notes that a holistic fire science is necessary, and points out fire's true importance. "We don't think about fires correctly," she said. "Fire is as elemental as air or water. We live on a fire planet. We are a fire species. Yet, the study of fire has been very fragmented. We know lots about the carbon cycle, the nitrogen cycle, but we know very little about the fire cycle, or how fire cycles through the biosphere."

Research Contacts:

Jennifer Balch is available at
(202) 360-0923 (cell),
(805) 892-2522 (office),
or balch@nceas.ucsb.edu


David Bowman is available at
042 88 94 500 (cell),
Tel (Int) +61 3 6226 1943,
Tel (Aus) 03 6226 1943,
or david.bowman@utas.edu.au

New Ocean Circulation Experiment has Potential Big Climate Model Impact

From: Editor, ENN, based on an artilce from eurekalert
Published May 15, 2009 02:00 PM

New research by Duke University, in conjunction with the Woods Hole Oceanographic Institution is casting doubt on long-held theories of North Atlantic Ocean circulation patterns. This research, supported by the National Science Foundation is important since oceanic circulation is one of the key factors in current atmospheric circulation models, and therefore critical starting points for climate modeling.


A 50-year-old model of ocean currents had shown this southbound subsurface flow of cold water forming a continuous loop with the familiar northbound flow of warm water on the surface, called the Gulf Stream.

"Everybody always thought this deep flow operated like a conveyor belt, but what we are saying is that concept doesn't hold anymore," said Duke oceanographer Susan Lozier. "So it's going to be more difficult to measure these climate change signals in the deep ocean."

And since cold Labrador seawater is thought to influence and perhaps moderate human-caused climate change, this finding may affect the work of global warming forecasters.


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"To learn more about how the cold deep waters spread, we will need to make more measurements in the deep ocean interior, not just close to the coast where we previously thought the cold water was confined," said Woods Hole's Amy Bower.

Lozier, a professor of physical oceanography at Duke's Nicholas School of the Environment and Bower, a senior scientist in the department of physical oceanography at the Woods Hole Institution, are co-principal authors of a report on the findings to be published in the May 14 issue of the research journal Nature.

For More: http://www.eurekalert.org/pub_releases/2009-05/du-cwo051309.php

NEW STORAGE SYSTEM DESIGN BRINGS HYDROGEN CARS CLOSER TO REALITY

Monday, 13 April 2009 14:14
Researchers have developed a critical part of a hydrogen storage system for cars that makes it possible to fill up a vehicle's fuel tank within five minutes with enough hydrogen to drive 300 miles.

The system uses a fine powder called metal hydride to absorb hydrogen gas. The researchers have created the system's heat exchanger, which circulates coolant through tubes and uses fins to remove heat generated as the hydrogen is absorbed by the powder.

The heat exchanger is critical because the system stops absorbing hydrogen effectively if it overheats, said Issam Mudawar, a professor of mechanical engineering who is leading the research.

"The hydride produces an enormous amount of heat," Mudawar said. "It would take a minimum of 40 minutes to fill the tank without cooling, and that would be entirely impractical."

Researchers envision a system that would enable motorists to fill their car with hydrogen within a few minutes. The hydrogen would then be used to power a fuel cell to generate electricity to drive an electric motor.

The research, funded by General Motors Corp. and directed by GM researchers Darsh Kumar, Michael Herrmann and Abbas Nazri, is based at the Hydrogen Systems Laboratory at Purdue's Maurice J. Zucrow Laboratories. In February, the team applied for three provisional patents related to this technology.

"The idea is to have a system that fills the tank and at the same time uses accessory connectors that supply coolant to extract the heat," said Mudawar, who is working with mechanical engineering graduate student Milan Visaria and Timothée Pourpoint, a research assistant professor of aeronautics and astronautics and manager of the Hydrogen Systems Laboratory. "This presented an engineering challenge because we had to figure out how to fill the fuel vessel with hydrogen quickly while also removing the heat efficiently. The problem is, nobody had ever designed this type of heat exchanger before. It's a whole new animal that we designed from scratch."

The metal hydride is contained in compartments inside the storage "pressure vessel." Hydrogen gas is pumped into the vessel at high pressure and absorbed by the powder.

"This process is reversible, meaning the hydrogen gas may be released from the metal hydride by decreasing the pressure in the storage vessel," Mudawar said. "The heat exchanger is fitted inside the hydrogen storage pressure vessel. Due to space constraints, it is essential that the heat exchanger occupy the least volume to maximize room for hydrogen storage."

Conventional automotive coolant flows through a U-shaped tube traversing the length of the pressure vessel and heat exchanger. The heat exchanger, which is made mostly of aluminum, contains a network of thin fins that provide an efficient cooling path between the metal hydride and the coolant.

"This milestone paves the way for practical on-board hydrogen storage systems that can be charged multiple times in much the same way a gasoline tank is charged today," said Kumar, a researcher at GM's Chemical & Environmental Sciences Laboratory and the GM R&D Center in Warren, Mich. "As newer and better metal hydrides are developed by research teams worldwide, the heat exchanger design will provide a ready solution for the automobile industry."

The researchers have developed the system over the past two years. Because metal hydride reacts readily with both air and moisture, the system must be assembled in an airtight chamber, Pourpoint said.

Research activities at the hydrogen laboratory involve faculty members from the schools of aeronautics and astronautics, mechanical engineering, and electrical and computer engineering.

http://news.uns.purdue.edu/x/2009a/090402MudawarHydrogen.html

ALGAE COULD FUEL CARS AND JOBS

(Photo: CSIRO)
Wednesday, 18 March 2009 17:32
CSIRO Energy Transformed researcher Dr Tom Beer and his team discovered the humble organisms’ green credentials during a detailed life-cycle analysis of the benefits of algal biodiesel.


"Our research has shown that under ideal conditions it is possible to produce algal biodiesel at a lower cost and with less greenhouse gas emissions than fossil diesel," Dr Beer said.

"The greenhouse gas reductions are the result of avoiding the use of a fossil resource for fuel production, capturing methane produced by the processed algae to generate energy and taking into account the potential greenhouse gas offsets from industry."

Algae thrive on carbon dioxide (CO2), which means that environmentally damaging CO2 emissions from industry could also become a useful resource.

Algal biodiesel could also offer a number of other benefits.

"Making biodiesel from algae removes the issue of competing land use because the facilities would not be established on land that might otherwise be used to grow food and the algal farm has a very low environmental impact in comparison to crops that are grown for biodiesel," Dr Beer said.

"Our study also found that the establishment of a 500 hectare algal biodiesel plant in a rural area might create up to 45 jobs and provide opportunities to diversify in the agricultural sector."

The CSIRO Energy Transformed Flagship is working with a number of partners, both national and international, to develop a strong algal biofuel research program.

"The Flagship’s research has made significant progress in a short time and our extensive biofuels program will continue to develop solutions that result in a secure fuel future for Australia," Dr Beer said.

Despite the global interest in the production of biodiesel from algae, further research is required to create a viable industry with widespread uptake and impact.

"Although the findings of our study are very promising, challenges still exist in relation to cost, infrastructure needs and the scale of production required to make algal plants feasible," Dr Beer said.

"We see biodiesel from algae as one potential option for sustainable fuel production amongst a range of other technologies."

CSIRO

SUNLIGHT TURNS CARBON DIOXIDE TO METHANE

(Photo: Penn State)
Tuesday, 17 March 2009 16:18

Burning fossil fuels like oil, gas and coal release large amounts of carbon dioxide, a greenhouse gas, into the atmosphere. Rather than contribute to global climate change, producers could convert carbon dioxide to a wide variety of hydrocarbons, but this makes sense to do only when using solar energy.


"Recycling of carbon dioxide via conversion into a high energy-content fuel, suitable for use in the existing hydrocarbon-based energy infrastructure, is an attractive option, however the process is energy intense and useful only if a renewable energy source can be used for the purpose," the researchers note in a recent issue of Nano Letters.

Craig A. Grimes, professor of electrical engineering and his team used titanium dioxide nanotubes doped with nitrogen and coated with a thin layer of both copper and platinum to convert a mixture of carbon dioxide and water vapor to methane. Using outdoor, visible light, they reported a 20-times higher yield of methane than previously published attempts conducted in laboratory conditions using intense ultraviolet exposures.

The chemical conversion of water and carbon dioxide to methane is simple on paper -- one carbon dioxide molecule and two water molecules become one methane molecule and two oxygen molecules. However, for the reaction to occur, at least eight photons are required for each molecule.

"Converting carbon dioxide and water to methane using photocatalysis is an appealing idea, but historically, attempts have had very low conversion rates," said Grimes who is also a member of Penn State's Materials Research Institute. "To get significant hydrocarbon reaction yields requires an efficient photocatalyst that uses the maximum energy available in sunlight."

The team, which also included Oomman K. Varghese and Maggie Paulose, Materials Research Institute research scientists and Thomas J. LaTempa, graduate student in electrical engineering, used natural sunlight to test their nanotubes in a chamber containing a mix of water vapor and carbon dioxide. They exposed the co-catalyst sensitized nanotubes to sunlight for 2.5 to 3.5 hours when the sun produced between 102 and 75 milliwatts for each square centimeter exposed.

The researchers found that nanotubes annealed at 600 degrees Celsius and coated with copper yielded the highest amounts of hydrocarbons and that the same nanotubes coated with platinum actually yielded more hydrogen, while the copper coated nanotubes produced more carbon monoxide. Both hydrogen and carbon monoxide are normal intermediate steps in the process and as the building blocks of syngas, can be used to make liquid hydrocarbon fuels.

When the team used a nanotube array with about half the surface coated in copper and the other half in platinum, they enhanced the hydrocarbon production and eliminated carbon monoxide. The yield for these dual catalyst nanotubes was 163 parts per million hydrocarbons an hour for each square centimeter. The yield from titania nanotubes without either copper or platinum catalysts is only about 10 parts per million.

"If we uniformly coated the surface of the nanotube arrays with copper oxide, I think we could greatly improve the yield," said Grimes.

Grimes also found that lengthening the titanium dioxide tubes, which for other applications increases yield, does not improve results.

"We think that distribution of the sputtered catalyst nanoparticles is at the top surface of the nanotubes and not inside and that is why increased length does not improve the reaction," says Grimes.

Although all these experiments were done with nitrogen-doped titanium dioxide nanotubes, the researchers conclude that the nitrogen did not enhance the conversion of carbon dioxide to hydrocarbons. The catalysts, however, did shift the reaction from one that used only the energy in ultraviolet light to one that used other wavelengths of visible light and therefore more of the sun's energy.

The researchers are now working on converting their batch reactor into a continuous flow-through design that they believe will significantly increase yields.

The researchers have filed a provisional patent on this work.

Penn State

U.S.-LED, INTERNATIONAL RESEARCH TEAM CONFIRMS ALPS-LIKE MOUNTAIN RANGE EXISTS UNDER EAST ANTARCTIC

(Photo: Zina Deretsky / NSF)

Wednesday, 11 March 2009 10:33
Flying twin-engine light aircraft the equivalent of several trips around the globe and establishing a network of seismic instruments across an area the size of Texas, a U.S.-led, international team of scientists has not only verified the existence of a mountain range that is suspected to have caused the massive East Antarctic Ice Sheet to form, but also has created a detailed picture of the rugged landscape buried under more than four kilometers (2.5 miles) of ice.

"Working cooperatively in some of the harshest conditions imaginable, all the while working in temperatures that averaged -30 degrees Celsius, our seven-nation team has produced detailed images of last unexplored mountain range on Earth," said Michael Studinger, of Columbia University's Lamont-Doherty Earth Observatory, the co-leader of the U.S. portion of the Antarctica's Gamburstev Province (AGAP) project. "As our two survey aircraft flew over the flat white ice sheet, the instrumentation revealed a remarkably rugged terrain with deeply etched valleys and very steep mountain peaks."

The National Science Foundation (NSF), in its role as manager of the U.S. Antarctic Program, provided much of the complex logistical support that made the discoveries possible. NSF also supported U.S. researchers from Columbia University, Washington University in St. Louis, Pennsylvania State University, the Center for Remote Sensing of Ice Sheets (CReSIS) at the University of Kansas, the U.S. Geological Survey (USGS) and the Incorporated Research Institutions in Seismology (IRIS).

The initial AGAP findings--which are based on both the aerogeophysical surveys and on data from a network of seismic sensors deployed as part of the project--while extremely exciting, also raise additional questions about the role of the Gamburtsevs in birthing the East Antarctic Ice Sheet, which extends over more than 10 million square kilometers atop the bedrock of Antarctica, said geophysicist Fausto Ferraccioli, of the British Antarctic Survey (BAS), who led the U.K. science team.

"We now know that not only are the mountains the size of the European Alps but they also have similar peaks and valleys," he said. "But this adds even more mystery about how the vast East Antarctic Ice Sheet formed."

He added that "if the ice sheet grew slowly then we would expect to see the mountains eroded into a plateau shape. But the presence of peaks and valleys could suggest that the ice sheet formed quickly--we just don't know. Our big challenge now is to dive into the data to get a better understanding of what happened" millions of years ago.

The AGAP survey area covered roughly 2 million square kilometers of the ice sheet.

The initial data also appear to confirm earlier findings that a vast aquatic system of lakes and rivers exists beneath the ice sheet of Antarctica, a continent that is the size of the U.S. and Mexico combined.

"The temperatures at our camps hovered around -30 degrees Celsius, but three kilometers beneath us at the bottom of the ice sheet we saw liquid water in the valleys," said AGAP U.S. Co-leader Robin Bell, also of Lamont Doherty. "The radar mounted on the wings of the aircraft transmitted energy through the thick ice and let us know that it was much warmer at the base of the ice sheet."

The AGAP data will help scientists to determine the origin of the East Antarctic Ice Sheet and the Gamburtsevs' role in it. It will also help them to understand the role the subglacial aquatic system plays in the dynamics of ice sheets, which will, in turn, help reduce scientific uncertainties in predictions of potential future sea level rise. The most recent report of the Intergovernmental Panel on Climate Change (IPCC) said that it is difficult to predict how much the vast ice sheets of Greenland and Antarctica will contribute to sea-level rise because so little is known about the behavior of the ice sheets.

The data also will be used to help locate where the world's oldest ice is located.

The AGAP discoveries were made through fieldwork that took place in December and January, near the official conclusion of the International Polar Year (IPY), the largest coordinated international scientific effort in five decades. Ceremonies marking the conclusion of IPY fieldwork will take place in Geneva, Switzerland on Feb. 25.

NSF is the lead U.S. agency for IPY. Through the Antarctic Program, NSF manages all federally funded research on the southernmost continent.

Fully in the spirit of IPY, noted Detlef Damaske of Germany's Federal Institute for Geosciences and Natural Resources, teams of scientists, engineers, pilots and support staff from Australia, Canada, China, Germany, Japan, the U.K. and the U.S. pooled their knowledge, expertise and logistical resources to deploy two survey aircraft, equipped with ice-penetrating radar, gravimeters and magnetic sensors as well as the network of seismometers, an effort that no one nation alone could have mounted.

"This is a fantastic finale to IPY," added Ferraccioli.

Bell meanwhile, noted that AGAP is "emblematic of what the international science community can accomplish when working together."

In one of the most ambitious, challenging and adventurous 'deep field' Antarctic IPY expeditions, AGAP scientists gathered the terabytes of data needed to create images of the enigmatic Gamburtsevs, first discovered by Russian scientists in 1957 during the International Geophysical Year (IGY), the predecessor to IPY.

While the planes made a series of survey flights, covering a total of 120,000 square kilometers, the seismologists flew to 26 different sites throughout an area larger than the state of Texas using Twin Otter aircraft equipped with skis, to install scientific equipment that will run for the next year on solar power and batteries.

The seismology team, from Washington University, Penn State, IRIS, and Japan's National Institute of Polar Research, also recovered ten seismographs that have been collecting data since last year over the dark Antarctic winter at temperatures as low as -73 degrees Celsius (-100 degrees Fahrenheit).

"The season was a great success," said Douglas Wiens, of Washington University in St. Louis. "We recovered the first seismic recordings from this entire part of Antarctica, and operated seismographs over the Antarctic winter at temperatures as low as -100 F for the first time. Now, we are poring over the data to find out what is responsible for pushing up mountains in this part of Antarctica."

National Science Foundation

MICROBE SURVIVES IN OCEAN'S DEEPEST REALM, THANKS TO GENETIC ADAPTATIONS

Photo: University of Delaware

Friday, 27 February 2009 00:34
The genome of a marine bacterium living 2,500 meters below the ocean's surface is providing clues to how life adapts in extreme environments, according to a paper published Feb. 6, 2009, in the journal PLoS Genetics.


The research focused on the bacterium Nautilia profundicola, a microbe that survives near deep-sea hydrothermal vents. It was found in a fleece-like lining on the backs of Pompeii worms, a type of tubeworm that lives at hydrothermal vents, and in bacterial mats on the surfaces of the vents' chimney structures.

One gene, called rgy, allows the bacterium to manufacture a protein called reverse gyrase when it encounters extremely hot fluids from the Earth's interior released from the sea floor.

"The discovery of reverse gyrase in Nautilia profundicola suggests that it plays a key role in this microbe's ability to thrive near deep-sea hydrothermal vents, where conditions are thought to resemble those found on early Earth," said Matt Kane, program director in the National Science Foundation (NSF)'s Division of Environmental Biology, which funded the research. "Knowledge of microbes living near vents may aid our understanding of how life evolved."

The study involved scientists at the University of Delaware, the University of California, the Universities of Louisville, Ky., and Waikato, New Zealand, and the J. Craig Venter Institute.

They combined genome analysis with physiological and ecological observations to investigate the importance of one gene, rgy, in N. profundicola's ability to adapt to the extreme changes it's exposed to in the deep sea.

"Previous studies found the gene only in microorganisms growing in temperatures greater than 80 degrees Celsius, but Nautilia profundicola thrives best at much lower temperatures," said Barbara Campbell, a marine scientist at the University of Delaware.

"The gene's presence in Nautilia profundicola suggests that it might play a role in the bacterium's ability to survive rapid and frequent temperature fluctuations in its environment."

Photosynthesis doesn't occur in this dark environment, where hot, toxic fluids oozing from below the seafloor combine with cold seawater at very high pressures.

Microorganisms that thrive at hydrothermal vents must adapt to fluctuations in temperature and oxygen levels, ranging from the hot, sulfide- and heavy metal-laden plume at the vents' outlets to cold seawater in the surrounding region.

The researchers uncovered further adaptations to the vent environment in Nautilia profundicola, including genes necessary for growth and for sensing environmental conditions. They also proposed a new route for bacterial nitrate assimilation related to how other bacteria use ammonia as an energy source.

Nautilia profundicola contains all the genes necessary for life in conditions widely believed to mimic those in our planet's early biosphere.

"It will be an important model system," said Campbell, "for understanding early microbial life on Earth."



The National Science Foundation