Global Warming – Climate Change News : Increased Carbon Dioxide In Atmosphere Linked To Decreased Soil Organic Matter, Decreased Plant Growth

A recent study at the University of Illinois created a bit of a mystery for soil scientist Michelle Wander — increased carbon dioxide in the atmosphere was expected to increase plant growth, increase plant biomass and ultimately beef up the organic matter in the soil — but it didn’t. What researchers found instead was that organic matter decay increased along with residue inputs when carbon dioxide levels were increased and they think the accelerated decay was due to increased moisture in the soil.

“Going into the study, the assumption was that higher levels of carbon dioxide in the atmosphere will increase crop yield and soil organic matter,” said Wander. “We did see a 30 percent increase in above- and below- ground soybean biomass so we expected that to be mirrored in soil organic matter, but there wasn’t an increase. In fact, organic matter levels may have even been lower than in plots not exposed to elevated carbon dioxide levels.”

The study was conducted at U of I’s SoyFACE facility — an open air laboratory in which rings of pipes surround corn and soybean crops and can be exposed to various levels of carbon dioxide, ozone or both pumped through the pipes.

“My student Adriane Peralta and I were looking at younger soil organic matter that would be most influenced by today’s practices and we were expecting a big change — a 30 percent increase in soil organic matter, reflecting the changes we saw above ground.

“The source of carbon is plant biomass, so we would expect increased yield, increased biomass, increased soil organic matter in the soil. This kind of positive feedback would be good because it could offset the increases in decay that will result from rising temperature,” said Wander. She explained that the increases in carbon dioxide levels in the atmosphere insulate the earth and contribute to global warming. Average annual air and soil temperatures are increasing while winters are getting shorter. By the end of the century, maximum daily temperatures could rise by 5 to 12 degrees Fahrenheit in winter and 5 to 20 degrees Fahrenheit in summer.

“We know that microbial activity is directly influenced by an increase in temperature if other factors, like moisture aren’t limiting their growth,” she said. “Increased decomposition of organic matter is undesirable from a soil quality and climate perspective; microbial degradation of organic stocks releases carbon and nitrogen and over the long term this reduces soil’s productivity and ability to resist erosion, plus it returns the carbon dioxide to the atmosphere.” All of this talk about using agricultural lands to mitigate climate change depends upon our ability to keep the carbon in soil reserves.

Wander said that carbon dioxide is rising every year in the atmosphere because of human use of fossil fuel and deforestation. “We attribute the higher soybean yields over the past several decades to the rising carbon dioxide levels in the Earth’s atmosphere — some attribute a 10 percent increase in soybean yields already due to this carbon dioxide fertilization effect.

“Most models or projections of the future assume the carbon dioxide fertilization effect would be a good thing for agriculture and the world’s food supply and have a benefit to soil organic matter, but more and more we are finding things are a little more complicated. What our study shows is that in this system, rising carbon dioxide levels are not contributing to soil health after all.

“So, we had a bit of a mystery to solve. Where did the organic carbon that was added by increased plant growth go” We know for certain that soil organic matter stocks result from the balance of inputs and decay so we had to look at factors influence decomposition. Nutrient levels soil pH and available N were all high in this fertile field and so we ruled these factors out.”

Wander and Peralta suspect soil moisture plays a role. Wander points out that changes in rainfall are another important aspect of climate change and notes that we are already seeing shifts in the distribution of rainfall with increases in winter and spring rains with drier summers. Dry conditions can constrain plant growth and microbial decay rates. So, what they saw in the SoyFACE plots, was evidence of an important feedback — where crops exposed to elevated carbon dioxide became more water use efficient.

“When plants take up moisture they open their stomata — the pores through which they transport both carbon dioxide and water and when plants satisfy their need for carbon dioxide they can close those stomata and conserve water. This appears to have happened at SoyFACE in both corn and soybean crops. So, moisture feedbacks that increased microbial activity might solve the mystery”. Wander said it’s a little tricky to project the future with these findings, because they are manipulating carbon dioxide but not rainfall in the SoyFACE test plots.

“We have learned that we can’t say ‘yield equals organic matter.’ We have to understand the nuances of the time and place. SoyFACE is giving us early clues about what could happen in the future and where to direct our research attentions.” The frontier of science right now includes anticipation of these interactions –reality might be stranger than the fiction that we create in the laboratory- even in an open field study like SoyFACE.

The findings from the study are published in the February issue of Plant and Soil.

Adapted from materials provided by University of Illinois at Urbana-Champaign.

Source: http://www.sciencedaily.com/releases/2008/03/080311123413.htm

Global Warming News : Promising New Material For Capturing Carbon Dioxide From Smokestacks

Scientists and engineers in Georgia and Pennsylvania are reporting development of a new, low-cost material for capturing carbon dioxide from the smokestacks of coal-fired electric power plants and other industrial sources before the notorious greenhouse gas enters the atmosphere.

In the new study, Christopher W. Jones and colleagues point out that existing carbon capture technology is unsuitable for wide use. Absorbent liquids, for instance, are energy intensive and expensive. Current solid adsorbents show promise, but many suffer from low absorption capacities and lack stability after extended use. Stronger, longer-lasting materials are needed, scientists say.

The scientists describe development of a new solid adsorbent coined a hyperbranched aminosilica (HAS) that avoids those problems. When compared to traditional solid adsorbents under simulated emissions from industrial smokestacks, the new material captured up to seven times more carbon dioxide than conventional solid materials, including some of the best carbon dioxide adsorbents currently available, the researchers say. The material also shows greater stability under different temperature extremes, allowing it to be recycled numerous times.

The article “Designing Adsorbents for CO₂ Capture from Flue Gas-Hyperbranched Aminosilicas Capable of Capturing CO₂ Reversibly” is scheduled for the March 19 issue of the ACS’ Journal of the American Chemical Society.

Adapted from materials provided by American Chemical Society, via EurekAlert!, a service of AAAS.

Source: http://www.sciencedaily.com/releases/2008/03/080303163804.htm

Global Warming News : Turning Carbon Dioxide into Gasoline!

Anyone need a ride?

A pair of scientists at the Los Alamos National Laboratory have come up with a concept for removing carbon dioxide from the air and turning it back into gasoline!

The scientists, Jeffrey Martin and William Kubic Jr. have titled their concept “Green Freedom“, and here is how it would work. Air would be blown over a liquid solution of potassium carbonate, which would absorb the carbon dioxide. The carbon dioxide would then be extracted and subjected to chemical reactions that would turn it into fuel such as methanol, gasoline and jet fuel. The closed cycle – meaning equal amounts of carbon dioxide emitted and removed from the air would mean that cars, trucks and airplanes using the synthetic fuels would no longer contribute to global warming, according to the New York Times article.

I know, you’re saying that there must be a catch, well sort of……..no prototype has yet to be built, but the scientists say it is all based on existing technology. One major caveat to building a (CO2 to gasoline) factory is that it would require a great deal of energy. A nuclear power plant and the development of a new electrochemical process might be able to overcome that obstacle.

The Los Alamos proposal does not violate any laws of physics, and other scientists, like George A. Olah, a Nobel Prize-winning chemist at the University of Southern California, and Klaus Lackner, a professor of geophysics at Columbia University, have independently suggested similar ideas. Dr. Martin said he and Dr. Kubic had worked out their concept in more detail than previous proposals.

What would be the cost of the project? About 5 billion.

The concept would be able to produce gasoline at a cost of $1.40 per gallon and it would be made economically viable at a cost of $4.60 to the consumer. Technology advances might be able to get that cost down to $3.40.

Source: http://global-warming.accuweather.com/

Global Warming News : Offsetting Global Warming By Trapping Carbon Dioxide On The Bottom Of The Ocean

ScienceDaily (Feb. 19, 2008) — Imagine a gigantic, inflatable, sausage-like bag capable of storing 160 million tonnes of CO₂ — the equivalent of 2.2 days of current global emissions. Now try to picture that container, measuring up to 100 metres in radius and several kilometres long, resting benignly on the seabed more than 3 kilometres below the ocean’s surface.

At first blush, this might appear like science fiction, but it’s an idea that gets serious attention from Dr. David Keith, one of Canada’s foremost experts on carbon capture and sequestration. Keith will talk on the subject at the 2008 Annual Conference of the American Association for the Advancement of Science in Boston at a session entitled Ocean Iron Fertilization and Carbon Sequestration: Can the Oceans Save the Planet?

“There are a lot of gee-whiz ideas for dealing with global warming that are really silly,” remarks Keith, an NSERC grantee and director of the Energy and Environmental Systems Group at University of Calgary-based Institute for Sustainable Energy, Environment and Economy. “At first glance this idea looks nutty, but as one looks closer it seems that it might technically feasible with current-day technology.” But, adds Keith, who holds the Canada Research Chair in Energy and the Environment, “it’s early days and there is not yet any serious design study for the concept.”

The original idea of ocean storage was conceived several years ago by Dr. Michael Pilson, a chemical oceanographer at the University of Rhode Island, but it really took off last year when Keith confirmed its feasibility with Dr. Andrew Palmer, a world-renowned ocean engineer at Cambridge University. Keith, Palmer and another scientist at Argonne National Laboratory later advanced the concept through a technical paper prepared for the 26th International Conference on Offshore Mechanics and Arctic Engineering in June 2007.

Keith sees this solution as a potentially useful complement to CO₂ storage in geological formations, particularly for CO₂ emanating from sources near deep oceans.

He believes it may offer a viable solution because vast flat plains cover huge areas of the deep oceans. These abyssal plains have little life and are benign environments. “If you stay away from the steep slopes from the continental shelves, they are a very quiet environment.”

For CO₂ to be stored there, the gas must be captured from power and industrial point sources, compressed to liquid, and transported via pipelines that extend well beyond the ocean’s continental shelves. When the liquid CO₂ is pumped into the deep ocean, the intense pressure and cold temperatures make it negatively buoyant.

“This negative buoyancy is the key,” explains Keith. “It means the CO₂ wants to leak downwards rather than moving up to the biosphere.”

The use of containment is necessary because CO₂ will tend to dissolve in the ocean, which could adversely impact marine ecosystems. Fortunately, says Keith, the cost of containment is quite minimal with this solution. He and his colleagues calculate that the bags can be constructed of existing polymers for less than four cents per tonne of carbon.

The real costs lie in the capture of CO₂ and its transport to the deep ocean. “If we can drive those down,” he notes, “then ocean storage might be an important option for reducing CO₂ emissions.”

Adapted from materials provided by Natural Sciences and Engineering Research Council.

Source: http://www.sciencedaily.com/releases/2008/02/080218134635.htm