Iceland has Demonstrated how to Sequester and Convert Carbon dioxide to Stone

cientists and engineers working at a major power plant in Iceland have shown for the first time that carbon dioxide emissions can be pumped into the earth and changed chemically to a solid within months--radically faster than anyone had predicted. The finding may help address a fear that so far has plagued the idea of capturing and storing CO2 underground: that emissions could seep back into the air or even explode out. A study describing the method appears this week in the leading journal Science.

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Regrowing Latin American Forests Could Significantly Help With Global Warming

Forests re-grown on lands that had been cleared for agriculture in Latin America could play a key role in trapping carbon from the atmosphere and mitigating climate change if they are managed properly, researchers said in a study published on Friday.

Over the next 40 years, such second-growth forests have the potential to sequester greenhouse gas emissions equivalent to all fossil fuel and industrial emissions from Latin America in the past two decades, said the study by scientists at the University of Connecticut.

While preventing deforestation is the best protection against releasing climate-changing gases, the study published in the journal Science Advances shows that re-grown forests have a bigger impact in combating global warming than previously thought.

"Avoiding deforestation and supporting forest regeneration are complementary and mutually reinforcing activities," said Robin Chazdon, a professor of evolutionary biology at the University of Connecticut and lead author of the study.

For re-growing forests to live up to their potential in sucking carbon out of the atmosphere in the tropics, governments across Latin America need to work with local communities to ensure the land is protected, Chazdon said.

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Dynamic Landscapes are the Biggest Carbon Sinks in the Eastern United States

The strongest forest carbon sinks in eastern forests are within landscapes not completely dominated by forests. Using a new framework for forest carbon accounting, a team of USDA Forest Service scientists found that landscapes with 50-60 percent forest land use had statistically the same sink strength as landscapes with 90-100 percent forest.

"Monitoring Network Confirms Land Use Change is a Substantial Component of the Forest Carbon Sink in the Eastern United States," a study by Forest Service scientists and collaborators, describes land use change as a substantial part of a strong forest carbon sink in the Eastern United States.

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Did Mars NEVER Have a Thick Atmosphere? Nili Fossae on Mars Only Seems to Sequester 12 mbar of CO2 (max)

Carbon sequestration on Mars

Authors:

Edwards et al

Abstract:

On Earth, carbon sequestration in geologic units plays an important role in the carbon cycle, scrubbing CO2 from the atmosphere for long-term storage. While carbonate is identified in low abundances within the dust and soils of Mars, at less than 1 wt% in select meteorites, and in limited outcrops, no massive carbonate rock reservoir on Mars has been identified to date. Here, we investigate the largest exposed carbonate-bearing rock unit, the Nili Fossae plains, combining spectral, thermophysical, and morphological analyses to evaluate the timing and carbon sequestration potential of rocks on Mars. We find that the olivine-enriched (∼20%–25%) basalts have been altered, by low-temperature in-situ carbonation processes, to at most ∼20% Fe-Mg carbonate, thus limiting carbon sequestration in the Nili Fossae region to ∼0.25–12 mbar of CO2 during the late Noachian–early Hesperian, before or concurrent with valley network formation. While this is large compared to modern-day CO2 reservoirs, the lack of additional, comparably sized post–late Noachian carbonate-bearing deposits on Mars indicates ineffective carbon sequestration in rock units over the past ∼3.7 b.y. This implies a thin atmosphere (≲500 mbar) during valley network formation, extensive post-Noachian atmospheric loss to space, or diffuse, deep sequestration by a yet-to-be understood process. In stark contrast to Earth's biologically mediated crust:atmosphere carbon reservoir ratio of ∼104–105, Mars' ratio is a mere ∼10–103, even if buried pre-Noachian crust holds multiple bars.

Early Terrestrial Plants Could NOT Have Caused the Ordovician Glaciations

Constraining the role of early land plants in Palaeozoic weathering and global cooling

Authors:

Quirk et al

Abstract:

How the colonization of terrestrial environments by early land plants over 400 Ma influenced rock weathering, the biogeochemical cycling of carbon and phosphorus, and climate in the Palaeozoic is uncertain. Here we show experimentally that mineral weathering by liverworts—an extant lineage of early land plants—partnering arbuscular mycorrhizal (AM) fungi, like those in 410 Ma-old early land plant fossils, amplified calcium weathering from basalt grains threefold to sevenfold, relative to plant-free controls. Phosphate weathering by mycorrhizal liverworts was amplified 9–13-fold over plant-free controls, compared with fivefold to sevenfold amplification by liverworts lacking fungal symbionts. Etching and trenching of phyllosilicate minerals increased with AM fungal network size and atmospheric CO2 concentration. Integration of grain-scale weathering rates over the depths of liverwort rhizoids and mycelia (0.1 m), or tree roots and mycelia (0.75 m), indicate early land plants with shallow anchorage systems were probably at least 10-fold less effective at enhancing the total weathering flux than later-evolving trees. This work challenges the suggestion that early land plants significantly enhanced total weathering and land-to-ocean fluxes of calcium and phosphorus, which have been proposed as a trigger for transient dramatic atmospheric CO2 sequestration and glaciations in the Ordovician.

Oceanic Carbon Uptake Varies

The Earth's oceans are thought to have taken up about one quarter of the carbon dioxide (CO2) that humans pumped into the atmosphere in the past 2 decades. While this drives acidification and has consequences for sea life, it also moderates the rate of climate change.

Researchers recently set out to create a global model of CO2 uptake using fine-scale observations on a global scale. Between 1998 and 2011, they found strong interannual variations, with the Pacific Ocean dominating the global flux variability.

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Oceanic Iron Fertilization Less Efficient Than Thought for Carbon Sequestration

The Southern Ocean plays an important role in the exchange of carbon dioxide between the atmosphere and the ocean. One aspect of this is the growth of phytoplankton, which acts as a natural sponge for carbon dioxide, drawing the troublesome greenhouse gas from the atmosphere into the sea. When these plankton die they can sink to the bottom of the ocean and store some of the carbon dioxide they have absorbed, a process scientists call the "biological carbon pump".

Although many areas of the Southern Ocean are rich in nutrients, they often lack iron, which limits phytoplankton growth. An important idea in oceanography is that adding iron to the Southern Ocean could stimulate phytoplankton growth and the biological carbon pump. Some scientists believe that this process can partly explain cycles in atmospheric carbon dioxide over Earth's recent history and it has also been widely debated as a mitigation strategy for climate change.

In two previous studies carried out in the last five years it has been shown that iron fertilization of the Southern Ocean can export carbon dioxide to the deep-sea. "However, to understand the net storage of carbon dioxide in the ocean interior, sinking phytoplankton are only one part of the story", explains Dr. Ian Salter from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research. "These phytoplankton can be a food source for certain types of planktonic grazers, foraminifer and pteropods, that make shells from calcium carbonate - a process which produces carbon dioxide".

The biogeochemist, and an international team of collaborators, were the first to quantify production and sinking of these calcium carbonate shells resulting from a phytoplankton bloom in the Southern Ocean, close to the Crozet Islands, with surprising results. Natural fertilization, caused by iron leached from the basaltic islands, increased the production and sinking of these calcium carbonate shells to a greater extent than sinking phytoplankton. This has important implications for the deep-sea storage of the carbon dioxide resulting from these blooms.

"The production and sinking of these calcium carbonate shells affects the balance of carbon dioxide in the surface ocean over 100 to 1000 year timescales", explains Dr. Ian Salter. "Our calculations suggest that this process reduces the amount of carbon dioxide transferred to the ocean interior via sinking phytoplankton by up to 30 per cent in this naturally fertilized system. However, it is unclear that purposefully added iron would have the same impact."

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Fresh Water Lakes Played an Important Role in the Proterozoic Great Oxygenation Events

Enhanced organic carbon burial in large Proterozoic lakes: Implications for atmospheric oxygenation

Authors:

Spinks et al

Abstract:

The burial of organic carbon in sedimentary systems has been a fundamental part of the carbon cycle throughout the geological record, and was instrumental in major oxygenations of the atmosphere in the early Palaeoproterozoic and Neoproterozoic. While much focus has been placed on the burial of carbon in Precambrian marine carbonate and organic carbon-rich rocks deposited around the time of these major oxygenations, such deposits yield little information on the evolution of the atmosphere in the significant time between. There is, however, growing evidence from terrestrially deposited sediments to suggest the surface environment may have been at least intermittently well-oxygenated from the late Mesoproterozoic. Hence Proterozoic sediments deposited in terrestrial near-surface environments are useful targets for the study of atmospheric evolution during a time which is hitherto poorly understood.

Thus far, little attention has been paid to the contribution of large lakes and intercontinental basins to the global burial of organic carbon, and thus the progressive oxygenation of the atmosphere, especially given that the highest rates of organic carbon burial in modern aquatic environments occur in lacustrine settings, in stark contrast to the low rates observed in the contemporary marine realm. Here, we report high burial rates of organic carbon in large lacustrine systems of late Mesoproterozoic to early Neoproterozoic age, which are comparable with modern lacustrine systems, and significantly higher than modern and ancient marine deposits. These data emphasise the significance of lakes as a global repository for organic carbon, and imply Proterozoic lakes were at least as efficient, and perhaps as important, as modern lakes in the global burial of organic carbon. Such findings suggest large Proterozoic lakes and epicontinental basins played a crucial role in the progressive oxygenation of the atmosphere before the major Neoproterozoic oxygenation.

A Call for Carbon Capture to Mitigate Global Warming

Wally Broeker, the first person to alert the world to Global Warming, has called for atmospheric CO2 to be captured and stored underground. He says that Carbon Capture, combined with limits on fossil fuel emissions, is the best way to avoid global warming getting out of control over the next fifty years. Professor Broeker (Columbia University, New York) made the call during his presentation to the International Carbon Conference in Reykjavik, Iceland, where 150 scientists are meeting to discuss Carbon Capture and Storage.

He was presenting an analysis which showed that the world has been cooling very slowly, over the last 51 million years, but that human activity is causing a rise in temperature which will lead to problems over the next 100,000 years.

"We have painted ourselves into a tight corner. We can't reduce our reliance of fossil fuels quickly enough, so we need to look at alternatives.

"One of the best ways to deal with this is likely to be carbon capture – in other words, putting the carbon back where it came from, underground. There has been great progress in capturing carbon from industrial processes, but to really make a difference we need to begin to capture atmospheric CO2. Ideally, we could reach a stage where we could control the levels of CO2 in the atmosphere, like you control your central heating. Continually increasing CO2 levels means that we will need to actively manage CO2 levels in the environment, not just stop more being produced. The technology is proven, it just needs to be brought to a stage where it can be implemented.

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Planting Shrubs Along US Highways Would Sequester up to 7 Million Tons of Carbon

As you watch the miles roll by on family road trips this summer, look just behind the guard rails to see what some scientists believe is a significant untapped resource in the battle against climate change.

The land alongside the 4 million miles of U.S. public roadways, already being maintained by federal, state, and local governments, could be planted with vegetation that helps transfer carbon from the atmosphere into the soil, they say. Road banks and berms, in other words, could be managed as valuable "banks" for carbon sequestration.

"We're talking millions of acres," says biologist Rob Ament, of the Western Transportation Institute at Montana State University, who led a recent study to gauge carbon storage potential on just a fraction of that real estate – roadsides on federal lands.

Shrubs, grasses, and other plants already along roads in U.S. National Parks, wildlife refuges, and other public lands currently are capturing about 7 million metric tons of carbon each year, Ament said in a report on his findings at this month's North American Congress for Conservation Biology in Missoula. That's equivalent to the annual carbon emissions of 5 million cars—without any effort made to optimize the mix of plantings and soil management practices for carbon storage.

Add to that the strips of shrubbery and grass along U.S. highways outside federal lands. A previous study by the Federal Highway Administration concluded such roadside greenery stores enough carbon to counter the annual emissions of 2.6 million passenger cars.

Together, the roadside soils and vegetation on federal lands and along U.S. highways, comprising 10.5 percent of all public roads in the nation, are already capturing nearly 2 percent of total U.S. transportation carbon emissions, said Ament, whose team conducted the research for the Highway Administration's federal lands office.

"There is a significant amount of [carbon capture and sequestration] going on right now, passively," Ament said in an interview. "So the next step is to research active management techniques and take a good hard look at what's possible."

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ReGrowing Tropical Rain Forests Recover Carbon Storage Quickly, but not Diversity

A new study of re-growing tropical forests has concluded that plant biodiversity takes longer to recover than carbon storage following major disturbances such as clearance for farming.

The findings, published in the scientific journal Proceedings of the Royal Society B, have important implications for conservation since there are now many re-growing forests in South and Central America. The new study is the first large-scale analysis of the recovery of both plant biodiversity and carbon pools in re-growing forests.

Over half of all tropical forests have already been converted for agriculture, logged or burnt in the recent past. Re-growing forests could help both to soak up carbon emissions produced by human activities and to reduce species' extinctions.

The scientists, from the Centre for Ecology & Hydrology and Bournemouth University, concluded that although carbon recovered most quickly, even after 80 years re-growing forests tended to have less carbon than old-growth forests. This is probably because these forests are often dominated by small, fast growing trees. It may take centuries for larger trees which hold more carbon to become established.

In contrast, although the number of tree species recovered relatively rapidly, many species characteristic of old-growth forests were rare in re-growing forests. This is worrying because these species are probably those most vulnerable to extinction.

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Pilot Project to Inject Carbon Dioxide Into Basalt for Sequestration

By early August, scientists will have pumped 1,000 tonnes of pure carbon dioxide into porous rock far below the northwestern United States. The goal is to find a permanent home for the carbon dioxide generated by human activities.

Researchers at the US Department of Energy’s Pacific Northwest National Laboratory (PNNL) in Richland, Washington, began the injections into the Columbia River Basalt formation near the town of Wallula on 17 July. The rock contains pores created as many as 16 million years ago, when magma flowed across what is now the Columbia River Basin. Bubbles of CO2 migrated to the edges of the magma as it cooled, forming layers of holes sandwiched between solid rock (see 'Rock steady').

[...]

The Wallula project is the second of two worldwide to target basalt formations, which scientists hope can hold — and permanently mineralize — vast quantities of gas. In basalt, dissolved CO2 should react with calcium and magnesium to form limestone over the course of decades. Until the gas is locked away, the porous basalt layers are capped by solid rock that will prevent leaking. That should eliminate concerns about leakage that have dogged other proposals to store CO2 deep underground, often in sandstone reservoirs.

The basalt reactions are part of a natural weathering process that has helped to regulate atmospheric CO2 levels throughout geological time. Scientists have analysed mineralization in the lab, but it is only now being tested in the field.

Researchers working on the other basalt project, based in Iceland and run by a consortium of US and European scientists along with Reykjavik Energy, made their first CO2 injections last year and will conduct another round this year. Early results look promising, says Juerg Matter, a geochemist at Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York, who is working on the Iceland project. “The mineralization reaction is most likely faster than what we in the community had thought,” says Matter, who has also contributed to the Wallula project. Assuming that holds true for basalt generally, “you reduce the risk of leakage, and you can pretty much walk away from your storage reservoirs”.

Livermore and UC Santa Cruz Develop Carbon Sequestration Technique In Lab Which Helps De-Acidify Ocean Water

Lawrence Livermore scientists have discovered and demonstrated a new technique to remove and store atmospheric carbon dioxide while generating carbon-negative hydrogen and producing alkalinity, which can be used to offset ocean acidification.

The team demonstrated, at a laboratory scale, a system that uses the acidity normally produced in saline water electrolysis to accelerate silicate mineral dissolution while producing hydrogen fuel and other gases. The resulting electrolyte solution was shown to be significantly elevated in hydroxide concentration that in turn proved strongly absorptive and retentive of atmospheric CO2.

Further, the researchers suggest that the carbonate and bicarbonate produced in the process could be used to mitigate ongoing ocean acidification, similar to how an Alka Seltzer neutralizes excess acid in the stomach.

"We not only found a way to remove and store carbon dioxide from the atmosphere while producing valuable H2, we also suggest that we can help save marine ecosystems with this new technique," said Greg Rau, an LLNL visiting scientist, senior scientist at UC Santa Cruz and lead author of a paper appearing this week (May 27) in the Proceedings of the National Academy of Sciences.

When carbon dioxide is released into the atmosphere, a significant fraction is passively taken up by the ocean forming carbonic acid that makes the ocean more acidic. This acidification has been shown to be harmful to many species of marine life, especially corals and shellfish. By the middle of this century, the globe will likely warm by at least 2 degrees Celsius and the oceans will experience a more than 60 percent increase in acidity relative to pre-industrial levels. The alkaline solution generated by the new process could be added to the ocean to help neutralize this acid and help offset its effects on marine biota. However, further research is needed, the authors said.

"When powered by renewable electricity and consuming globally abundant minerals and saline solutions, such systems at scale might provide a relatively efficient, high-capacity means to consume and store excess atmospheric CO2 as environmentally beneficial seawater bicarbonate or carbonate," Rau said. "But the process also would produce a carbon-negative 'super green' fuel or chemical feedstock in the form of hydrogen."

Most previously described chemical methods of atmospheric carbon dioxide capture and storage are costly, using thermal/mechanical procedures to concentrate molecular CO2 from the air while recycling reagents, a process that is cumbersome, inefficient and expensive.

"Our process avoids most of these issues by not requiring CO2 to be concentrated from air and stored in a molecular form, pointing the way to more cost-effective, environmentally beneficial, and safer air CO2 management with added benefits of renewable hydrogen fuel production and ocean alkalinity addition," Rau said.

Interesting.  Will it scale and deal with real world scenarios?  It almost sounds too good to be true...

Potential for American Biological Carbon Sequestration Increased

A research group has concluded that forests and other terrestrial ecosystems in the lower 48 states can sequester up to 40 percent of the nation’s fossil fuel carbon emissions, a larger amount than previously estimated – unless a drought or other major disturbance occurs.

Widespread droughts, such as those that occurred in 2002 and 2006, can cut the amount of carbon sequestered by about 20 percent, the scientists concluded in a recent study that was supported by the National Science Foundation and U.S. Department of Energy.

The research, published by scientists from 35 institutions in the journal Agricultural and Forest Meteorology, was based on satellite measurements and dozens of environmental observation sites in the AmeriFlux network. Not all of this data had previously been incorporated into earlier estimates, and the new study provides one of the most accurate assessments to date of the nation’s carbon balance.

“With this data it appears that our forests and other vegetation can sequester as much as 40 percent of the carbon emissions in the lower 48 states,” said Beverly Law, a co-author of the study, professor in the Department of Forest Ecosystems and Society at Oregon State University, and science team chair of the AmeriFlux network.

“That’s substantially higher than some previous estimates, which indicated these ecosystems could take up the equivalent of only about 30 percent of emissions or less,” Law said. “There’s still some uncertainty in these data, but it does appear that the terrestrial carbon sink is higher than believed in earlier studies.”

However, the scientists cautioned that major disturbances, such as droughts, wildfires and hurricanes, can all affect the amount of carbon sequestered in a given year. Large droughts that happened twice in the U.S. in the past decade reduced the carbon sink about 20 percent, compared to a normal year.

“With climate change, we may get more extreme or frequent weather events in the future than we had before,” Law said. “About half of the United States was affected by the major droughts in 2002 and 2006, which were unusually severe in their spatial extent and severity. And we’re now learning that this can have significant effects on the amount of carbon sequestered in a given year.”

Carbon dioxide, when released by the burning of fossil fuels, forest fires, or other activities, is a major “greenhouse gas” and factor in global warming. But vegetation, mostly in the form of growing evergreen and deciduous forests, can play an important role in absorbing some of the excess carbon dioxide.

Such information is important to understand global climate issues and develop policies, the researchers noted. This study examined the carbon budget in the U.S. from 2001 to 2006. Also playing a key role in the analysis was the PRISM climate database at OSU, a sophisticated system to monitor weather on a very localized and specific basis.

The period from 2001-06, the researchers noted, had some catastrophic and unusual events, not the least of which was Hurricane Katrina and the massive destruction it caused. It also factored in the 2002 Biscuit Fire in southwest Oregon, one of the largest forest fires in modern U.S. history.

The research found that the temperate forests in the eastern U.S. absorbed carbon mainly because of forest regrowth following the abandonment of agricultural lands, while some areas of the Pacific Northwest assimilated carbon during much of the year because of the region’s mild climate.

Crop lands were not considered in determining the annual magnitude of the U.S. terrestrial carbon sink, because the carbon they absorb each year during growth will be soon released when the crops are harvested or their biomass burned.

The study was led by Jingfeng Xiao, a research assistant professor at the Complex Systems Research Center, Institute for the Study of Earth, Oceans, and Space, at the University of New Hampshire.

Given that the climate would shift would probably cause a lot more droughts, the amount of sequestration is iffy given their own results.

Plankton Blooms Don't Sequester Atmospheric Carbon

Oceanographers Jim Bishop and Todd Wood of the U.S. Department of Energy's Lawrence Berkeley National Laboratory have measured the fate of carbon particles originating in plankton blooms in the Southern Ocean, using data that deep-diving Carbon Explorer floats collected around the clock for well over a year. Their study reveals that most of the carbon from lush plankton blooms never reaches the deep ocean.

The surprising discovery deals a blow to the simplest version of the Iron Hypothesis, whose adherents believe global warming can be slowed or even reversed by fertilizing plankton with iron in regions that are iron-poor but rich in other nutrients like nitrogen, silicon, and phosphorus. The Southern Ocean is one of the most important such regions.

"Just adding iron to the ocean hasn't been demonstrated as a good plan for storing atmospheric carbon," says Bishop, a member of Berkeley Lab's Earth Sciences Division and a professor of Earth and planetary sciences at the University of California at Berkeley. "What counts is the carbon that reaches the deep sea, and a lot of the carbon tied up in plankton blooms appears not to sink very fast or very far."

The reasons, while complex, are most likely due to the seasonal feeding behavior of planktonic animal life, and specifically to the effects of the dark Antarctic winter on plant and animal growth and the mixing of surface and deep waters by winter storms. Phytoplankton blooms in the spring may indicate that much of the zooplankton (animal) population essential for carbon sedimentation has starved during the winter.

The Carbon Explorers involved in the study were launched in January, 2002, as part of the Southern Ocean Iron Experiment (SOFeX), a collaboration led by scientists from Moss Landing Marine Laboratory and the Monterey Bay Aquarium Research Institute. SOFeX was meant to test the Iron Hypothesis in waters between New Zealand and Antarctica during the Antarctic summer. The Berkeley Lab Carbon Explorers were originally intended to monitor the iron-fertilization experiment for 60 days, but they continued to report by satellite throughout the Antarctic fall and winter and on into the following year.

"We would never have made these surprising observations if the autonomous Carbon Explorer floats hadn't been recording data 24 hours a day, seven days a week, at depths down to 800 meters or more, for over a year after the experiment's original iron signature had disappeared," Bishop says.

He explains that "assumptions about the biological pump – the way ocean life circulates carbon – are mostly based on averaging measurements that have been made from ships, at intervals widely separated in time. Cost, not to mention the environment, would have made continuous ship-based observations impossible in this case. Luckily one Carbon Explorer float costs only about as much as a single day of ship time."

Bishop and Wood report their results in a forthcoming issue of the journal Global Biogeochemical Cycles. Preprints are now available to subscribers at http://www.agu.org/journals/gb/papersinpress.shtml.

Woooo! Go Colabbies! That said, if this bares out, this means any plan on using iron seeding is dead in the water.

Where You Grow Biofuels Matters

A new study finds that it will take more than 75 years for the carbon emissions saved through the use of biofuels to compensate for the carbon lost when biofuel plantations are established on forestlands. If the original habitat was peatland, carbon balance would take more than 600 years. The study appears in Conservation Biology.

The oil palm, increasingly used as a source for biofuel, has replaced soybean as the world's most traded oilseed crop. Global production of palm oil has increased exponentially over the past 40 years. In 2006, 85 percent of the global palm-oil crop was produced in Indonesia and Malaysia, countries whose combined annual tropical forest loss is around 20,000 square kilometers.

Conversion of forest to oil palm also results in significant impoverishment of both plant and animal communities. Other tropical crops suitable for biofuel use, like soybean, sugar cane and jatropha, are all likely to have similar impacts on climate and biodiversity.

"Biofuels are a bad deal for forests, wildlife and the climate if they replace tropical rain forests," says research scientist Finn Danielsen, lead author of the study. "In fact, they hasten climate change by removing one of the world's most efficient carbon storage tools, intact tropical rain forests."

As countries strive to meet obligations to reduce carbon emissions under one international agreement (Kyoto Protocol), they may not only fail to meet their obligations under another (Convention on Biological Diversity) but may actually hasten global climate change.

According to the study, reducing deforestation is likely to represent a more effective climate-change mitigation strategy than converting forest for biofuel production, and it may help nations meet their international commitments to reduce biodiversity loss.

Alternatively, planting biofuels on degraded grasslands instead of tropical rain forests would lead to a net removal of carbon from the atmosphere in 10 years. Any biofuel plantations in tropical forest regions should be considered only in former forest land which has already been severely degraded to support only grassy vegetation.

"The EU and the US should only import and subsidize bio-fuel from guaranteed sustainable productions and only from countries which can demonstrate that their forests are sustainably managed," says Danielsen.

In some ways that feels like a "Well, duh, dude." I mean, you cut down the largest carbon sink around and...

A New Method of Carbon Sequestration

New research shows that for millions of years carbon dioxide has been stored safely and naturally in underground water in gas fields saturated with the greenhouse gas. The findings – published in Nature today – bring carbon capture and storage a step closer.

Politicians are committed to cutting levels of atmospheric carbon dioxide to slow climate change. Carbon capture and storage is one approach to cut levels of the gas until cleaner energy sources are developed.

But the risks around the long-term storage of millions of cubic metres of carbon dioxide in depleted gas and oil fields has met with some concern, not least because of the possibility of some of the gas escaping and being released back to the atmosphere. Until now, researchers couldn't be sure how the gas would be securely trapped underground.

Naturally-occurring carbon dioxide can be trapped in two ways. The gas can dissolve in underground water – like bottled sparkling water. It can also react with minerals in rock to form new carbonate minerals, essentially locking away the carbon dioxide underground.

Previous research in this area used computer models to simulate the injection of carbon dioxide into underground reservoirs in gas or oil fields to work out where the gas is likely to be stored. Some models predict that the carbon dioxide would react with rock minerals to form new carbonate minerals, while others suggest that the gas dissolves into the water. Real studies to support either of these predictions have, until now, been missing.

To find out exactly how the carbon dioxide is stored in natural gas fields, an international team of researchers - led by the University of Manchester - uniquely combined two specialised techniques. They measured the ratios of the stable isotopes of carbon dioxide and noble gases like helium and neon in nine gas fields in North America, China and Europe. These gas fields were naturally filled with carbon dioxide thousands or millions of years ago.

They found that underground water is the major carbon dioxide sink in these gas fields and has been for millions of years.

Dr Stuart Gilfillan, the lead researcher who completed the project at the University of Edinburgh said: "We've turned the old technique of using computer models on its head and looked at natural carbon dioxide gas fields which have trapped carbon dioxide for a very long time."

"By combining two techniques, we've been able to identify exactly where the carbon dioxide is being stored for the first time. We already know that oil and gas have been stored safely in oil and gas fields over millions of years. Our study clearly shows that the carbon dioxide has been stored naturally and safely in underground water in these fields."

I have my doubts about carbon sequestration, but I'd like to see some test runs (which I am sure tehy'll do) prior to anything being done.