What the work means for the carbon balance of the Earth is also not as obvious as it may seem.
Recently, it was shown that old forests continue to suck away carbon into their third centuries and beyond2.
With fewer live trees, you would expect that they would take up less carbon suggests Kurz.
or long-lived wood products to keep the carbon from the atmosphere, and then replanting with species that are suited slightly more to the changing climate.
The new legislation aims make the approval of these compounds more uniform throughout Europe There was also growing public concern that the existing system lets through pesticides that endanger people's health.
including injecting aerosol particles into the stratosphere and increasing the reflectivity of clouds over the ocean.
This kind of approach will be at best a minor niche player in our overall response to the climate-carbon problem.
even while being adamant that they cannot replace the imperative need to cut carbon emissions.
if true, the finding would require a major rethink of the planet's carbon budget. But the claim has proved controversial.
The best way for the current generation to help posterity might be through reducing carbon emissions;
but also fiscal policies and regulations and the most important is, of course, a price on carbon. Whether it is a tax
Rainforest loss in Xishuangbanna also has implications for carbon dynamics and climate change in the region.
and his colleagues have calculated that 6 million tonnes of biomass carbon stock were lost in the prefecture between 1976 and 20031.
are exploring the potential of carbon trading and biodiversity offsets to help conserve the land
Nature Newsthe climate community is counting the costs of losing NASA's Orbiting Carbon Observatory (OCO),
and identify'carbon sinks'around the globe. Many also hoped that OCO would pioneer an approach for monitoring greenhouse gas emissions under a future Kyoto-style global warming treaty.
a senior scientist who studies carbon and nitrogen cycles at the National Center for Atmospheric Research in Boulder,
if the international community implements carbon regulations that require each country to accurately assess its carbon emissions.
The proposed A-SCOPE (Advanced Space Carbon and Climate Observation of Planet Earth) would use a laser to actively probe the CO2 in the atmosphere.
These defences target a specific molecule produced by the fungus, and in time, the fungus often evolves a way to modify the molecule,
or to go without it entirely. Increasingly, breeders are turning to a class of defence gene with a broader spectrum of resistance.
The gene encodes a protein that is similar to molecular transporters that have been implicated in drug resistance.
decreasing the amount of carbon that plants remove from the atmosphere further exacerbating greenhouse warming by carbon dioxide.
and release huge amounts of carbon each year. On the whole, they are a significant'sink'for atmospheric carbon dioxide,
they could turn into a carbon'source'sooner than we thought. So, are we in danger of losing our closest allies in the fight against climate change?
the unusual 2005 drought there has turned apparently some of the affected areas of the Amazon from a carbon sink to a carbon source.
and after the drought revealed that forest patches subjected to a 100-milimetre decrease in rainfall released on average 5. 3 tonnes of carbon per hectare as trees in the area died.
Basin-wide, between 1. 2 billion and 1. 6 billion tonnes of carbon were released as a result of the intense dry season and weakened wet season during 2005, the team estimates.
So does climate change mean that rainforests will not be carbon sinks in the future? That's not clear,
How large a carbon sink are the world's tropical forests at the moment? Scientists estimate that mature tropical forests,
take up as much as 1. 3 billion tonnes of carbon per year. This is a substantial amount, equivalent to almost 20%of carbon emissions from fossil-fuel burning.
Tropical forest thus accounts for around 40%of the global terrestrial carbon sink. The good news is undisturbed that old forests keep getting better at sequestering carbon from the atmosphere.
Over the past couple of decades, mature tropical forests in Africa and South america seem to have taken up an extra 0. 6 tonnes of carbon per hectare each year on average2
3. Tropical forests in Asia are likely to have improved their carbon uptake as well, although probably at a lower rate.
How reliable are these figures? Measuring tree growth is notoriously difficult, not least because tropical observation networks are pitifully few, particularly in Africa.
Problems related to plot selection, comparability and converting tree-diameter measurements to carbon content have led to an intense debate about the size and fate of the tropical (and global) terrestrial carbon sink.
Given the many uncertainties, forests have been excluded from national carbon budgets under the 1997 Kyoto Protocol on Climate Change.
However, data gathered over the past decade suggest that undisturbed old-growth forests in and outside the tropics do indeed continue to grow
and accumulate carbon. There is little doubt that tropical forests have acted as a substantial carbon sink for at least the past couple of decades.
Old-growth boreal forests which were suspected long to be carbon-neutral, have recently been found to keep accumulating carbon as well4.
How long will old forests continue to get better at taking up CO2? That is a key question.
Deforestation and forest degradation, through logging, clearing and fire, are only the most obvious problems.
So when putting a carbon value on them we'd rather be conservative.
Evidence for ancient horse ranch uncovered: Nature Newshumans rode and milked horses as early as 3500 BC,
the team analysed the hydrogen isotope ratios of fat residue in pottery shards and found two distinct signatures that seemed to correspond to horse carcass fat and mare's milk.
The California Air Resources Board approved its'low-carbon fuel standard'on 23 april, requiring fuel providers to cut the greenhouse-gas emissions from fuels by 10%by 2020,
but the low-carbon fuel standard is exactly the right approach. The US Environmental protection agency is reviewing its own ruling that will establish greenhouse-gas criteria under the national biofuels mandate.
The low-carbon fuel standard could also prove a barrier to coal-based fuels, while providing a boost to vehicles powered by natural gas and electricity.
At the moment developing countries don't really contribute much in terms of carbon. We need to identify the particular things we can do to make sure that we don't limit those countries'growth
but at the same time ensure that growth can be minimized carbon. What sort of research will DFID's health programme support?
Nature Newsforestry experts have warned again that climate change could transform forests from sinks to sources of carbon.
The carbon storing capacity of global forests could be lost entirely if the earth heats up 2. 5 °Celsius above preindustrial levels, according to a new report1.
The impacts of these fires and pest infestations will lead to an additional release of carbon into the atmosphere,
This would lead to more carbon being released a recent report in Science2 found that a 2005 drought in the Amazon basin released about 1. 2 billion-1. 6 billion tonnes of carbon (See'Climate change crisis for rainforests'.
By 2020, the projected end of the outbreak, about 270 megatonnes of carbon will have been emitted to the atmosphere3.
Nature Newssince the Orbiting Carbon Observatory (OCO) crashed into the ocean minutes after its 24 february launch,
Or fund ground and suborbital carbon measurements, while working with existing greenhouse-gas monitoring satellites such as Europe's Envisat and Japan's Greenhouse gases Observing Satellite (GOSAT, also known as IBUKI).
The case against reincarnating OCO is that the spectroscopy it used to measure carbon levels needed reflected sunlight to work,
and some states are hoping that a market for carbon credits based on retaining forests will make them money.
The state's'low carbon fuel standard''adopted last month, sets a greenhouse-gas standard for fuels
However, there are proposals to deploy something like California's low carbon fuel standard at the national level.
or molecular sodium both in the plumes and in one of Saturn's rings thought to be fed by these plumes, the E ring.
One of these suggests that reservoirs of clathrates gassy molecules locked up in the lattice of another molecule exist below the surface.
which carry up ice particles with them to form the icy plumes. These ice particles could carry up salt as well
says Susan Kieffer a geologist at the University of Illinois at Urbana-Champaign. Sodium isn't the proof of a liquid ocean,
where more carbon is bound up in plants and soil. Areas that are protected not formally, and thus are most likely to be cleared in the future,
contain roughly 25 percent more carbon than areas cleared in 2001, according to the study. 1the arc of deforestation started out in the southeast,
which is responsible for upward of 20 percent of global carbon emissions. Asner says the study serves as a reminder that monitoring forest cover will not be enough in the future.
what scientists know about both forest carbon and the drivers of deforestation. It makes perfect sense,
the results were published in Global Change Biology. 2 It basically provided a benchmark map of the biomass carbon in the Amazon,
China bases its assessment of historical emissions on the idea of a per-capita carbon budget for carbon emissions from 1850 to 2050, in which cumulative emissions,
I countries reduce their current carbon emissions they will still have exceeded their per-capita allocation.
The researchers tracked how much of each flour the beetles had consumed by looking at the ratio of carbon-13 to carbon-12 in ground-up beetle carcasses.
Wheat and maize have different ratios of these carbon isotopes. After only two weeks, Agashe found, the beetles'diet shifted to almost 30%maize flour.
The authors outline several ways of reducing carbon emissions while limiting energy sprawl. These include energy conservation to reduce the need for additional energy and land use;
and a flexible cap-and-trade system that allows for offsets that would provide incentives for low-carbon-emitting activities.
producing electricity and a range of nuclear isotopes, including plutonium. Iran denies that the reactor has a military purpose.
Isotope shortage: A nuclear reactor in Petten, The netherlands, that supplies radioactive isotopes for use in medical imaging reopened last week after a month's scheduled maintenance partly alleviating a global shortage of the isotopes (see Nature 460,312-313;
2009). ) But the reactor is due to shut down again next March for six months of repairs.
Canada's Chalk River, Ontario, reactor whose closure precipitated the isotope crisis will not reopen until 2010.
Julia Bailey-Serres, a molecular geneticist at the University of California, Riverside, says that the Submergence
Nature Newsthe health of the world's forests and their capacity to lock away carbon could be jeopardized by logging
So even though the region could lose a lot of biodiversity and a large proportion of its carbon stock,
which hold the most carbon. In a case study of an evergreen forest in Cambodia, Sasaki and his co-author Francis Putz from the University of Florida in Gainsville use inventory data for plots of trees with trunks wider than 5 centimetres to estimate that the forest
holds 121.2 tonnes of carbon per hectare. Of this, 71.4 tonnes is in trees that have trunks wider than 45 centimetres the trees that loggers are most likely to target.
the carbon stock would be depleted by almost 40, %yet the forest would still be considered a forest under the UNFCCC definition,
and estimate the forest's carbon stock. Burgess says Sasaki's paper has not proven why its proposed definition of a forest would be optimal,
so the more carbon it is retaining. Working out the amount of degradation that would be tolerable in a post-Kyoto agreement would be useful.
That is 75%less than the going price on the European carbon market. Backed by a satellite monitoring system and an increasingly focused enforcement programme
Climate negotiators in the United nations talks are looking at various ways to link international carbon markets to forest conservation,
cio Lula da Silva urging the country to reconsider its opposition to directly tapping carbon markets for forest conservation.
suggesting that carbon markets could surpass $2 trillion annually by 2020 and $15 trillion in 2050.
With global temperatures rising as a result of climate change, the emission of methane which traps about 25 times more of the Sun's heat than carbon dioxide will play a greater part in the global carbon budget than it does now
but the lack of an accurate estimate of the baseline level challenges the use of paddy emissions in carbon trading,
Mystery of missing carbon cracked: Nature Newsmysteriously, Earth has much less carbon in its rocks than would be expected from the amounts of carbon available in the planet-forming regions of our Galaxy.
But a new model suggests that chemical reactions between carbon grains and oxygen could be the explanation.
Planets form from the disks of gas and dust that coalesce around stars. The gas and dust in these disks make up the interstellar medium that forms the space between stars in galaxies,
with the dust containing carbon-rich and silicate-rich grains. But despite the green, carbon-rich surface of our planet
Earth's mantle is remarkably poor in carbon compared with the amount in the interstellar medium.
Meteorites, thought to be the building blocks of our planet, also have missing carbon, whereas comets,
which are formed farther away from the Sun, do not. Conversely, silicon seems to make it from the interstellar medium, from
Astronomers have struggled to fully account for the carbon shortfall in Earth's mantle and in meteorites.
Now Ted Bergin at the University of Michigan, Ann arbor, has come up with a model that could explain what happened to the carbon.
Previous theories to explain why all the interstellar-medium carbon didn't make it into the material that formed Earth include the evaporation of primordial carbon-rich grains from the disk.
although nowhere near as hot as the 1, 200 kelvin needed to evaporate carbon. Here, oxygen atoms exist,
he says, that react with the tiny carbon grains but not with silicates. These grains are about one-tenth of a micrometre in diameter.
Because of this reaction, the middle part of the disk, where planets are formed, would become depleted in carbon.
The reaction is oxygen hitting the carbon grain and sputtering carbon off says Bergin. And this can happen at around 500 kelvin,
he says. Farther out from the heat source, the reaction between oxygen and carbon would have been much slower,
which explains why planets such as Mars don't seem to have the carbon deficit. Mike Jura at the University of California, Los angeles, says that the model is very plausible.
In random scoops of interstellar matter one would expect a lot of carbon, he says. Jura agrees that the model suggesting evaporation of carbon is flawed,
We're nowhere near 1, 200 kelvin. That takes a lot of heating he says. Bergin's chemical model helps to take away the need for that heat,
he says. If the new model is correct, one would expect to see lots of extra carbon in the gassy part of the disk from which planets are formed.
He's now working out how this carbon might be detected astronomically, and hopes eventually to be able to test this.
And all the extra gas-phase carbon that the model releases might have helped life to form,
Jura suggests. It's abundantly clear that if the Earth had got all of the carbon that was available,
I guess that would have presented a bit of a problem for forming life, Bergin says. We would have had way too much of a greenhouse
Many maize varieties already contain a gene to make this compound. But most of the varieties that have emerged from commercial selective breeding particularly in North america have lost the ability to express it.
The main problem is that researchers don't know the key compounds to target in most plants.
His team's next step is to work out ways of making plants emit the compound only when under attack by pests.
and production from a possible carbon fertilization effect increased carbon dioxide levels in the atmosphere may be beneficial to some crops,
Taking carbon fertilization into account could give a more optimistic outcome, he says. But Goulding adds that the models also do not include loss of land to bioenergy crops
Carbon market confusion: The European commission exceeded its authority in imposing tighter-than-requested caps for greenhouse-gas emissions on Poland and Estonia in the second period of the Emission Trading System, a court ruled last week.
The price of carbon credits fell following the news, because traders thought the commission might have to grant additional allowances to Poland,
however and its long-term effect on European carbon emissions is unclear. Events Thousands of students
A123systems, which makes rechargeable lithium-ion batteries, raised US$380 million at $13. 50 a share at its initial public offering,
The compound is more stable than the lithium metal oxides used in today's laptops and mobile phones,
The compound is used to fumigate soils, and is a replacement for methyl bromide a chemical that has been found to eat away at the ozone layer,
& the Press News maker Large Hadron Collider Physicists last week injected particles into the accelerator for the first time
Tomasini says that one alternative would be to identify the services provided by forests, such as carbon sequestration,
Business watch In September, French company Arkema became the latest carbon-nanotube manufacturer this year to announce plans for a drastic scaling up of production.
Despite the materials'present reliance on the mixed fortunes of the automobile industry, the market for carbon nanotubes as raw materials looks set to grow rapidly.
Carbon cuts: Carbon dioxide emissions could fall by 3%worldwide this year because of the global economic crisis,
and how to regulate carbon trading largely unanswered. Who is running the show? And where do we go from here?
and to a lesser extent the natural-gas industry, see opportunities in the push toward low-carbon energy. Similarly, major companies such as The Dow chemical Company and General electric are pushing for legislation as part of the US Climate Action Partnership.
a molecular biologist who studies maize at Stanford university in Palo alto, California, and is an author of one of the Public library of Science Genetics papers3.
Australia's national science agency has sought to defuse accusations that it is gagging scientists by allowing the publication, after some rewording, of a paper critical of the effectiveness of cap-and-trade schemes in controlling carbon emissions.
Carbon cutters: Brazil has pledged to reduce its projected carbon dioxide emissions in 2020 by 36-39%below business-as usual levels, increasing pressure on other countries less than a month before the United nations climate summit in Copenhagen.
Business watch One of the questions facing climate negotiators in Copenhagen next month is how to handle surplus carbon allowances in Russia
The Oslo-based consultancy Point Carbon projects that surplus carbon allowances will add up to the equivalent of 9 billion tonnes of carbon dioxide during the period 2008-12.
Point Carbon also analysed a 2013-20 scenario that takes into account the economic downturn and current commitments by developed countries.
or by soil adsorption that takes the compounds out of solution. That's the sticking point, he says.
Yeakel analysed the ratios of carbon isotopes in the lions'tissues, which should reflect the isotope ratios of their prey.
Browsing animals, such as giraffes and antelopes, have different ratios of carbon isotopes to grazers because their food shrubs and trees versus grasses carries out different types of photosynthesis. The team characterized the humans'isotope ratios by taking advantage of a fluke of history,
says team leader Nathaniel Dominy, also at the University of California, Santa cruz. In the early twentieth century,
an archaeologist took more than 100 Taita skulls from Kenyan shrines and shipped them to England.
and found that the Taita's ratio of nitrogen isotopes was distinct from the herbivores.
which prey combinations were most likely to produce the lions'isotope ratios. The results show that for most of their lives,
Extrapolating from their isotope ratios, the authors conclude that, over the 9 month period, the lions probably consumed around 10.5 and 24. 2 humans, respectively,
The different prey possibilities have similar isotope ratios, he says. As a result, a wide range of proportions of available prey items could account for the lions'isotope ratios,
including many or no people, even during the period before they became maneaters. Yeakel acknowledges that there are many possible combinations the model shows that humans could have made up 4-56%of the dominant maneater's diet
Developing countries are focusing on policies to reduce emissions growth and set up low-carbon development.
The government is also rethinking its position on the role of forest carbon in a future climate treaty.
cio Lula da Silva appointed a task force to study the issue after nine governors representing Amazon states urged him in June to reconsider Brazil's policy on carbon markets,
That panel has proposed allowing nations to offset up to 10%of their commitment by purchasing carbon credits for avoided deforestation.
and characterize them at a molecular level (see'Last Chance Clinic').'Massagee, whose symptoms hinted at a novel condition involving genes that control muscle formation,
Orbiting Carbon Observatory plan re-emerges after splashdown On 24 february a payload shroud stayed stuck to a Taurus booster rocket,
and NASA's US$280 million Orbiting Carbon Observatory (OCO) crashed into the sea, dashing the hopes of scientists who wanted to use the satellite to measure sources
and the carbon they contain. But just how much carbon is at stake? Researchers at the meeting have given their best answer yet:
the first satellite-based estimates of the biomass contained in the world's tropical forests. Current biomass estimates for the tropics are gathered based on data by the Food and agriculture organization of the united nations (FAO),
recently estimated to be around 15%of global carbon emissions (G r. van der Werf et al. Nature Geosci. 2, 737-738;
and other scientists to estimate how much carbon is locked within trees, vegetation and soils on a given patch of land rather than relying on rough averages that are calculated across a forest.
Sassan Saatchi, an environmental scientist at NASA's Jet propulsion laboratory in Pasadena, California, worked on one study with researchers at the carbon consulting firm Winrock International in Arlington, Virginia.
South america comes in with about 145 gigatonnes of carbon in vegetation and soils about 26%higher than what has been reported by the Intergovernmental Panel on Climate Change (IPCC.
a geographer at the World bank in WASHINGTON DC, is to produce better estimates for carbon emissions from deforestation.
if forests are going to be linked to international carbon markets. The new pantropical biomass maps from Saatchi and Woods Hole won't accomplish that goal,
but they can provide scientists and policy-makers with a better understanding of carbon trends. For example
Carbon targets: Following a similar announcement by China, India said it would cut its carbon intensity the amount of carbon dioxide emitted relative to economic output by 20-25%from 2005 levels by 2020.
Environment minister Jairam Ramesh, announcing the commitment on 3 december, said that the target was worked out in concert with other developing countries (see Nature 462,550;
Australia's government has for the second time rejected proposed legislation to create a carbon-trading scheme.
Market watch Amazonian nations will be the early winners in any market for forest carbon credits,
The Forest Carbon Index, released by the environmental think tank Resources for the Future and consultancy firm Climate Advisers, both based in WASHINGTON DC, charts where governments should invest in preserving forests in developing countries.
The report says that 85%of the best places for early forest carbon returns (2013-20) are in the greater Amazon
Australia's national science agency has been accused of trying to alter a peer-reviewed paper that was critical of carbon-trading schemes,
Amazon is best site for forest carbon investments: Nature Newsamazon nations will be the early winners in a future market for forest carbon credits,
which could grow to US$20 billion annually by 2020, according to a new report. It is estimated that deforestation accounts for around 12%of the greenhouse-gas emissions that cause climate change1
The Forest Carbon Index, released by the environmental think tank Resources for the Future and consultancy firm Climate Advisers, both based in WASHINGTON DC, aims to help investors
The index is calculated based on an area's biological potential to store carbon and the local opportunity costs of protecting forests rather than cutting them down for timber,
It's the first study of its kind to display the best places to enter the forest carbon market in such a comprehensive way,
According to the study, the Amazon-Andes, Central america, the Congo Basin, Madagascar and Southeast asia are all experiencing enough deforestation to capitalize on the carbon market.
The report suggests that 85%of the best places for forest carbon returns are in the greater Amazon
The Congo Basin with its carbon-rich forests and rock-bottom prices contains around 75%of the potentially high-profit locations.
But relatively low deforestation rates, political instability and lack of capacity to bring carbon credits to market mean that the region is unlikely to garner much investment in the next decade.
because it wants developed nations to concentrate on reducing their own carbon emissions (although this position may soften in the Copenhagen talks,
'says that although the index is a good overview of forest carbon opportunities, some of the global and national datasets used should be treated with caution.
Areas that are identified currently in the Congo Basin as low cost forest carbon may actually lie over valuable mineral concessions
head of forest services at carbon-trading company Ecosecurities, based in Dublin, Ireland. Fehse would like the index to be expanded to track progress in developing policy,
legal and social systems for the carbon market in the years to come. As layers of information are added,
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