tagged w/ Anthropogenic Climate Change
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Australia could be totally reliant on solar energy by 2030 if the current obstacles of technical inertia, lack of political will and entrenched interests can be overcome, a leading CSIRO scientist says. ''Australia should be building a solar backbone,'' atmospheric physicist Mike Raupach told a national climate change conference at the Australian National University yesterday.
Pursuing large-scale geosequestration projects to reduce Australia's rising greenhouse emissions was not the answer and ''is fighting against the way the Earth's systems want us to go'', he said.
Dr Raupach, a contributing author to the United Nations Intergovernmental Panel on Climate Change reports, said Australia's greenhouse emissions were growing faster than in any other developed nation in the world, driven by increasing per capita wealth and the ''aggressive consumption'' of the average urban lifestyle.
''We need a cap on total emissions at around 500 billion tonnes of carbon, which means an 80 per cent reduction in emissions for developed countries, and perhaps a 90 per cent reduction for Australia.''
The climate-change threat was ''somewhere between severe and extreme''. A gap was emerging between ''what the economists tells us is possible'' and what scientists insisted was necessary to tackle the problem, Dr Raupach said.
Significant reductions in Australia's greenhouse emissions were ''technically achievable and affordable'', with low-cost mitigation measures including improved refrigeration, lighting, heating and car fuel efficiencies, better building insulation and reduced travel, with carbon offsets invested in renewable energy rather than biosequestration or tree-planting projects, he said. The director of the University of Adelaide's climate research institute, Professor Barry Brook, told the conference that ''to have a reasonable chance'' of avoiding a future increase of 2 degrees of global warming, developed nations must achieve ''at least an 80 per cent reduction in emissions'' by 2050 and begin levelling off emissions ''by no later than 2015''.
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And if Australia can do it, so can the United States.
Australia could be totally reliant on solar energy by 2030 if the current obstacles of... more
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Trees in warm places might be able to shrug off global warming better than those in the UK and colder climes because they contain a remarkable "thermostat" that keeps them the same temperature.
Leaves shed new light on earlier arrival of spring
More proof of global warming?
Greenhouse gases can cause ecological chaos
The temperature inside a healthy tree leaf is affected much less by outside temperature than originally believed, from England to the Caribbean, according to biologists at the University of Pennsylvania.
Researchers found that all tree leaves maintain a near constant temperature
They are concerned that trees in colder regions, such as Britain, could overheat as the climate warms as a result of this hitherto unrecognised mechanism. However, species adapted to warmer climates are likely to take their place.
Surveying 39 tree species ranging in location from subtropical to northerly climates, researchers found a nearly constant temperature in tree leaves.
The conversion of light into chemical energy - photosynthesis - most likely occurs when leaf temperatures are about 21°C, and the outside temperature plays little, if any, role. This means that in colder climates leaf temperatures are elevated and in warmer climates tree leaves cool to keep the temperature just right.
"It is not surprising to think that a polar bear in northern Canada and a black bear in Florida have the same internal body temperature," says Dr Brent Helliker, who reports the work with Suzanna Richter in the journal Nature. "Like us, they generate their own heat.
"However, to think that a black spruce in Canada and a Caribbean Pine in Puerto Rico have the same average leaf temperature is quite astonishing.
"Our research suggests that they use a combination of purely physical phenomena - like the cooling from water evaporation or the warming caused by packing a lot of leaves together - to maintain leaf temperature, a phenomenon we call homeostatisis."
He stresses that this does not mean tree canopies maintain a constant temperature through a day or a season, but rather that this ideal temperature is a long-term target value.
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If true, we then need to be planting more trees in Africa and the Amazon instead of chopping them down. I think this is an interesting find and can lead us to solutions regarding CO2 mitigation.
Trees in warm places might be able to shrug off global warming better than those in... more
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Fourteen research teams studying the impacts of warming on the Arctic Ocean have issued independent projections of how the sea ice will behave this summer, and 11 of them foresee an ice retreat at least as extraordinary as last year’s or even more dramatic. The other three groups that issued a numerical estimate see the ice extent heading back toward, but not equaling, the average minimum for summers since satellites began tracking the comings and goings of Arctic sea ice in 1979. Five other groups chose not to issue a numerical estimate.
The ice assessments, and explanations, can be found on the Web site of the ongoing Study of Environmental Arctic Change, or SEARCH. The initiative was begun following a workshop on Arctic ice trends in March that was triggered by the “drastic and unexpected sea ice decline witnessed in 2007,” according to the report posted online.
This short animation, from NASA’s Scientific Visualization Studio, puts 2007 in perspective:
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Ice melt is the harbinger of climate change. I also think that even more important than observing what melts is what refreezes.
Fourteen research teams studying the impacts of warming on the Arctic Ocean have... more
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In a Hobart laboratory a few weeks ago, a young marine biologist placed the shell of a tiny sea snail on a weighing scale and held her breath. Donna Roberts's critical experiment rested on getting the exact weight of this fragile specimen; any movement in the room could instantly throw off the delicate scale, so sensitive it is called a microbalance.
Roberts had been weighing 100 of these shells, stripped from snails that had been collected from the depths of the great Southern Ocean half way between Tasmania and Antarctica.
The snails, known to biologists as pteropods, swim through the sea like butterflies. They are as abundant as krill and help feed the ocean's huge schools of fish.
The shell specimens dated back to 1996 and the earlier ones had weighed in at 20 micrograms. But Roberts observed that as the specimens became more recent, the weight of the shells had fallen. When her last specimen, from 2005, weighed in at just 10 micrograms, Roberts barely dared to breathe.
"Wow, what is going on?" she asked herself. A halving of shell weight in just one decade was a real worry.
Roberts's still unpublished research is just one reason why her collaborator, Dr Will Howard, from the Antarctic Climate and Ecosystems Cooperative Research Centre, this week convened an extraordinary meeting of Australia's leading marine scientists in Hobart.
For three days, the 50 scientists, along with colleagues from America and New Zealand, focused their collective minds on a threat that has emerged, it seems, from out of the blue: the growing acidification of our oceans.
These scientists now know that burning fossil fuels and massive land clearing are not just warming the planet and raising sea temperatures, they are also changing the chemical make up of the oceans. A vast amount of the carbon dioxide humans have pumped into the atmosphere since the industrial revolution has been absorbed by oceans.
A new report by the Antarctic research centre, released at the Hobart meeting, says that about half the fossil fuel carbon dioxide released into the atmosphere by humans has now dissolved into the oceans. If we keep pumping carbon dioxide into the atmosphere at the current projections, by 2100 the ocean acidification will be three times that experienced at the end of the glacial period, 15,000 years ago.
The chemistry is basic. The ocean is a weakly alkaline solution. When carbon dioxide sucked in from the atmosphere dissolves in sea water, it forms a weak acid, making the ocean more acidic. For sea life with fragile shells, corals and countless other sea creatures, a more acidic ocean could be disastrous and have unknown impacts right up the marine food chain.
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Our oceans have absorbed so much CO2 they will one day no longer be able to sustain life if we continue on the path we are on. What we do to other species we do to ourselves.
In a Hobart laboratory a few weeks ago, a young marine biologist placed the shell of a... more
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The forests of Papua New Guinea are being chopped down so quickly that more than half its trees could be lost by 2021, according to a new satellite study of the region.
The study, by the University of Papua New Guinea and the Australian National University, found that deforestation is much more widespread than was previously thought, even in so-called conservation areas. Papua New Guinea (PNG) has the world's third largest tropical forest, but it was being cleared or degraded at a rate of 362,000 hectares (895,000 acres) a year in 2001, the report said.
Phil Shearman, lead author of the study, said: "The unfortunate reality is that forests in Papua New Guinea are being logged repeatedly and wastefully with little regard for the environmental consequences and with at least the passive complicity of government authorities." The destruction will drive global warming, because tropical forests are an important store of carbon.
The researchers compared satellite images taken over three decades from the early 1970s. In 1972, the country had 38m hectares (94m acres), of rainforest covering 82% of the country. About 15% of that was cleared by 2002.
"For the first time, we have evidence of what's happening in the PNG forests," Shearman said. " The government could make a significant contribution to global efforts to combat climate change. It is in its own interest to do so, as this nation is particularly susceptible to negative effects due to loss of the forest cover."
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WE HAVE TO STOP. We also have to support any tree planting initiative and frankly, I think one should be part of any climate change bill passed in this country.The forests of Papua New Guinea are being chopped down so quickly that more than half... more
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Many physical and ecological systems are being affected by the world's warming climate, researchers say.
Scientists from across the world applied statistical models to published data on changes in 829 physical systems and around 28,800 plant and animal systems —on both global and continental scales — some with data going back to 1970.
Their analysis, published in Nature last week (15 May), looked at whether these changes were related to temperature increase, other factors such as land use change, or simply natural variability.
Around 95 per cent of the physical systems studied responded to the world's warming trend. The analysis found that glaciers in every continent have been shrinking, permafrost is melting, the peak of river levels in spring is shifting, and lake and river temperatures are rising.
And 90 per cent of the changes in plants and animals were consistent with responses to temperature rise, including earlier blooming and leaf unfolding.
The authors found little evidence that natural variability or other environmental factors were significant, and conclude that climate change is affecting these systems.
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It's time to stop debating this and get down to work. Otherwise, we will have nothing to debate over. It will be gone.Many physical and ecological systems are being affected by the world's warming... more
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Peru's Cordillera Blanca, a snow-topped northern mountain range sometimes called the "Peruvian Switzerland," is slowly disappearing because of climate change, a key issue on the table of a Latin America-EU summit being held in Lima this week.
The glaciers making up the range -- declared a natural world heritage site by UNESCO -- have steadily been shrinking, said Marco Zapata, the head of the glaciology unit of Peru's National Institute for Natural Resources.
He explained that between 1948 and 1976, the Cordillera Blanca has diminished by nine meters, and between 1977 and now by around 20 meters.
The time left for tourists to see the spectacular zone is limited, and depends on temperature variations, he said.
Zapata added: "It is known that the shrinking process of the glaciers is irreversible and nothing can be done."
A 1989 evaluation found that Peru had more than 3,000 glaciers in an area of 2,041 square kilometers. Just eight years later, the area had been cut by a quarter, to 1,595 square kilometers.
A clear example of what is happening can be seen on the Pastoruri mountain, a 5,240-meter-high peak that each year attracts 60,000 tourists. "It is turning into an ice-capped mountain, because the snow is rapidly shrinking," Zapata said.
In 1995, the perimeter at the snowline was 1.8 square kilometers. By last year, that had eroded to just 1.1 square kilometers.
Huascaran National Park, where the Cordillera Blanca is situated, contains 663 glaciers including the 6,768-meter-high Huascaran summit itself, along with 296 lakes and 41 rivers.
But Jean Ortiz, who heads the running of the park, said global warming was seriously changing the face of the reserve, where many high-altitude plants and animals were becoming rarer or had disappeared entirely.
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The greatest treasures on this Earth are melting way. Our children will not get to see them. This is so very sad to me. Some days I feel hopeful, and others I feel discouraged. This is one of those days I feel discouraged. It doesnt seem like people on the whole have what it takes to fight this. Too set in our ways, too selfish, too apathetic, too political in our views, with too much wealth and power concentrated in the hands of those who really don't care and actually hope to benefit from it all at the expense of the poor. So the Earth melts while we concern ourselves with the trivialities of our media driven world. Discouraging.Peru's Cordillera Blanca, a snow-topped northern mountain range sometimes called... more
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Climatic changes induced by humans have affected the flora and fauna, along with the physical environment of the world at a much faster pace than previously thought, scientists have said.
A new NASA-led study, noting changes in the physical system, such as glaciers shrinking, permafrost melting and lakes and rivers warming, has linked physical and biological impacts since 1970 with increase in temperatures during that period.
The scientists also noticed changes in biological systems such as leaves unfolding and flowers blooming at a faster pace, birds migrating earlier and plant and animal species moving towards the Earth's poles and higher altitudes.
In addition to global effects, the study also linked climate changes caused by humans with effects on individual continents, particularly North America, Europe and Asia.
The study was based on a database of more than 29,000 data series coming from about 80 studies, with at least 20 years of records between 1970 and 2004.
The team conducted statistical tests and found that patterns of observed impacts correspond with temperature changes around the globe, allowing them to conclude that global impacts are very likely due to human-caused warming.
Climatic changes induced by humans have affected the flora and fauna, along with the... more
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Global warming will threaten the survival of koalas by making the eucalyptus leaves on which they feed toxic, scientists warned on Wednesday.
Australia's most endearing marsupial is already under threat from a severe drought and loss of habitat as housing encroaches on woodland.
But higher temperatures and increased carbon dioxide could shut down their food supply, leaving them to starve to death.
New research shows that the level of toxicity in the leaves of eucalyptus saplings rises, and their nutrient content falls, when they are exposed to higher levels of carbon dioxide.
"What currently may be good koala habitat may well become, over a period of not so many years at the rate that carbon dioxide concentrations are rising, very marginal habitat," said Ian Hume, Emeritus Professor of Biology at Sydney University, who carried out the research.
"I'm sure we'll see koalas disappearing from their current range even though we don't see any change in tree species or structure of the forests."
The koala's ecological niche is precarious enough as it is - eucalyptus leaves have so little nutritional value that the animals have to sleep for 20 hours a day to conserve energy.
The animals are also notoriously fussy eaters - of Australia's more than 600 species of eucalypt trees, koalas will only browse on the leaves of about 25.
The animals would be unable to adapt to the greater toxicity of gum tree leaves, Prof Hume said after presenting his findings at an Academy of Science conference in Canberra. "I don't think they've got enough time to do that, nowhere near enough time to do that," he said.
Global warming will threaten the survival of koalas by making the eucalyptus leaves on... more
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Greenpeace and more than 100 other environmental groups denounced projects for burying industrial greenhouse gases on Monday, exposing splits in the green movement about whether such schemes can slow global warming.
Many governments and some environmental organisations such as the WWF want companies to capture heat-trapping carbon dioxide from the exhausts of power plants and factories and then entomb them in porous rocks as one way to curb climate change.
But Greenpeace issued a 44-page report about the technology entitled "False Hope".
"Carbon capture and storage is a scam. It is the ultimate coal industry pipe dream," said Emily Rochon, climate and energy campaigner at Greenpeace International and author of the report.
Greenpeace and 112 green groups from 21 nations said governments should invest in wind, solar and other renewable energies rather than in capture technologies that would allow coal-fired power plants to stay in operation.
In a statement linked to the report, Greenpeace and allies including Friends of the Earth International said the "false promise" of carbon capture and storage (CCS) "risks locking the world into an energy future that fails to save the climate".
But some other environmental groups accept carbon capture as a way to slow rising temperatures and avert more powerful storms, heatwaves, droughts, disrupted monsoon rains and raised world ocean levels.
"Carbon capture and storage is not an ideal solution, but it buys us time," said Stephan Singer, head of the WWF's European Climate and Energy Programme in Brussels. "We believe it is part of the solution -- an emergency exit."
The UN Climate Panel has said CCS could be one of the main ways for slowing climate change by 2100 -- contributing a bigger share of greenhouse gas cuts than energy efficiency, a shift to renewable energy or a push for nuclear power.
Greenpeace and more than 100 other environmental groups denounced projects for burying... more
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"Scientists have suggested that due to the adverse effects of Arctic ice melting, the hybrid of a polar bear and grizzly bear - dubbed the 'grolar bear', might rise in numbers.
According to a report in The Sun , the effects of climate change means that the hybrid bears could become more common as their habitats increasingly overlap due to global warming.
"One of the real things that is happening is that grizzlies are moving north, at the same time the polar bears are forced to be on the beach and we have found a number of grizzly bear polar bear hybrids," said biologist Dr George Divoky, who has worked in the Arctic region for over three decades.
"Essentially that could mean that it would save the polar bear genes in the grizzly population," he added.
Biologists have already spotted the hybrid species.
In April 2006, a white bear with brown patches was shot in northern Canada and DNA tests confirmed it was a 'grolar' bear. It was said to have been fathered by a male grizzly and a female polar bear.
In spite of the emergence of the hybrid bears, scientists fear that the overall impact of Arctic ice melting could have a disastrous effect in the long run.
"Having seen things, I would never be surprised if in 2008 the summer ice disappears," Dr Divoky said. "This has never happened in the period of human observation. We will know it when it happens and we will have to deal with that," he added. "Scientists have suggested that due to the adverse effects of Arctic ice melting,... more
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Climate change is harder on women in poor countries, where mothers stay in areas hit by drought, deforestation or crop failure as men move to literally greener pastures, a Nobel Peace laureate said on Tuesday.
"Many destructive activities against the environment disproportionately affect women, because most women in the world, and especially in the developing world, are very dependent on primary natural resources: land, forests, waters," said Wangari Maathai of Kenya.
"Women are very immediately affected, and usually women and children can't run away," said Maathai, who won the 2004 Nobel Peace Prize for her work on sustainable development.
"Men can trek and go looking for greener pastures in other areas in other countries ... but for women, they're usually left on site to face the consequences," she said. "So when there is deforestation, when there is drought, when there is crop failure, it is the women and children who are the most adversely affected."
Maathai was in Washington with 1997 Nobel Peace laureate Jody Williams, who got the award for her work in creating an international treaty to ban landmines, and both spoke to reporters at a briefing.
Williams said she saw climate change as a threat to security, and said desertification of former agricultural land fueled the conflict in Darfur.
Credit: Reuters AlertNet.Climate change is harder on women in poor countries, where mothers stay in areas hit... more
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Sierra Club sent letters on Tuesday threatening to file suit to stop construction of eight coal-fired power plants in six states because, the environmental group claims, they violate the Clean Air Act.
"This is the first major ramification on the ground from the (Washington) D.C. circuit kicking out the Bush administration's rules in February," said Bruce Nilles, director of the Sierra Club's effort to stop coal power plants.
In February, a federal appeals court in Washington ruled that the U.S. Environmental Protection Agency violated the Clean Air Act in not setting mandatory cuts for mercury emissions of power plants.
The suits would be filed in the federal districts where the proposed power plants would be located, Nilles said. The suits would seek to require the plants to go back to state permitting agencies for new permits that meet the tougher emission standards, Nilles said.
Coal-fired power plants are the largest source of mercury emissions in the United States as well as 40 percent of U.S. carbon dioxide (CO2) emissions. CO2 is the by far the largest contributor to greenhouse gases that cause global warming.
Coal-fired power plants also are seen by most national politicians as essential because they make half the electricity used in the United States.
The Sierra Club said there are alternatives to coal power plants and that until capturing and sequestering carbon dioxide emissions is proven feasible and affordable, no more coal plants should be built.
Nilles said the Sierra Club has helped stop 63 of the 150 coal-fired power plants that were in the planning stages since 2002, including 31 last year.
Sierra Club sent letters on Tuesday threatening to file suit to stop construction of... more
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In 2005, Hurricane Katrina laid waste to parts of the US Gulf Coast.
Last year, the Arabian peninsula was hit by a super-cyclone, Gonu.
Now, an unusual early-season storm, Nargis, has slammed into Myanmar, brutally changing gear from a Category One to a Category Four cyclone just before it made landfall.
Are these events -- massively costly in lives and treasure -- all linked?
Could they be part of an alarming trend of weird, more powerful storms stoked by global warming?
That's a question that causes fierce jousting among climate scientists.
Experts agree that a single weather event cannot be pinned to climate change, which is part of a long-term pattern spanning decades or centuries.
"It's impossible to say," Adam Lea of the Benfield UCL Hazard Research Centre at University College London told AFP.
"It's only in the long term that you get the perspective that lets you say whether an extreme event is part of a wider trend," said French researcher Herve Le Treut, who contributed to last year's landmark report by the UN's Intergovernmental Panel on Climate Change (IPCC).
But that's where the scientific consensus ends.
Some experts argue the evidence is already hard enough to identify a probable trend: storms are becoming more powerful as global warming heats up the oceans.
One of the most respected voices in the field is that of Massachusetts Institute of Technology (MIT) meteorology professor Kerry Emanuel, who calculates that the power of tropical cyclones has roughly doubled since the 1950s.
In 2005, Hurricane Katrina laid waste to parts of the US Gulf Coast.
Last year, the... more
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Scientists are increasingly confident that both the startling melting seen in the Arctic and the predominant cooling pattern in the Antarctic are being driven by human activity.
In a conference call with reporters Friday, scientists from the National Oceanographic and Atmospheric Administration, Rutgers University and the British Antarctic Survey described new research to be published in Eos, a publication of the American Geophysical Union. In a nutshell:
Natural variability – everything from unusual winds and heat waves to the effects of El Niño, La Niña and other influential global phenomenon – always plays a role in the seasonal melting of sea ice. But the melting seen in the Arctic would not have occurred with natural variability alone; it was the year-on-year erosion of thick, multiyear ice and the gradual warming of the region that has caused a trend in declining sea ice, rather than year-by-year fluctuation.
On Antarctica, the ozone hole is masking the effect of global warming, which otherwise would be causing widespread melting there, said Gareth Marshall, a climatologist with the British Antarctic Survey. The slight but consistent buildup of ice over 30 years was possible because of the way the ozone hole has increased predominantly westerly winds, on average 15%, across the Southern Ocean and Antarctica, effectively blocking warmer air from reaching the continent. The exception is the Antarctic peninsula, which points toward South America, and which has been the site of several high-profile ice shelf collapses.
"At a regional scale, climate change is much more complicated," Marshall said.
Jennifer Francis, a Rutgers atmospheric scientist, called ice "a key vital sign – a visual diagnosis of the climate system."
"All the evidence points to human-made effects playing a role in changes at both poles; evidence to the contrary is very hard to find," Francis said. "This further depletes the arsenal that human-caused climate change is nothing to worry about."
James Overland, a NOAA oceanographer, counted himself a global warming skeptic only a few years ago, but now describes himself as "startled" by the changes occurring in the Arctic, and the strong evidence he sees in climate models.
Scientists are increasingly confident that both the startling melting seen in the... more
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Before humans began burning fossil fuels, there was an eons-long balance between carbon dioxide emissions and Earth's ability to absorb them, but now the planet can't keep up, scientists said on Sunday.
The finding, reported in the journal Nature Geoscience, relies on ancient Antarctic ice bubbles that contain air samples going back 610,000 years.
Climate scientists for the last 25 years or so have suggested that some kind of natural mechanism regulates our planet's temperature and the level of carbon dioxide in the atmosphere. Those sceptical about human influence on global warming point to this as the cause for recent climate change.
This research is likely the first observable evidence for this natural mechanism.
This mechanism, known as "feedback," has been thrown out of whack by a steep rise in carbon dioxide emissions from the burning of coal and petroleum for the last 200 years or so, said Richard Zeebe, a co-author of the report.
"These feedbacks operate so slowly that they will not help us in terms of climate change ... that we're going to see in the next several hundred years," Zeebe said by telephone from the University of Hawaii. "Right now we have put the system entirely out of equilibrium."
In the ancient past, excess carbon dioxide came mostly from volcanoes, which spewed very little of the chemical compared to what humans activities do now, but it still had to be addressed.
This antique excess carbon dioxide -- a powerful greenhouse gas -- was removed from the atmosphere through the weathering of mountains, which take in the chemical. In the end, it was washed downhill into oceans and buried in deep sea sediments, Zeebe said.
14,000 TIMES FASTER THAN NATURE
Zeebe analysed carbon dioxide that had been captured in Antarctic ice, and by figuring out how much carbon dioxide was in the atmosphere at various points in time, he and his co-author determined that it waxed and waned along with the world's temperature.
"When the carbon dioxide was low, the temperature was low, and we had an ice age," he said. And while Earth's temperature fell during ice ages and rose during so-called interglacial periods between them, the planet's mean temperature has been going slowly down for about 600,000 years.
The average change in the amount of atmospheric carbon dioxide over the last 600,000 years has been just 22 parts per million by volume, Zeebe said, which means that 22 molecules of carbon dioxide were added to, or removed from, every million molecules of air.
Since the Industrial Revolution began in the 18th century, ushering in the widespread human use of fossil fuels, the amount of carbon dioxide in the atmosphere has risen by 100 parts per million.
That means human activities are putting carbon dioxide into the atmosphere about 14,000 times as fast as natural processes do, Zeebe said.
And it appears to be speeding up: the US government reported last week that in 2007 alone, atmospheric carbon dioxide increased by 2.4 parts per million.
The natural mechanism will eventually absorb the excess carbon dioxide, Zeebe said, but not for hundreds of thousands of years.
"This is a time period that we can hardly imagine," he said. "They are way too slow to help us to restore the balance that we have now basically distorted in a very short period of time."
Before humans began burning fossil fuels, there was an eons-long balance between... more
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Ice cores are essential for climate research, because they represent the only archive which allows direct measurements of atmospheric composition and greenhouse gas concentrations in the past. Using novel isotopic studies, scientists from the European Project for Ice Coring In Antarctica (EPICA) were now able to identify the most important processes responsible for changes in natural methane concentrations over the transition from the last ice age into our warm period. The study now published in the scientific magazine nature shows that wetland regions emitted significantly less methane during glacial times. In contrast methane emissions by forest fire activity remained surprisingly constant from glacial to interglacial times.
In the current issue of Nature, members of the EPICA team publish new insights into natural changes in the atmospheric concentrations of the second most important greenhouse gas methane (CH4). The scientists present the first glacial/interglacial record of the carbon isotopic composition of methane (δ13CH4) providing essential information on the sources being responsible for the observed CH4 concentration changes.
The well known glacial/interglacial changes in atmospheric methane concentrations are quite drastic. Glacial concentration were on average 350 ppbv (part per billion by volume) and increased to approximately 700 ppbv during the last glacial/interglacial transition superimposed by rapid shifts of about 200 ppbv connected to rapid climate changes. During the last centuries human methane emissions artificially increased CH4 concentrations to approximately 1750 ppbv.
Ice cores are essential for climate research, because they represent the only archive... more
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Satellite images on this interactive map show how the Gulf Stream is currently under threat.Satellite images on this interactive map show how the Gulf Stream is currently under... more
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The map tells the story. Climate change is here./////Excerpt:by Staff Writers/////
New York NY (SPX) Jan 17, 2008/////
Climatologists at the NASA Goddard Institute for Space Studies (GISS) in New York City have found that 2007 tied with 1998 for Earth's second warmest year in a century. Goddard Institute researchers used temperature data from weather stations on land, satellite measurements of sea ice temperature since 1982 and data from ships for earlier years.
The greatest warming in 2007 occurred in the Arctic, and neighboring high latitude regions. Global warming has a larger affect in polar areas, as the loss of snow and ice leads to more open water, which absorbs more sunlight and warmth. Snow and ice reflect sunlight; when they disappear, so too does their ability to deflect warming rays. The large Arctic warm anomaly of 2007 is consistent with observations of record low geographic extent of Arctic sea ice in September 2007./////
"As we predicted last year, 2007 was warmer than 2006, continuing the strong warming trend of the past 30 years that has been confidently attributed to the effect of increasing human-made greenhouse gases," said James Hansen, director of NASA GISS./////
"It is unlikely that 2008 will be a year with truly exceptional global mean temperature," said Hansen. "Barring a large volcanic eruption, a record global temperature clearly exceeding that of 2005 can be expected within the next few years, at the time of the next El Nino, because of the background warming trend attributable to continuing increases of greenhouse gases."/////
The eight warmest years in the GISS record have all occurred since 1998, and the 14 warmest years in the record have all occurred since 1990.////End of excerpt////
The map tells the story. Climate change is here./////Excerpt:by Staff Writers/////... more
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And this is only from January to September of this year. Puts it all in perspective doesn't it?And this is only from January to September of this year. Puts it all in perspective... more
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