Archive for ‘CO2’

12

Shorter Lived Climate Forcers: Agriculture Sector and Land Clearing for Livestock

Wednesday, August 10th, 2011

In this video presentation, Gerard Wedderburn-Bisshop, World Preservation Foundation Senior Scientist, puts forward the case for how, with the devastating effects of climate change being felt ever-more quickly and with increasing intensity, the importance of embracing fast-acting solutions to mitigate climate change has increased dramatically.

In recent years, greater understanding of climate science has advanced considerably, and scientists and even policy makers now recognise that climate change in the short term is being driven by extremely potent, shorter-lived climate forcers. By reducing these climate forcers — namely black carbon, methane and tropospheric ozone — cooling begins rapidly.

Globally, the production of meat and dairy are significant contributors of these fast warming agents with far reaching consequences on planetary warming and environmental devastation. These include the major effects of black carbon due to biomass burning, on West Antarctica as well as the tropical monsoons; deforestation; soil carbon loss; and, food and water security. It’s estimated that 47% to 60% of the black carbon reaching West Antarctica and causing rapid melting is due to biomass burning resulting from livestock pasture management.

CO2 from pasture maintenance fires, reforestation of pastures and soil carbon uptake on relief of grazing pressure may also play a part in a fast-acting solution to the climate crisis.

This video is a synopsis of the paper Gerard wrote that examines the contributions of agriculture, namely livestock farming, to planetary warming through the shorter-lived climate forcers, and the effect of animal agriculture abatement on alleviating global warming and environmental collapse. We also propose four policy measures to immediately reduce the shorter-lived warming agents.

(By: Gerard Wedderburn-Bisshop: Senior Scientist, World Preservation Foundation )

Afforestation will hardly dent warming problem: study

Sunday, June 19th, 2011

Schemes to convert croplands or marginal lands to forests will make almost no inroads against global warming this century, a scientific study published on Sunday said.

Afforestation is being encouraged under the UN’s Kyoto Protocol climate-change treaty under the theory that forests are “sinks” that soak up carbon dioxide (CO2) from the air through photosynthesis.

But environmental researchers, in a new probe, said that even massive conversion of land to forestry would have only a slender benefit against the greenhouse-gas problem.

This is partly because forests take decades to mature and CO2 is a long-lasting molecule, able to lurk for centuries in the atmosphere.

But another reason is that forests, even as they absorb greenhouse gas, are darker than croplands and thus absorb more solar heat — and in high latitudes, this may even result in net warming.

Vivek Arora of the University of Victoria in British Columbia and Alvaro Montenegro of St. Francis Xavier University in Nova Scotia modelled five scenarios in which afforestation was carried out over 50 years, from 2011 to 2060.

They used a Canadian programme called CanESM1 that simulated the impacts on land, sea and air if Earth’s surface temperature rose by some 3.0 degrees Celsius (5.4 degrees Fahrenheit) by 2100 compared to 1850.

Even if all the cropland in the world were afforested, this would reduce the warming by only 0.45 C (0.81 F) by a timescale of 2081-2100, according to the study, which appears in the journal Nature Geoscience.

Fifty-percent afforestation would brake it by an even tinier 0.25 C (0.45 F).

Both scenarios are, of course, wildly unrealistic because of the need to grow food.

Fifty-percent afforestation would require at least a doubling in crop yield to feed the human population because half of the crop area would be taken out of use.

The other three scenarios found that afforestation in the tropics was three times more efficient at “avoided warming” than in northerly latitudes and temperate regions.

The study said that afforestation does have other benefits, for the economy and the ecoystem.

“There’s nothing wrong with afforestation, it is positive, but our findings say that it’s not a response to temperature control if we are going to be emitting (greenhouse gases) this way,” Montenegro told AFP.

The study said bluntly, “Afforestation is not a substitute for reduced greenhouse-gas emissions.”

In forest programmes, policymakers would be advised to focus afforestation efforts in the tropics but also push hard against deforestation, which accounts for 10 to 20 percent of greenhouse-gas emissions globally.

Avoiding deforestation is under discussion for post-2012 climate action under the UN flag.

Source: Afforestation will hardly dent warming problem: study – Physorg

Date: 19 June 2011

Curb soot and smog to keep Earth cool, says UN

Tuesday, June 14th, 2011

Sharply reducing emissions of soot and smog could play a critical role in preventing Earth from overheating, according to a UN report released on Tuesday.

Curbing these pollutants could also boost global food output and save millions of lives lost to heart and lung disease, said the report from the UN Environment Programme (UNEP) and the World Meteorological Organisation (WMO).

Even as climate talks remain deadlocked on how to share out the task of cutting CO2, parallel action on “black carbon” particles and ground-level ozone would buy precious time in the quest to limit global temperature rise to 2.0 degrees Celsius (3.6 degrees Fahrenheit), it said.

Record output in 2010 of carbon from energy use and unprecedented CO2 levels in the atmosphere suggest that efforts to maintain the 2.0 C cap, widely seen as a threshold for dangerous warming, may already be doomed, say scientists.

On current trajectories, temperatures are set to go up 1.3 C (2.3 F) — on top of the 0.9 C (1.6 F) jump since human-induced warming kicked in — by 2050, bringing the total compared to preindustrial levels to 2.2 C (4.0 F).

But quickly tackling black carbon and smog-related ozone could slash 0.5 C (0.9 F) off the temperature increase projected for 2030, putting the two-degree target back on track, the new findings suggest.

“There are clear and concrete measures that can be undertaken to help protect the global climate in the short and medium term,” said Drew Shindell, a researcher at NASA’s Goddard Institute for Space Studies and one of the 50 scientists behind the new assessment.

“The win-win here for limiting climate change and improving air quality is self-evident and the ways to achieve it have become far clearer.”

The report was unveiled in Bonn as delegates from more than 190 nations under the UN Framework Convention on Climate Change (UNFCCC) struggle to make headway in the deeply stymied negotiations.

Black carbon, found in soot, is a byproduct of incomplete burning of fossil fuels, wood and biomass, such as animal waste. The most common sources are car and truck emissions, primitive cook stoves, forest fires and industry.

Soot suspended in the air accelerates global warming by absorbing sunlight. When it covers snow and ice, white surfaces that normally reflect the Sun’s radiative force back into space soak up heat instead, speeding up the melting of mountain glaciers, ice sheets, and the Arctic ice cap.

The tiny particles have also been linked to premature death from heart disease and lung cancer.

Ground-level, or tropospheric, ozone — a major ingredient of urban smog — is both a powerful greenhouse gas and a noxious air pollutant. It is formed from other gases including methane, itself a potent driver of global warming.

A threefold increase in concentrations in the northern hemisphere over the last century has made it the third most important greenhouse gas.

Unlike carbon dioxide, which lingers in the atmosphere for centuries once emitted, black carbon and ozone disappear quickly when emissions taper off.

“The science of short-lived climate forcers has evolved to a level of maturity that now requires … a robust policy response by nations,” said Achim Steiner, Executive Director of UNEP.

Measures recommended for reducing black carbon include mandatory use of diesel filters on vehicles, phasing out wood-burning stoves in rich countries, use of clean-burning biomass stoves for cooking and heating in developing nations, and a ban on the open burning of agricultural waste.

For ozone, the report calls for policies that curb organic waste, require water treatment facilities to recover gas, reduce methane emissions from coal and oil industries, and promote anaerobic digestion of manure from cattle and pigs, both major sources of methane.

The report estimates that nearly 2.5 million deaths from outdoor pollution, mainly in Africa and Asia, could be avoided every year by 2030 if black carbon levels dropped significantly.

Far less ground-level ozone could also avoid important losses in global maize, rice, soybean and wheat production, it said.

Source: Curb soot and smog to keep Earth cool, says UN – PHYSORG

Date: 14 June 2011

World ‘must invest $40bn a year in forests’: UN

Monday, June 6th, 2011

Investing $40 billion annually in the forest sector is needed for the world to transition into a low carbon, resource-efficient green economy, according to a UN report released here Sunday.

The additional investment “could halve deforestation rates by 2030, increase rates of tree planting by around 140 per cent by 2050,” said the report published by the Nairobi-based United Nations Environment Programme (UNEP).

“Carefully planned investments would also contribute to increased employment from 25 million today to 30 million by 2050,” it also added.

The cost of ensuring a green transition would equal $40 billion a year or around 0.034 per cent of global GDP, the report said.

Such an investment, equivalent to about two-thirds more than what is currently spent on the sector, would also remove an extra 28 per cent of carbon from the atmosphere, the Nairobi-based UNEP said.

Earlier this week the UNEP warned that fires, felling and agriculture are whittling Europe’s forests down into isolated patches, threatening to speed up desertification and deplete wildlife.

The UN Environment Programme is working with scientists to draw up maps of areas that need to be replanted to help reconnect fragmented forests. The maps will submitted at a June 14-16 ministerial meeting in Oslo.

Source: World ‘must invest $40bn a year in forests’: UN – France 24 International News

Date: 05 June 2011

Global warming crisis may mean world has to suck greenhouse gases from air

Monday, June 6th, 2011

The world may have to resort to technology that sucks greenhouse gases from the air to stave off the worst effects of global warming, the UN climate change chief has said before talks on the issue beginning on Monday.

“We are putting ourselves in a scenario where we will have to develop more powerful technologies to capture emissions out of the atmosphere,” said Christiana Figueres, executive secretary of the UN Framework Convention on Climate Change. “We are getting into very risky territory,” she added, stressing that time was running out.

The UN climate talks starting on Monday in Bonn, which run for the next two weeks, will try to revive the negotiations before the next climate conference, taking place in Durban, South Africa, in December. But little progress is expected, as the negotiating time is likely to be taken up with details such as rules on monitoring emissions.

Figueres tried to inject a greater sense of urgency into the proceedings by pointing to research from the International Energy Agency that found that emissions had soared last year by a record amount. The strong rise means it will take more effort by governments to curb emissions.

Figueres told the Guardian in an interview that governments should act now to save money: “We add $1 trillion to the cost [of tackling climate change] with every year of delay.”

However, as the latest talks begin, the world’s leading climate change official has upset governments by insisting that the aim of the negotiations ought to be to hold warming to less than 1.5C. That would be a much tougher goal than that set by governments last year, which seeks to limit the temperature rise to no more than 2C – the safety threshold, scientists say, beyond which warming becomes catastrophic and irreversible.

“In my book, there is no way we can stick to the goal that we know is completely unacceptable to the most exposed [countries],” Figueres said.

The difference between the two goals may not seem great, but since it has taken more than 20 years of talks for countries to agree on the 2C limit, many are unwilling to reopen the debate. Delegates are conscious that wrangling over whether to stick to 1.5C or 2C was one of the main sources of conflict at the Copenhagen climate summit in 2009; the hope has been that talks can move on to other issues such as how to pay for emissions curbs in poorer countries.

“This is an extraordinary intervention,” said one official involved in the climate talks, who could not be named.

Figueres said that she had the support of the world’s least developed countries, most of Africa, and small island states.

Another factor casting a pall over this year’s talks, which are intended to forge a new global treaty on climate change, is criticism of the South African government, which will host the Durban talks. No interim meetings have yet been set up, and countries have complained of disorganisation and a lack of enthusiasm. But Figueres said: “South Africa has been very carefully listening, trying to understand where there are commonalities and where the weaknesses are.”

She also predicted the US would play a strong role in the talks, despite the Obama administration facing Republican opposition in Congress to action on emissions. “It’s very evident that the legislative body in the US has disengaged, but … the administration continues to be engaged.” she said.

But Todd Stern, chief negotiator for the US, called for participants in the talks to “roll up their sleeves and be constructive.”

Source: Global warming crisis may mean world has to suck greenhouse gases from air – The Guardian UK

Date: 05 June 2011

Worst ever carbon emissions leave climate on the brink

Monday, May 30th, 2011

Greenhouse gas emissions increased by a record amount last year, to the highest carbon output in history, putting hopes of holding global warming to safe levels all but out of reach, according to unpublished estimates from the International Energy Agency.

The shock rise means the goal of preventing a temperature rise of more than 2 degrees Celsius – which scientists say is the threshold for potentially “dangerous climate change” – is likely to be just “a nice Utopia”, according to Fatih Birol, chief economist of the IEA. It also shows the most serious global recession for 80 years has had only a minimal effect on emissions, contrary to some predictions.

Last year, a record 30.6 gigatonnes of carbon dioxide poured into the atmosphere, mainly from burning fossil fuel – a rise of 1.6Gt on 2009, according to estimates from the IEA regarded as the gold standard for emissions data.

“I am very worried. This is the worst news on emissions,” Birol told the Guardian. “It is becoming extremely challenging to remain below 2 degrees. The prospect is getting bleaker. That is what the numbers say.”

Professor Lord Stern of the London School of Economics, the author of the influential Stern Report into the economics of climate change for the Treasury in 2006, warned that if the pattern continued, the results would be dire. “These figures indicate that [emissions] are now close to being back on a ‘business as usual’ path. According to the [Intergovernmental Panel on Climate Change's] projections, such a path … would mean around a 50% chance of a rise in global average temperature of more than 4C by 2100,” he said.

“Such warming would disrupt the lives and livelihoods of hundreds of millions of people across the planet, leading to widespread mass migration and conflict. That is a risk any sane person would seek to drastically reduce.”

Birol said disaster could yet be averted, if governments heed the warning. “If we have bold, decisive and urgent action, very soon, we still have a chance of succeeding,” he said.

The IEA has calculated that if the world is to escape the most damaging effects of global warming, annual energy-related emissions should be no more than 32Gt by 2020. If this year’s emissions rise by as much as they did in 2010, that limit will be exceeded nine years ahead of schedule, making it all but impossible to hold warming to a manageable degree.

Emissions from energy fell slightly between 2008 and 2009, from 29.3Gt to 29Gt, due to the financial crisis. A small rise was predicted for 2010 as economies recovered, but the scale of the increase has shocked the IEA. “I was expecting a rebound, but not such a strong one,” said Birol, who is widely regarded as one of the world’s foremost experts on emissions.

John Sauven, the executive director of Greenpeace UK, said time was running out. “This news should shock the world. Yet even now politicians in each of the great powers are eyeing up extraordinary and risky ways to extract the world’s last remaining reserves of fossil fuels – even from under the melting ice of the Arctic. You don’t put out a fire with gasoline. It will now be up to us to stop them.”

Most of the rise – about three-quarters – has come from developing countries, as rapidly emerging economies have weathered the financial crisis and the recession that has gripped most of the developed world.

But he added that, while the emissions data was bad enough news, there were other factors that made it even less likely that the world would meet its greenhouse gas targets.

  • About 80% of the power stations likely to be in use in 2020 are either already built or under construction, the IEA found. Most of these are fossil fuel power stations unlikely to be taken out of service early, so they will continue to pour out carbon – possibly into the mid-century. The emissions from these stations amount to about 11.2Gt, out of a total of 13.7Gt from the electricity sector. These “locked-in” emissions mean savings must be found elsewhere.

“It means the room for manoeuvre is shrinking,” warned Birol.

  • Another factor that suggests emissions will continue their climb is the crisis in the nuclear power industry. Following the tsunami damage at Fukushima, Japan and Germany have called a halt to their reactor programmes, and other countries are reconsidering nuclear power.

“People may not like nuclear, but it is one of the major technologies for generating electricity without carbon dioxide,” said Birol. The gap left by scaling back the world’s nuclear ambitions is unlikely to be filled entirely by renewable energy, meaning an increased reliance on fossil fuels.

  • Added to that, the United Nations-led negotiations on a new global treaty on climate change have stalled. “The significance of climate change in international policy debates is much less pronounced than it was a few years ago,” said Birol.

He urged governments to take action urgently. “This should be a wake-up call. A chance [of staying below 2 degrees] would be if we had a legally binding international agreement or major moves on clean energy technologies, energy efficiency and other technologies.”

Governments are to meet next week in Bonn for the next round of the UN talks, but little progress is expected.

Sir David King, former chief scientific adviser to the UK government, said the global emissions figures showed that the link between rising GDP and rising emissions had not been broken. “The only people who will be surprised by this are people who have not been reading the situation properly,” he said.

Forthcoming research led by Sir David will show the west has only managed to reduce emissions by relying on imports from countries such as China.

Another telling message from the IEA’s estimates is the relatively small effect that the recession – the worst since the 1930s – had on emissions. Initially, the agency had hoped the resulting reduction in emissions could be maintained, helping to give the world a “breathing space” and set countries on a low-carbon path. The new estimates suggest that opportunity may have been missed.

Source: Worst ever carbon emissions leave climate on the brink – The Guardian UK

Date: 29 May 2011

Benefit to cutting ‘black carbon’

Tuesday, February 22nd, 2011

Cutting atmospheric soot, methane and ground-level ozone is the quickest way to tackle climate change in the short term, according to a new report.

The governing council of the UN Environment Programme (Unep) in Nairobi will hear that reducing these short-lived emissions could reduce warming by half a degree.

And it would be more easily achieved than reducing emissions of the gas principally implicated in long-term climate change, CO2.

It would also have spin-off benefits because soot and ground-level ozone harm human health – and ozone damages crops.

Loss adjustment

The assessment comes from Unep and World Meteorological Organization, in collaboration with a global team of scientists.

Its authors insist that nations must continue to strive to reduce CO2 emissions, which will continue to warm the atmosphere for more than 100 years from the time they are produced.

But it says that using existing technologies and institutions to cut ozone and black carbon (soot) can halve regional warming for 30 to 60 years whilst averting millions of premature deaths and avoiding tens of billions of dollars of crop losses annually.

Black carbon comes from the incomplete combustion of fossil fuels, mostly through diesel engines and biomass burning – including in cook stoves and brick kilns.

It heats the atmosphere directly and also increases warming when particles fall on to snow and ice and reduce their reflectivity.

Ozone in the upper atmosphere protects us from harmful rays. At ground level it is a serious pollutant formed by the action of sunlight on methane, carbon monoxide, volatile organic compounds and oxides of nitrogen.

Methane recovery
The report says: “A small number of emission reduction measures targeting black carbon and ozone precursors could immediately begin to protect climate, public health, water and food security, and ecosystems.

“They include the recovery of methane from coal, oil and gas extraction and transport, methane capture in waste management, use of clean-burning stoves for residential cooking, diesel particulate filters for vehicles and the banning of field burning of agricultural waste.”

It says the task of reducing these gases needs strategic investment and institutional plans and continues: “The identified measures complement but do not replace anticipated carbon dioxide reduction measures.

“Major CO2 reduction strategies mainly target the energy and large industrial sectors and therefore would not necessarily result in significant reductions in emissions of black carbon or the ozone precursors methane and carbon monoxide.

“Significant reduction of the short-lived climate forcers requires a specific strategy, as many are emitted from a large number of small sources.

It has been known for several years that non-CO2 gases are important short-term climate forcers but the impetus to control them was boosted by a paper in Nature Geoscience in April 2009.

A model by Drew Shindell from Nasa’s Goddard Institute for Space Studies suggested that 45% or more of the Arctic warming over the past 30 years was likely to have been caused by changes in black carbon and sulphate aerosol particles.

International strategy

There have been attempts to include short-lived forcing agents into the on-going UN climate talks but although methane is included in the basket of gases to be controlled by rich nations, other ozone precursors and black carbon have been kept out of the talks on the grounds that negotiations are quite complicated enough.

Unep envisages that strategies to tackle the short-lived forcers could be possibly tackled under regional pollution agreements without the need for a global deal.

But some experts still argue that including these pollutants in UN talks would be a benefit.

Dr Mike McCracken, chief scientist for the US NGO The Climate Institute told BBC News: “Most of the emissions on these short-term warming agents are coming from developing countries.

“Most governments want to cut the emissions anyway because of the health of their people and their crops. But because the pollutants aren’t included in the climate talks, the developing countries can’t get any credit for cutting them.

“We have to credit them in the climate talks for creating a global benefit as well as a regional benefit.”

Durwood Zaelke, President of the Institute for Governance & Sustainable Development said: “We also have to start now with aggressive cuts in CO2 if we want to win the longer term climate battle. But it’s not one or the other – we need to cut both CO2 and the other climate forcing agents.

“This assessment makes clear that cutting CO2 now will not reduce warming in the next 20-30 years.  This means passing the 2C level several decades earlier if we don’t reduce these local air pollutants.”

The latest UNEP initiative runs in parallel with another initiative to use the Montreal Protocol on ozone-depleting substances to phase down hydrofluorocarbons, which are also other powerful climate forcers.

Professor David Fowler from the Centre for Ecology and Hydrology in Midlothian told BBC News that the role of ground level ozone was particularly pernicious as ozone pollution was slowing the growth of plants which would otherwise be absorbing CO2 emissions.

“Many countries have introduced controls for the ozone precursors. These have helped knock the peaks off ozone concentrations in the UK, but during the last 20 years the tropospheric background ozone has been growing steadily…and is often in the UK spring close to or in excess of values which effect vegetation.”

In other words, people and crops in the UK are suffering from ground-level ozone pollution provoked by the emission of gases somewhere else in the northern hemisphere.

“The effects of tropospheric ozone on the carbon cycle are similar in magnitude (in radiative terms) to its effects as a greenhouse gas,” Professor Fowler said.

“This background pollution requires hemispheric scale control measures.”

 

Source: Benefit to cutting ‘black carbon’ – BBC News UK

Date: 22 Feb 2011

Carbon emissions threaten fish

Tuesday, July 6th, 2010
Rising acidity levels in oceans due to CO2  is affecting the behaviour of fish in the  larval stage, according to researchers.

Rising acidity levels in oceans due to CO2 is affecting the behaviour of fish in the larval stage, according to researchers.

Baby fish may become easy meat for predators as the world’s oceans become more acidic due to CO2 fallout from human activity, an international team of researchers has discovered.

In a series of experiments reported in the latest issue of the Proceedings of the National Academy of Science (PNAS), the team found that as carbon levels rise and ocean water acidifies, the behaviour of baby fish changes dramatically – in ways that decrease their chances of survival by 500 to 800 per cent.

“As CO2 increases in the atmosphere and dissolves into the oceans, the water becomes slightly more acidic. Eventually this reaches a point where it significantly changes the sense of smell and behaviour of larval fish,”

says team leader Professor Philip Munday of the Australian Research Council’s Centre of Excellence for Coral Reef Studies (CoECRS) at James Cook University.

“Instead of avoiding predators, they become attracted to them. They appear to lose their natural caution and start taking big risks, such as swimming out in the open – with lethal consequences.”

Dr Mark Meekan from the Australian Institute of Marine Science, a co-author on the paper, says the change in fish behaviour could have serious implications for the sustainability of fish populations because fewer baby fish will survive to replenish adult populations.

“Every time we start a car or turn on the light part of the resulting CO2 is absorbed by the oceans, turning them slightly more acidic. Ocean pH has already declined by 0.1 unit and could fall a further 03.-0.4 of a unit if we continue to emit CO2 at our present increasing rate.

“We already know this will have an adverse effect on corals, shellfish, plankton and other organisms with calcified skeletons. Now we are starting to find it could affect other marine life, such as fish.”

Earlier research by Professor Munday and colleagues found that baby ‘Nemo’ clownfish were unable to find their way back to their home reef under more acidic conditions. The latest experiments cover a wider range of fish species and show that acidified sea water produces dangerous changes in fish behaviour.

“If humanity keeps on burning coal and oil at current rates, atmospheric CO2 levels will be 750-1000 parts per million by the end of the century. This will acidify the seas much faster than has happened at any stage in the last 650,000 years.

“In our experiments we created the kind of sea water we will have in the latter part of this century if we do nothing to reduce emissions. We exposed baby fish to it, in an aquarium and then returned some to the sea to see how they behaved.

“When we released them on the reef, we found that they swam further away from shelter and their mortality rates were five to eight times higher than those of normal baby fish,” Professor Munday says.

He adds it should be clearly understood that this impact is likely to happen independent of global warming, and is a direct consequence of human carbon emissions.

The research team concludes

“Our results demonstrate that additional CO2 absorbed into the ocean will reduce recruitment success and have far-reaching consequences for the sustainability of fish populations.”

Professor Munday adds

“In its 2008 report on the state of the world’s fisheries the UN Food and Agriculture Organization said “the maximum wild capture fisheries potential from the world’s oceans has probably been reached”. If you add the impact of ocean acidification and other climate change impacts to this, it means there are grounds for serious concern about the future state of world fish stocks and the amount of food we will be able to obtain from the sea.”

Source: Carbon emissions threaten fish - Sciencealert

Date: 06 July 2010

Arctic Climate May Be More Sensitive to Warming Than Thought, Says New Study

Tuesday, June 29th, 2010
From left to right, Ashley Ballantyne of the University of Colorado at Boulder, Dara Finney of Environment Canada and Natalia Rybczynski of the Canadian Museum of Nature search for fossils in a peat deposit at Strathcona Fiord on Ellesmere Island in Canadas High Arctic. (Photo courtesy Dara Finney, Environment Canada)

From left to right, Ashley Ballantyne of the University of Colorado at Boulder, Dara Finney of Environment Canada and Natalia Rybczynski of the Canadian Museum of Nature search for fossils in a peat deposit at Strathcona Fiord on Ellesmere Island in Canada's High Arctic. (Photo courtesy Dara Finney, Environment Canada)

A new study shows the Arctic climate system may be more sensitive to greenhouse warming than previously thought, and that current levels of Earth’s atmospheric carbon dioxide may be high enough to bring about significant, irreversible shifts in Arctic ecosystems.

Led by the University of Colorado at Boulder, the international study indicated that while the mean annual temperature on Ellesmere Island in the High Arctic during the Pliocene Epoch 2.6 to 5.3 million years ago was about 34 degrees Fahrenheit, or 19 degrees Celsius, warmer than today, CO2 levels were only slightly higher than present. The vast majority of climate scientists agree Earth is warming due to increased concentrations of heat-trapping atmospheric gases generated primarily by human activities like fossil fuel burning and deforestation.

The team used three independent methods of measuring the Pliocene temperatures on Ellesmere Island in Canada’s High Arctic. They included measurements of oxygen isotopes found in the cellulose of fossil trees and mosses that reveal temperatures and precipitation levels tied to ancient water, an analysis of the distribution of lipids in soil bacteria which correlate with temperature, and an inventory of ancient Pliocene plant groups that overlap in range with contemporary vegetation.

“Our findings indicate that CO2 levels of approximately 400 parts per million are sufficient to produce mean annual temperatures in the High Arctic of approximately 0 degrees Celsius (32 degrees F),” Ballantyne said.

“As temperatures approach 0 degrees Celsius, it becomes exceedingly difficult to maintain permanent sea and glacial ice in the Arctic. Thus current levels of CO2 in the atmosphere of approximately 390 parts per million may be approaching a tipping point for irreversible ice-free conditions in the Arctic.”

A paper on the subject is being published in the July issue of the journal Geology. Co-authors included David Greenwood of Brandon University in Manitoba, Canada, Jaap Sinninghe Damste of the Royal Netherlands Institute for Sea Research, Adam Csank of the University of Arizona, Natalia Rybczynski of the Canadian Museum of Nature in Ottawa and Jaelyn Eberle, curator of fossil vertebrates at the University of Colorado Museum of Natural History and an associate professor in the geological sciences department.

Arctic temperatures have risen by about 1.8 degrees F, or 1 degree C, in the past two decades in response to anthropogenic greenhouse warming, a trend expected to continue in the coming decades and centuries, said Ballantyne. Greenhouse gases in the atmosphere have risen from about 280 parts per million during the pre-industrial era on Earth to about 390 parts per million today.

During the Pliocene, Ellesmere Island hosted forests of larch, dwarf birch and northern white cedar trees, as well as mosses and herbs, including cinquefoils. The island also was home to fish, frogs and now extinct mammals that included tiny deer, ancient relatives of the black bear, three-toed horses, small beavers, rabbits, badgers and shrews. Because of the high latitude, the Ellesmere Island site on the Strathcona Fiord was shrouded by darkness six months out of the year, said Rybczynski.

Fossils are often preserved in a process known as permineralization, in which mineral deposits form internal casts of organisms. But at the Ellesmere Island site known as the “Beaver Pond site,” organic materials — including trees, plants and mosses — have been “mummified” in peat deposits, allowing the researchers to conduct detailed, high-quality analyses, said Eberle.

Ballantyne said the high level of preservation of trees and mosses at Ellesmere Island allowed the team to measure the ratio of oxygen isotopes in plant cellulose, providing information on water absorbed from precipitation during the Pliocene and which yielded estimates of past surface temperatures. The team also compared data on the width of tree rings in larch trees at the Beaver Pond site to trees at lower latitudes today to help them estimate past temperatures and precipitation levels.

The researchers also analyzed the distribution of ancient membrane lipids from soil bacteria known as tetraethers, which correlate to temperature. The chemical structure of the fossilized tetraethers makes them highly sensitive to both temperature and acidity, or pH, said Ballantyne.

The last line of evidence put forward by the CU-Boulder-led team was a comparison of Pliocene ancient vegetation at the site with vegetation present today, providing a clear “climate window” showing the overlap of the two time periods.

“The results of the three independent temperature proxies are remarkably consistent,” said Eberle.

“We essentially were able to ‘read’ the vegetation in order to estimate air temperatures in the Pliocene.”

Today, Ellesmere Island is a polar desert that features tundra, permafrost, ice sheets, sparse vegetation and a few small mammals. Temperatures range from roughly minus 37 degrees F, or minus 38 degrees C, in winter to 48 degrees F, or 9 degrees C, in summer. The region is one of the coldest, driest environments on Earth.

“Our findings are somewhat disconcerting regarding the temperatures and greenhouse gas levels during the Pliocene,” said Eberle.

“We already are seeing evidence of both mammals and birds moving northward as the climate warms, and I can’t help but wonder if the Arctic is headed toward conditions similar to those that existed during the Pliocene.”

This is an artists rendering of the Beaver Pond site on Ellesmere Island, in Canadas High Arctic, as it may have looked about 3 to 5 million years ago. (George)

This is an artist's rendering of the Beaver Pond site on Ellesmere Island, in Canada's High Arctic, as it may have looked about 3 to 5 million years ago. (George)

Elevated Arctic temperatures during the Pliocene — which occurred shortly before Earth plunged into an ice age about 2.5 million years ago — are thought to have been driven by the transfer of heat to the polar regions and perhaps by decreased reflectivity of sunlight hitting the Arctic due to a lack of ice, said Ballantyne. One big question is why the Arctic was so sensitive to warming during this period, he said.

Multiple feedback mechanisms have been proposed to explain the amplification of Arctic temperatures, including the reflectivity strength of the sun on Arctic ice and changes in vegetation seasonal cloud cover, said Ballantyne.

“I suspect that it is the interactions between these different feedback mechanisms that ultimately produce the warming temperatures in the Arctic.”

In 2009, CU-Boulder’s National Snow and Ice Data Center showed the September Arctic sea ice extent was 649,000 square miles, or 1,680,902 square kilometers, below the 1979-2000 average, and is declining at a rate of 11.2 percent per decade. Some climate change experts are forecasting that the Arctic summers will become ice-free summers within a decade or two.

In addition to its exceptional preservation of fossil wood, plants, insects and mollusks, the Beaver Pond site on Ellesmere Island is the only reported Pliocene fossil site in the High Arctic to yield vertebrate remains, said Rybczynski.

Eberle said there is high concern by scientists over a proposal to mine coal on Ellesmere Island near the Beaver Pond site by WestStar Resources Inc. headquartered in Vancouver, British Columbia.

“Paleontological sites like the Beaver Pond site are unique and extremely valuable resources that are of international importance,” said Eberle.

“Our concern is that coal mining activities could damage such sites and they will be lost forever.”

Source: Arctic Climate May Be More Sensitive to Warming Than Thought, Says New Study – x-journals

Date: 29 June 2010

Scientist Takes Comprehensive Look at Human Impacts on Ocean Chemistry

Thursday, June 17th, 2010

Numerous studies are documenting the growing effects of climate change, carbon dioxide, pollution and other human-related phenomena on the world’s oceans. But most of those have studied single, isolated sources of pollution and other influences.

Now, a marine geochemist at the Woods Hole Oceanographic Institution (WHOI) has published a report in the latest issue of the journal Science that evaluates the total impact of such factors on the ocean and considers what the future might hold.

“What we do on land — agriculture, fossil fuel combustion and pollution — can have a profound impact on the chemistry of the sea,” says Scott C. Doney, a senior scientist at WHOI and author of the Science report.

“A whole range of these factors have been studied in isolation but have not been put in a single venue.”

Doney’s paper represents a meticulous compilation of the work of others as well as his own research in this area, which includes ocean acidification, climate change, and the global carbon cycle.

He concludes that climate change, rising atmospheric carbon dioxide, excess nutrient inputs, and the many forms of pollution area “altering fundamentally the…ocean, often on a global scale and, in some cases, at rates greatly exceeding those in the historical and recent geological record.”

Source: Scientist Takes Comprehensive Look at Human Impacts on Ocean Chemistry – physorg

Date: 17 June, 2010

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