IPCC report confirms global warming

IPPC report

Damning report seeks to end debate over global warming
Lewis Smith, The Times, London, 03-Feb-2007

New fears on climate raise heat on leaders
Anthony Browne, Tom Baldwin and Mark Henderson, The Times, London, 03-Feb-2007

Science Panel Says Global Warming Is ‘Unequivocal’
By Elisabeth Rosenthal and Andrew C. Revkin, New York Times, 03-Feb-2007

- Mankind to blame for temperature rise
- World 'has decade to prevent disasters'

Global warming is caused by mankind, is here to stay and is getting worse, leading climate scientists have concluded.

In a bleak report to world leaders aimed at assessing the impact and extent of climate change, 2,500 scientists from 113 countries said that the evidence of worsening global warming was overwhelming.

So strong is the evidence linking the warming climate to human actions that only the most irresponsible world leaders can ignore or deny global warming and its causes, a senior UN official said at the launch of the report.

Achim Steiner, the executive director of the UN Environmental Programme (UNEP), said that the authoritative report should remove any doubt over whether man-made climate change was taking place. “February 2 will perhaps one day be remembered as the day the question mark was removed,” he said. “Anyone who would continue to risk inaction will one day in the history books be considered irresponsible.”

David Miliband, the Environment Secretary, was equally certain that the “debate over the science of climate change is well and truly over” and called for immediate international action to address the problem.

He said that there was only a short time left — as little as ten years, according to some scientists — to act to stop runaway temperature rises that will bring a host of natural disasters. Presidents, prime ministers and heads of government treasuries must, he urged, ensure that there is “international political commitment to avoid dangerous climate change”.

The Summary for Policy-makers report was one of a series to be issued this year as part of the fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC). It showed that since the third assessment, carried out in 2001, there has been a deterioration.

The IPCC is regarded as the authoritative voice on the science of global warming, chiefly because its procedures lend themselves to thoroughness and conservatism. Its reports are produced by researchers with acknowledged expertise who have to convince thousands of their peers that their opinions are backed by rigorous evidence. It was established by the UN in 1988, and produces reports every five to six years.

Rajendra Pachauri, the panel chairman, introduced the report, which he said revealed that mankind was having a dramatic impact on the world’s climate: “We are in a sense doing things that haven’t happened in 650,000 years.”

If governments continue to allow unfettered use of fossil fuels, temperatures are estimated to rise by at least 2.4C (4.3F) and perhaps as high as 6.4C. A 4C average rise is the most likely, the report concluded. Six years ago the predictions were for a 1.4C to 5.8C rise, with 3C the most likely, and the report pointed to rising carbon dioxide emissions since 2001 as the cause of the increase.

Even in the most optimistic scenario considered, in which the global economy reduces reliance on heavy industry and rejects fossil fuels in favour of renewable energy, current carbon emissions mean that the world is likely to undergo a 1.8C temperature rise.

The prediction makes the European Union’s target of limiting the rise to 2C even more challenging, and suggests that the 2-3C limit proposed in the Stern report last year will be harder to achieve than was thought.

Scientists agreed that they could say with “very high confidence” that human activities since the Industrial Revolution had warmed the world. Most 20th-century temperature rises were, they said, “very likely” to have been caused by mankind, a strengthening of confidence since 2001 when they said that it was likely.

They concluded: “Global atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values.

“The global increases in carbon dioxide concentration are due primarily to fossil-fuel use and land-use change, while those of methane and nitrous oxide are primarily due to agriculture. Continued greenhouse-gas emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21st century that would very likely be larger than those observed during the 20th.”

Susan Soloman, who jointly led the scientists, said of greenhouse gases: “We have a strong confidence that these things are driving climate change to a substantial degree. There can be no question that greenhouse gases are dominated by human activity.” The report identified effects that have already been observed, including reduction of ice cover, ocean temperature rises and increased sea levels, and more extreme weather such as droughts and heat waves. For the first time the IPCC identified hurricane intensity as having worsened.

Global warming will cause the effects to increase in frequency and strength. By the end of the century, the scientists said, Arctic ice is likely to have disappeared and summer heatwaves in Europe will be common. The report addressed the issue of solar radiation, which has been cited by sceptics about manmade climate change as the likely cause of global warming. The scientists dismissed it as anything but a minor possible contributor.

Despite the White House’s reluctance to take action against climate change, the US sent a delegation to the IPCC and approved the report.

Icy danger

An image of two polar bears apparently stranded on melting ice off Alaska was used around the world yesterday to illustrate the dangers of climate change. These bears, however, were photographed in 2004, late in the summer when the ice melts naturally, and are thought to have swum safely to another ice floe. Disappearing sea ice is the bears’ greatest threat, and the IPCC predicts that it could disappear by the end of the century. However, as such strong swimmers, it is almost impossible for polar bears to be stranded on a breakaway ice floe. It is far more likely that this pair were just taking a breather. [see NY Times article, below]

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- Man is very likely to blame for global change
- Temperature forecast to rise by 4C by 2100

Britain is to spearhead a new drive against climate change by bypassing President Bush and urging US states to join directly with Europe’s own carbon trading scheme.

David Miliband, the Environment Secretary, and MPs will travel to America in a fortnight for talks with states and the Democratic-controlled Senate which back limits on US greenhouse gas emissions. The Government hopes that nine northeastern states and California can eventually join the European Union’s carbon trading scheme in the first step towards a global scheme. The schemes are likely to prove far more effective by working together.

The developments came as the Intergovernmental Panel on Climate Change (IPCC) released its bleakest and most confident assessment yet of the science behind global warming. Its report, prepared by more than 2,500 scientists from 113 countries, predicted that average temperatures are likely to rise by 4C by the end of the century, and said human activities were “very likely” responsible.

Carbon trading schemes, pioneered in the EU, enable polluters to buy and sell emission permits, creating financial incentives to reduce production of greenhouse gases. The trip comes after a UN report published yesterday that confirmed that climate change was almost certainly man-made, and was likely to be far worse than previously thought. The Government said that, in the wake of the report, it would step up international efforts to reach a new global agreement on combating climate change, which would include both the US and developing countries such as India and China.

Ministers are also set to launch a campaign in Britain to encourage people to do more to reduce their own carbon emissions, including a new “carbon calculator” so that individuals can work out how much they are personally responsible for.

Mr Miliband told The Times last night: “The science is moving faster than the politics now. In 2007 we need significant progress at the international level. The UK is showing leadership with its Climate Change Bill, the EU is showing leadership and we hope that other legislatures across the world will take similar action.”

California and the nine northeastern states, frustrated by President Bush’s lack of action, have already set up their own carbon trading schemes. Arnold Schwarzenegger, the Governor of California, and George Pataki, Governor of New York, announced they would like to see ways to link up with the EU trading schemes. Despite good-will on both sides, the issue is fraught with difficulties, with the European Commission still having to resolve various legal issues.

Although there are signs that Mr Bush himself is finally beginning to shift ground, recognising climate change as a “serious problem” in his State of the Union speech last month, he still opposes capping carbon emissions. Mr Miliband will address the Washington Legislators Forum, which has been convened to take advantage of the opportunity created by the Democratic takeover of Congress last month.

Stephen Byers, the former Trade Secretary, will lead a discussion on how US states that have already set limits on greenhouse gases could be invited into the EU scheme. He said last night: “Some of the proposals will bypass the White House, others will engage with sympathetic Republicans. We are seeking to put pressure on President Bush.”

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Dan Crosbie/Canadian Ice Service
Polar bears on chunks of glacial ice in the Bering Sea in 2004. Much
higher temperatures are forecast for the Arctic, climate scientists say.

PARIS, Feb. 2 — In a grim and powerful assessment of the future of the planet, the leading international network of climate scientists has concluded for the first time that global warming is “unequivocal” and that human activity is the main driver, “very likely” causing most of the rise in temperatures since 1950.

They said the world was in for centuries of climbing temperatures, rising seas and shifting weather patterns — unavoidable results of the buildup of heat-trapping gases in the atmosphere.

But their report, released here on Friday by the Intergovernmental Panel on Climate Change, said warming and its harmful consequences could be substantially blunted by prompt action.

While the report provided scant new evidence of a climate apocalypse now, and while it expressly avoided recommending courses of action, officials from the United Nations agencies that created the panel in 1988 said it spoke of the urgent need to limit looming and momentous risks.

“In our daily lives we all respond urgently to dangers that are much less likely than climate change to affect the future of our children,” said Achim Steiner, executive director of the United Nations Environment Program, which administers the panel along with the World Meteorological Organization.

“Feb. 2 will be remembered as the date when uncertainty was removed as to whether humans had anything to do with climate change on this planet,” he went on. “The evidence is on the table.”

The report is the panel’s fourth assessment since 1990 on the causes and consequences of climate change, but it is the first in which the group asserts with near certainty — more than 90 percent confidence — that carbon dioxide and other greenhouse gases from human activities have been the main causes of warming in the past half century.

In its last report, in 2001, the panel, consisting of hundreds of scientists and reviewers, said the confidence level for its projections was “likely,” or 66 to 90 percent. That level has now been raised to “very likely,” better than 90 percent. Both reports are online at www.ipcc.ch.

The Bush administration, which until recently avoided directly accepting that humans were warming the planet in potentially harmful ways, embraced the findings, which had been approved by representatives from the United States and 112 other countries on Thursday night.

Administration officials asserted Friday that the United States had played a leading role in studying and combating climate change, in part by an investment of an average of almost $5 billion a year for the past six years in research and tax incentives for new technologies.

At the same time, Secretary of Energy Samuel Bodman rejected the idea of unilateral limits on emissions. “We are a small contributor to the overall, when you look at the rest of the world, so it’s really got to be a global solution,” he said.

The United States, with about 5 percent of the world’s population, contributes about a quarter of greenhouse gas emissions, more than any other country.

Democratic lawmakers quickly fired off a round of news releases using the report to bolster a fresh flock of proposed bills aimed at cutting emissions of greenhouse gases. Senator James M. Inhofe, the Oklahoma Republican who has called the idea of dangerous human-driven warming a hoax, issued a news release headed “Corruption of Science” that rejected the report as “a political document.”

The new report says the global climate is likely to warm 3.5 to 8 degrees Fahrenheit if carbon dioxide concentrations in the atmosphere reach twice the levels of 1750, before the Industrial Revolution.

Many energy and environment experts see such a doubling, or worse, as a foregone conclusion after 2050 unless there is a prompt and sustained shift away from the 20th-century pattern of unfettered burning of coal and oil, the main sources of carbon dioxide, and an aggressive expansion of nonpolluting sources of energy.

And the report says there is a more than a 1-in-10 chance of much greater warming, a risk that many experts say is far too high to ignore.

Even a level of warming that falls in the middle of the group’s range of projections would be likely to cause significant stress to ecosystems, according to many climate experts and biologists. And it would alter longstanding climate patterns that shape water supplies and agricultural production.

Moreover, the warming has set in motion a rise in global sea levels, the report says. It forecasts a rise of 7 to 23 inches by 2100 and concludes that seas will continue to rise for at least 1,000 years to come. By comparison, seas rose about 6 to 9 inches in the 20th century.

John P. Holdren, an energy and climate expert at Harvard, said the report “powerfully underscores the need for a massive effort to slow the pace of global climatic disruption before intolerable consequences become inevitable.”

“Since 2001, there has been a torrent of new scientific evidence on the magnitude, human origins and growing impacts of the climatic changes that are under way,” said Mr. Holdren, who is the president of the American Association for the Advancement of Science. “In overwhelming proportions, this evidence has been in the direction of showing faster change, more danger and greater confidence about the dominant role of fossil-fuel burning and tropical deforestation in causing the changes that are being observed.”

The conclusions came after a three-year review of hundreds of studies of past climate shifts; observations of retreating ice, warming and rising seas, and other changes around the planet; and a greatly expanded suite of supercomputer simulations used to test how the earth will respond to a growing blanket of gases that hold heat in the atmosphere.

The section released Friday was a 20-page summary for policymakers, which was approved early in the morning by teams of officials from more than 100 countries after three days and nights of wrangling over wording with the lead authors, all of whom are scientists.

It described far-flung ramifications for both humans and nature.

“It is very likely that hot extremes, heat waves and heavy precipitation events will continue to become more frequent,” said the summary.

Generally, the scientists said, more precipitation will fall at higher latitudes, which are also likely to see lengthened growing seasons. Semi-arid subtropical regions, already chronically plagued by drought, could have a further 20 percent drop in rainfall under the panel’s midrange outlook for increases in the greenhouse gases.

The summary added a new chemical consequence of the buildup of carbon dioxide to the list of mainly climatic and biological effects foreseen in its previous reports: a drop in the pH of seawater as oceans absorb billions of tons of carbon dioxide, which forms carbonic acid when partly dissolved. The ocean would stay alkaline, but marine biologists have said that a change in the direction of acidity could imperil some kinds of corals and plankton.

The report essentially caps a half-century-long effort to discern whether humans, through the buildup of carbon dioxide and other gases released mainly by burning fuels and forests, could influence the earth’s climate system in potentially momentous ways.

The group operates under the aegis of the United Nations and was chartered in 1988 — a year of record heat, burning forests and the first big headlines about global warming — to provide regular reviews of climate science to governments to inform policy choices.

Government officials are involved in shaping the summary of each report, but the scientist-authors, who are unpaid, have the final say over the thousands of pages in four underlying technical reports that will be completed and published later this year.

Big questions remain about the speed and extent of some impending changes, both because of uncertainty about future population and pollution trends and the complex interrelationships of the greenhouse emissions, clouds, dusty kinds of pollution, the oceans and earth’s veneer of life, which both emits and soaks up carbon dioxide and other such gases.

But a broad array of scientists, including authors of the report and independent experts, said the latest analysis was the most sobering view yet of a century of transition — after thousands of years of relatively stable climate conditions — to a new norm of continual change.

Should greenhouse gases continue to accumulate in the atmosphere at even a moderate pace, average temperatures by the end of the century could match those last seen 125,000 years ago, in the previous warm spell between ice ages, the report said.

At that time, the panel said, sea levels were 12 to 20 feet higher than they are now. Much of that extra water is now trapped in the ice sheets of Greenland and Antarctica, which are eroding in some places.

The panel said there was no solid scientific understanding of how rapidly the vast stores of ice in polar regions will melt, so their estimates on new sea levels were based mainly on how much the warmed oceans will expand, and not on contributions from the melting of ice now on land.

Other scientists have recently reported evidence that the glaciers and ice sheets in the Arctic and Antarctic could flow seaward far more quickly than estimated in the past, and they have proposed that the risks to coastal areas could be much more imminent. But the climate change panel is forbidden by its charter to enter into speculation, and so could not include such possible instabilities in its assessment.

Michel Jarraud, the secretary general of the United Nations World Meteorological Organization, said the lack of clarity should offer no one comfort. “The speed with which melting ice sheets are raising sea levels is uncertain, but the report makes clear that sea levels will rise inexorably over the coming centuries,” he said. “It is a question of when and how much, and not if.”

The warming and other climate changes will be highly variable around the world, with the Arctic in particular seeing much higher temperatures, said Susan Solomon, the co-leader of the team writing the summary and the section of the panel’s report on basic science. She is an atmospheric scientist for the National Oceanic and Atmospheric Administration.

The kinds of vulnerabilities are very much dependent on where you are, Dr. Solomon said in a telephone interview. “If you’re living in parts of the tropics and they’re getting drier and you’re a farmer, there are some very acute issues associated with even small changes in rainfall — changes we’re already seeing are significant,” she said. “If you are an Inuit and you’re seeing your sea ice retreating already, that’s affecting your life style and culture.”

The 20-page summary is a sketch of the findings that are most germane to the public and world leaders.

The full report, thousands of pages of technical background, will be released in four sections through the year — the first on basic science, then sections on impacts and options for limiting emissions and limiting inevitable harms, and finally a synthesis of all of the findings near year’s end.

In a news conference in Paris, Dr. Solomon declined to provide her own views on how society should respond to the momentous changes projected in the study.

“I honestly believe that it would be a much better service for me to keep my personal opinions separate than what I can actually offer the world as a scientist,” she said. “My stepson, who is 29, has an utterly different view of risks than I do. People are going to have to make their own judgments.”

Some authors of the report said that no one could honestly point to any remaining uncertainties as justification for further delay.

“Policy makers paid us to do good science, and now we have very high scientific confidence in this work — this is real, this is real, this is real,” said Richard B. Alley, one of the lead authors and a professor at Pennsylvania State University. “So now act, the ball’s back in your court.”

Elisabeth Rosenthal reported from Paris, and Andrew C. Revkin from New York. Felicity Barringer contributed reporting from Washington.

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