April 6 2007 (Bloomberg) - A United Nations panel warned global warming will cause extinctions to mount, water shortages to spread and droughts and floods to become more frequent as man-made emissions of greenhouse gases cause the Earth to warm.

Discussions by the Intergovernmental Panel on Climate Change, that were scheduled to end yesterday, carried on through the night in a "marathon'' session that ended just before 10:15 a.m. local time, IPCC Chairman Rajendra Pachauri told reporters in Brussels. The report's wording, including statements on the degree of confidence of effects associated with climate change was discussed line-by-line by scientists and political envoys.

The Arctic, sub-Saharan Africa, small island states and the big river deltas of Asia are among the most vulnerable areas, while ecosystems such as coral reefs, sea ice, tundra, boreal forests, mountain and Mediterranean regions are at threat, Martin Parry, co-chair of the group that wrote the report, told journalists in a press conference alongside his co-chair, Osvaldo Canziani and Pachauri.

"It is the poorest of the poor in the world, even the poorest in the most prosperous nations, who are going to be the worst hit and are the most vulnerable,'' Pachauri said. "We have far greater regional detail,'' than the last IPCC report in 2001, such as the melting of glaciers, sea-level rise, impacts on agriculture and food security, he said.

High Confidence

As of 1:30 p.m. local time, the completed summary still wasn't available to reporters.

The IPCC will report with "high confidence'' that poor people around the world are "especially vulnerable'' to climate change and that there will be increases in malnutrition, death and disease because of heat waves, floods, storms, fires and droughts, according to a draft document seen by Bloomberg.

The IPCC assigns degrees of confidence to the statements in its summary for policymakers. In its 2001 document, "high confidence'' indicated a certainty of 67 to 95 percent and "very high confidence'' exceeding 95 percent. The thresholds for 2007 weren't included in the draft.

Slides shown to reporters showed that the predicted negative impacts of climate change increase at greater degrees of warming.

A temperature rise of 1 degree Celsius from the end of the twentieth century will leave up to 30 percent of species at increasing risk of extinction, and from 4 degrees, there will be "significant extinctions around the globe,'' the scientists said with high confidence.

Seas Threatened

Corals, among the most vulnerable species, will experience "widespread'' mortality with a warming of 2 to 3 degrees, the authors said, with high confidence.

Cynthia Rosenzweig, one of the report's authors, said in an interview that one source of contention between scientists and representatives of some governments was a statement in the draft that "based on observational evidence from all continents and most oceans, there is very high confidence that many natural systems are being affected by regional climate changes, particularly temperature increases.''

After officials questioned the degree of confidence, Rosenzweig said she presented a protest letter to Pachauri on behalf of herself and other scientists. A compromise was eventually found that listed the statement without giving the degree of confidence, she said, adding that all parties were "comfortable'' with the wording.

U.S Actions

Scientists said two or three countries opposed the wording of 6 or so sections of the 1,572 page document. The U.S. helped bridge gaps, said Steve Schneider, a Stanford University professor who helped write the document and sat through the debate.

``The U.S. was surprisingly helpful,'' said Schneider, who said he's a "basher'' of President George Bush. "I expected it to be troublesome, but 85 percent of what they did was positive or helpful.''

The draft includes warnings of floods, droughts, extinctions and other dangers to humans and species around the world. In small island nations, "sea-level rise is expected to exacerbate inundation, storm surge, erosion and other coastal hazards thus threatening vital infrastructure, settlements and facilities that support the livelihood of island communities,'' the panel states, with very high confidence.

Ocean Temperatures

Today's document will be the second in a series of four reports on climate change, after a Feb. 2 study on the physical scientific evidence. The body last examined the scientific evidence in 2001.

The IPCC on Feb. 2 said temperatures have risen by 0.76 degrees Celsius (1.37 Fahrenheit) since the 19th century, and will rise by another 1.1 to 6.4 degrees this century. It also said global warming is "very likely'' caused by people.

According to the draft, the panel concluded with high confidence that 75 million to 200 million more people in Africa will be exposed to water shortages, rain-dependent agricultural yields could fall by 50 percent by 2020, and the cost of adapting to the changes brought on by global warming could be as much as 10 percent of economic output.

"Poor countries that bear least responsibility will suffer most - and they have no money to respond - but people should also be aware that even the richer countries risk enormous damage,'' said Hans Verolme, director of the World Wildlife Fund's global climate change program.

In Australia, the panel had very high confidence that the Great Barrier Reef will experience a "significant loss of biodiversity by 2020.''

European Floods

There was also very high confidence that "nearly all European regions are anticipated to be negatively affected by some future impacts of climate change,'' including flash floods, increased erosion and "extensive species loss'' of up to 60 percent in some areas.

In Latin America, there was high confidence that eastern parts of the Amazon will gradually change to savannah from forest, and that Pacific Ocean fish stocks will shift to different areas.

Higher Crop Yields

Not all the effects of climate change were deemed negative. In North America, warming was projected with high confidence to increase agricultural yields by 5 to 20 percent, though delegates also said with very high confidence that disturbances from pests, disease and fire are projected to have increasing impacts on forests, and that in some areas, heat waves will increase in duration, number and intensity, endangering the elderly. On April 10, the panel will detail regional impacts in a series of press conferences around the world.
With scientific evidence indicating that the world's poorest people will experience the worst effects of climate change, rich nations who are responsible for historic emissions of greenhouse gases that are blamed for the warming should fund developing nations with $100 billion a year to help them adapt, Christian Aid, a U.K. charity, said today in an e-mailed statement.

On May 4, the third installment of the IPCC's report will detail ways in which people can mitigate climate change. The fourth volume, due in November, will summarize the other three.

To contact the reporter on this story: Alex Morales in Brussels at amorales2@bloomberg.net.

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