Scientists' stark warning on reality of warmer world

· Hundreds of millions may be put at risk, says report
· Complaints of political interference with findings

David Adam, Ian Traynor in Brussels
Saturday April 7, 2007
The Guardian

The world's scientists yesterday issued a grim forecast for life on earth when they published their latest assessment of the impacts of climate change.

A warming world will place hundreds of millions of extra people at greater risk of food and water shortages and threaten the survival of thousands of species of plants and animals, they said. Floods, heatwaves, storms and droughts are all expected to increase, with people in poorer countries suffering the worst effects.

Rajendra Pachauri, chair of the panel that published the report, said: "It's the poorest of the poor in the world, and this includes poor people in prosperous societies, who are going to be the worst hit."

The report's release was delayed by arguments between scientists, who wrote the report, and some government representatives present, who must agree the final text and insisted some of its conclusions were weakened.

"The authors lost," one scientist told journalists. "A lot of authors are not going to engage in the IPCC [the UN's Intergovernmental Panel on Climate Change] process any more. I have had it with them." Scientists walked out of the talks at one stage and several lodged protests.

Martin Parry, who co-chaired the working group that produced the report, said it was regrettable that "certain messages were lost", including one table illustrating the impact of climate change according to each degree rise in global temperatures. "But the report was not watered down in the broad thrust," he insisted.

Dr Parry said evidence showed climate change was having a direct effect on animals, plants and water. "For the first time, we are no longer arm-waving with models. This is empirical data."

Four areas were particularly vulnerable: "The Arctic, where temperatures are rising fast and ice is melting; sub-Saharan Africa, where dry areas are forecast to get dryer; small islands, because of their inherent lack of capacity to adapt, and Asian mega-deltas, where billions of people will be at increased risk of flooding."

Neil Adger, a scientist at the Tyndall centre for climate change research at the University of East Anglia, who helped to write the report, said: "There are no winners from the impacts of climate change. No country is immune."

The report, issued in Brussels by the IPCC, says natural systems on all continents and in some oceans are being affected by rising temperatures, and warming caused by human activity is likely to have had "a discernible influence on many physical and biological systems".

Up to 30% of species studied face "an increased risk of extinction" if temperatures climb by 1.5C-2.5C, as they are predicted to this century. A temperature rise beyond 4C would bring "significant extinctions around the globe". Coral reefs, boreal forests and alpine ecosystems could also be damaged irreversibly.

Ian Pearson, environment and climate change minister, said: "This report provides further evidence of why all countries need to work urgently to agree a global deal to combat climate change. But reducing emissions is not enough. We must plan for the changes ahead, including changed stability and security conditions."

Professor Adger said: "Adaptation is necessary, but not a panacea. The report highlights new observations that adaptation is occurring now - local governments and individual farmers, home owners and water and insurance companies are all changing their locations, practices and policies. At present, these efforts are nowhere near sufficient." Yesterday's summary for policy makers report follows a similar UN summary of the science of global warming, which concluded in February that human activity was very likely to be responsible for recent warming.

A third IPCC summary report, on possible ways to tackle the problem, will be published next month.

Prof Adger said the scientists were dismayed to have a passage of the report dropped that made an explicit link between cause and effect on global warming. This had occurred due to political pressure, with China, Russia, and Saudi Arabia being particularly reluctant to endorse some findings.

Hotting up:

Water availability
By 2050 wet areas such as the tropics and high latitude countries will get 10%-40% wetter. Dry and drought affected areas such as sub-Saharan Africa will see less rainfall and get 10%-30% drier.

Ecosystems
Report warns that temperature rise of 1.5C-2.5C means "20%-30% of plant and animal species assessed so far are likely to be at increased risk of extinction". Earlier drafts said they would face "high risk of irreversible extinction".

Food
Some crop yields, such as cereals, could initially increase at mid to high latitudes, but start to decrease in some areas once temperatures climb by more than 3C.

Coasts
Globally there will be increased damage from flooding and erosion, and effects will be worsened by "human-induced" pressures on coastal areas.