Tropical diseases spreading into the US, deserts expanding across Africa and glaciers melting in Europe - the world is likely to be a much nastier place in 2100, according to a UN report released yesterday.
Southern Europe will become more prone to drought. Elsewhere in Europe, flood hazards will increase. Half of Alpine glaciers and large permafrost areas could disappear by the end of the 21st century.
Heat waves may change traditional summer tourist destinations and less reliable snow conditions may hurt winter tourism. Agricultural productivity may increase in northern Europe, but decrease in southern Europe.
"Most of the Earth's people will be on the losing side," said Harvard University environmental scientist Dr James McCarthy, who co-chaired the panel that produced the hardest hitting UN study to date on the forecast of global warming.
The 19-page report by the Intergovernmental Panel on Climate Change summarised 1,000 pages of research by around 700 scientists.
Despite its political sensitivity - the report was subject to line-by-line scrutiny by government representatives - the report is more precise than any of its UN predecessors about global warming.
The message was frightening, saying the effects of man-made climate change will lead to:
more "freak" weather conditions like cyclones, floods and droughts;
massive displacement of populations;
potentially enormous loss of life;
greater risk from diseases like malaria as the mosquito widens its reach;
extinction of entire species as their habitat is wiped out.
More severe droughts in the Great Plains of the US and extreme hurricanes in Florida are forecast in "Climate Change 2001: Impacts, Adaptation and Vulnerability". But the report said poor countries would suffer most.
The impact will include:
Mosquito-borne diseases like malaria and dengue fever spreading further into North America;
glaciers melting in northern Europe, with drought plaguing the southern part of the continent;
deserts eating further into farmland across Africa;
tropical cyclones forcing tens of millions of people to flee low-lying parts of Asia.
The Geneva report followed one released by the panel last month in Shanghai which predicted that global temperatures could rise by as much as 5.8 degrees over the next century.
It said the increase was much higher than expected and there was clear evidence that industrial pollution, including emissions from cars, was to blame.
"The greater the rate of change, the more adverse the effect," said World Bank chief scientist and panel chair Dr Robert Watson.
But effective international action remains elusive, in part because of the reluctance of the US to commit itself to firm targets to reduce emissions of greenhouse gases and the push in developing countries like China toward economic progress.
Greenhouse gases - primarily carbon dioxide produced by burning fossil fuels - trap heat in the atmosphere, according to the theory.
"Most warming in the last 50 years is due to human activities," said Dr Watson. "We need to decarbonise our energy sources over the next 50 years."
International environmental campaigners have given the report a cautious welcome.
Ms Frances Maguire of the environmental pressure group, Friends of the Earth, said European governments should "stand firm and force President George W. Bush to agree an effective international deal on cutting emissions."
UN environment talks in the Netherlands collapsed last November, with the US and Europe failing to agree terms for cutting emissions. The talks are due to resume in July.