Key findings

Outlining the report's findings, Martin Parry, co-chairman of IPCC Working Group II, 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, we can actually measure it," he told a news conference.
Key findings of the report include:
75-250 million people across Africa could face water shortages by 2020
Crop yields could increase by 20% in East and Southeast Asia, but decrease by up to 30% in Central and South Asia
Agriculture fed by rainfall could drop by 50% in some African countries by 2020
20-30% of all plant and animal species at increased risk of extinction if temperatures rise between 1.5-2.5C
Glaciers and snow cover expected to decline, reducing water availability in countries supplied by melt water
The report states that the observed increase in the global average temperature was "very likely" due to man-made greenhouse gas emissions.
The scientific work reviewed by IPCC scientists includes more than 29,000 pieces of data on observed changes in physical and biological aspects of the natural world.
Eighty-nine percent of these, it believes, are consistent with a warming world.