People who are poor are least able to adapt to climate change

The poorest of the poor in the world - and this includes poor people in prosperous societies - are going to be the worst hit.

"Climate change is no longer just an environmental issue, it is a looming humanitarian catastrophe," said Friends of the Earth International's climate campaigner, Catherine Pearce.

"By 2020, between 75 and 250 million people [in Africa] are projected to be exposed to an increase of water stress due to climate change,"

African agricultural production is projected to be "severely compromised by climate variability and change," with decreases likely in the area suitable for agriculture, the length of the growing season and yield potential.

In some countries, yields from rain-fed agriculture could be reduced by up to 20 per cent by 2020,causing wide spread starvation and conflict.

Environmental Refugees ~ Women and children - Redcross Centre in Zinder NIGER

Asian coastal areas, especially the big cities in the seven "mega-deltas" from India's Ganges to China's Yangtze, will be at greatly increased risk of flooding, with an associated increase in death to due to diarrhoeal disease, while by 2050, crop yields in central and south Asia may drop by 30 per cent.

In Latin America, water supplies available for human consumption, agriculture and energy generation are predicted to be "significantly affected" by changes in rainfall patterns and the disappearance of Andean glaciers. Parts of the Amazon rainforest are likely to turn into semi-arid savannah.

The World Health Organisation (WHO) estimated that changes to the earth's climate was already causing about five million extra cases of severe illness a year and more than 150,000 extra deaths.

Climate change threatens the ability of countries, particularly in low lying coastal areas, to meet basic human needs of adequate food, clean water, a healthy environment, and safe shelter

By 2030, however, the number of climate-related diseases was likely to more than double, with a dramatic increase in heat-related deaths caused by heart failure, respiratory disorders, the spread of infectious diseases increases of diarrhoea and malnutrition and malnutrition from crop failures.

The number of people at risk of flooding by coastal storm surges is projected to increase from the current 75 million to 200 million by 2080, when sea levels may have risen by 40 centimetres.

A separate study of how rising temperatures will affect water supplies found that severe shortages were likely to affect up to a sixth of the world's population who currently rely on melting snow and glacial "fossil" ice. A13_s4_1