Although there is great uncertainty about exactly how climate change will affect us, researchers who have prepared reports for the Intergovernmental Panel on Climate Change (IPCC) highlight the following possibilities:

Sea level rises: At present some 46m people live in areas at risk of flooding due to storm surges. Scientists estimate that a 50cm rise in sea level would increase this number to 92 million and a one-metre rise would put 118 million in peril.

If the global ocean level went up by one metre

• Egypt would lose 1% of its land area

• The Netherlands would lose 6%

• Bangladesh would lose 17.5%

• Some 80% of the Majuro Atoll in the Pacific Marshall Islands would disappear under water

Crops and productivity: It is thought that total global crop production would be unchanged but regional effects would vary widely.

• Those most at risk from famine would be people relying on isolated agricultural systems in arid and semi-arid regions

• Populations particularly under threat live in sub-Saharan Africa, south east Asia and tropical areas of Latin America

• Climate change could also alter the range of agricultural pests

Disease: Extensions of the geographical range and season for some organisms could result in increases of diseases like malaria, dengue fever and yellow fever.

• If the temperature increases by 3-5 degrees Centigrade the number of people potentially exposed to malaria could go up from 45% to 60% of the world population and result in an extra 50-80 million cases a year

• Air pollution and exposure to greater extremes in temperature could lead to a greater frequency of asthma and respiratory diseases

Ecosystems: Scientists predict that composition and range of many ecosystems will shift as species respond to climate change

• Research models project that a substantial fraction of the world's forests, and possibly up to two thirds, will undergo major changes. They say the species composiiton will change and some forest may disappear all together

• Deserts are likely to become more extreme, resulting in increased soil erosion

• Mountain glaciers could retreat and inland wetlands would be affected by global warming with resultant changes in habitat for the current species