Food security in Africa is likely to be "severely compromised" by climate change, with production expected to halve by 2020, according to climate change experts.

The projections are contained in a report launched last week in London by the Intergovernmental Panel on Climate Change (IPCC), which was followed by an experts' panel discussion.

"The discussions concluded that Africa is likely to be the most affected [by climate change] partly because of the increasing aridity in the north [the Sahel] and Southern Africa: and these are the most populous parts of the continent," said Martin Parry, the co-chair of the IPCC’s working group which authored the report. He also listed the lack of technology available to adapt to environmental change as increasing the region's vulnerability.

About 25 percent of Africa's population - nearly 200 million people - do not have easy access to water; that figure is expected to jump by another 50 million by 2020 and more than double by the 2050s, according to the report.

Over 95 percent of Africa’s agriculture depends on rainfall, according to the UN's Food and Agriculture Organisation (FAO). "Models indicate that 80,000 square km of agricultural land in sub-Saharan Africa currently deemed constrained will improve as a result of climate change. However, 600,000 square km currently classed as moderately constrained will become severely limited," said the FAO.

Even with a minimal rise in global temperatures, crop production in the southern hemisphere - where rain fed agriculture is the norm - will probably decline, the FAO predicted.

This year drought-affected parts of southern Africa - Zimbabwe, Swaziland and Lesotho - experienced a 40 percent to 60 percent reduction in maize production, for which global warming was partly to blame, noted the World Meteorological Organisation (WMO).

But the IPCC report was more cautious. "The contribution of climate to food insecurity in Africa is still not fully understood, particularly the role of other multiple stresses that enhance impacts of droughts and floods and possible future climate change".

However, the report warned that crop revenues in Africa could fall by as much as 90 percent by 2100 and predicted that wheat production was likely to disappear from Africa by the 2080s.

Mitigate

"It is too late to avoid all climate change impact", warned Parry. "Our choice now is between a damaged world and a severely damaged world...and if we do not restrict carbon emissions now then we may well embark on a pathway to [a global warming] well above two degrees Celsius".

Scientist have speculated that even holding the temperature increase to two degrees Celsius, a target adopted by the European Union, was too high and would be enough to trigger melting of the Greenland ice sheet.

Human activity in Africa was also affecting its ecosystems. Dependency on fuelwood and charcoal as sources of energy in rural areas contributes to about 80 percent to 90 percent of energy needs in low-income households. Besides, fire incidents represent a huge threat to tropical forests in Africa, according to the IPCC report. "An estimated 70 percent of detected forest fires occur in the tropics, with 50 percent of them being in Africa."

Parry called on the industrialised countries participating this week in a historic UN's general assembly debate, 'Responding to Climate Change', to help the developing world by providing them with technology to develop greener energy alternatives such as solar power.

Build resilience

Faced with extreme poverty and lack of resources, African countries should also concentrate on building it's people's resilience, said Parry. "Countries must attempt to reduce the vulnerability of it's people and draw up adaptation plans".

The IPCC report suggests water-harvesting system to supplement rain-fed farming, weather insurance, national grain reserves, cash transfers and school feeding schemes as adaptation measures. It also highlights the benefits of biotechnology research in Africa if it could lead to drought and pest-resistant rice, drought-tolerant maize and insect-resistant millet, sorghum and cassava.

A summary of the IPCC report was published in April this year.

The IPCC set up by the WMO and the United Nations Environment Programme in 1988 is the world's most authoritative voice on climate change. The panel comprising leading world experts assesses scientific, technical and socioeconomic information to understand the risk of climate change and draws up options for adaptation and mitigation.