THE world's poorest people are suffering more from climate change than had been previously thought, the latest findings published in a report for the World Bank suggest.

Crops are being affected, and sea levels are rising more rapidly in the worst-affected parts of sub-Saharan Africa and South and South-East Asia, even with the current rise in temperatures of 0.8°C. A rise of 50 cm in sea levels is predicted by 2050.

The World Bank's latest report on climate change, Turn Down the Heat: Why a 4°C world must be avoided, argues that if the world warms by only 2°C - as is likely to happen in the next 20-30 years - the effects on poorer countries will be devastating.

Its previous report, by scientists from Climate Analytics and the Potsdam Institute for Climate Impact Research concluded last year that the world will warm by 4°C if action was not taken immediately.

But the same scientists have now found that even a two-degree rise "will cause widespread food shortages, unprecedented heat-waves, and more intense cyclones. . . In the near term, climate change, which is already unfolding, could batter the slums even more, and greatly harm the lives and the hopes of individuals and families who have had little hand in raising the earth's temperature.

"Today, our world is 0.8°C above pre-industrial levels of the 18th century. We could see a 2°C-world in the space of one generation," the report said.

The President of the World Bank, Dr Jim Yong Kim, said: "The result is a dramatic picture of a world of climate- and weather-extremes causing devastation and human suffering. In many cases, multiple threats of increasing extreme heatwaves, sea-level rise, more severe storms, droughts, and floods will have severe negative implications for the poorest and most vulnerable."

As climate change forced people into urban areas, there could be an apocalyptic scenario of "higher numbers of people in informal settlements being exposed to heatwaves, flooding, and diseases", he warned.

Christian Aid has called on governments to act quickly over the report's warning. A senior climate-change adviser for the charity, Dr Alison Doig, said: "This report shows that the current global target of staying below 2°C - previously thought to be a relatively safe level - will, in reality, have a massive impact on people in developing countries.

"Impacts such as extreme heat events, water scarcity and drought, rising sea-levels, and increased hurricane intensity are already being seen more frequently by people in developing countries.

"The report shows how a two-degree global temperature rise will massively increase these threats, while a four-degree rise, which is the current trajectory if significantly more action is not taken to curb emissions, would be devastating and unstoppable. This report gives a stark warning to global leaders to raise their ambition and act to stop climate change as an urgent priority. Efforts so far have been pitiful. The time to act is now.''

But she also attacked the World Bank over its investment in coal-fired power stations. "The World Bank should learn lessons, and lead the world's financial institutes by divesting in fossil fuels, and leading the move to a low-carbon transformation of global energy. At present, it invests billions of dollars every year in coal, oil, and gas," she said.