AFP

South Asia is the world's most climate-vulnerable region, its fast-growing populations badly exposed to flood, drought, storms and sea-level rise, according to a survey of 170 nations published on Wednesday.

Of the 16 countries listed as being at "extreme" risk from climate change over the next 30 years, five are from South Asia, with Bangladesh and India in first and second places, Nepal in fourth, Afghanistan in eighth and Pakistan at 16th.

The Climate Change Vulnerability Index, compiled by a British-based global risks advisory firm, Maplecroft, is intended as a guide for strategic investment and policymaking.

The barometer is based on 42 social, economic and environmental factors, including the responsiveness of government, to assess the risk to population, ecosystems and business from climate change.

South Asia is especially vulnerable because of changes in weather patterns that result in natural disasters, including floods in Pakistan and Bangladesh this year that affected more than 20 million people, Maplecroft said.

"There is growing evidence climate change is increasing the intensity and frequency of climatic events," the firm's environmental analyst, Anna Moss, said.

"Very minor changes to temperature can have major impacts on the human environment, including changes to water availability and crop productivity, the loss of land due to sea-level rise, and the spread of disease."

Bangladesh is rated No.1 because of a double whammy. It has the highest risk of drought and the highest risk of famine.

It is also struggling with extreme poverty, high dependence on agriculture - the economic sector most affected by climate change - and a government that is the least capable of coping with climate impacts.

As for India, "almost the whole (of the country) has a high or extreme degree of sensitivity to climate change, due to acute population pressure and a consequential strain on natural resources," Maplecroft said.

"This is compounded by a high degree of poverty, poor general health and the agricultural dependency of much of the populace."

China (49th), Brazil (81st) and Japan (86th) were among countries in the "high risk" category.

The "medium risk" category included Russia (117th), the United States (129th), Germany (131st), France (133rd) and Britain (138th).

Norway led the group of 11 nations considered at least risk, which is dominated by fellow Scandinavians as well as the Netherlands, which has worked hard to defend its low-lying land from rising seas.

Maplecroft published a climate vulnerability index in 2009 that placed 28 nations at "extreme risk", headed by Somalia, Haiti, Afghanistan, Sierra Leone and Burundi.

However, the 2009 and 2010 indices are not comparable, Maplecroft's Fiona Place said.

The new index, largely reworked, uses three "sub-indices" that focus especially on a country's ability to respond to climate change stress.

"The most serious vulnerabilities to climate change are found in a group of developing countries with socio-economic systems ill-equipped to address development challenges such as food and water security, in addition to being burdened by unstable economies and weak institutions," Place said in an email exchange with AFP.

"This is the case for a large number of countries, with southern Asia and Africa of particular concern."