Some of the world's largest and fastest-growing economies, especially those in South Asia, are most at risk from climate change, finds a new global ranking that calculates the vulnerability of 170 countries to the impacts of climate change over the next 30 years.

Bangladesh residents struggle to cope with floodwaters, October 21, 2011. [File photo]

The 2011 Climate Change Vulnerability Index, released by global risks advisory firm Maplecroft, evaluates 42 social, economic and environmental factors to assess national vulnerabilities across three core areas.

The index is mapped in Maplecroft's Climate Change Risk Atlas 2011, which evaluates the risks to business relating to emissions, unsustainable energy use, regulation and climate change vulnerability.

The countries at the greatest risk are characterized by high levels of poverty, dense populations, and exposure to climate-related events, as well as their reliance on flood-prone and drought-prone agricultural land.

Bangladesh tops the list of countries at extreme risk, and India is close behind in second place. Madagascar is third, Nepal fourth, Mozambique is in fifth place and the Philippines comes sixth.

Haiti, Afghanistan, Zimbabwe and Myanmar (Burma), in that order, round out the top 10 countries listed as at extreme risk. Vietnam and Pakistan are also listed in the extreme risk category, although not in the top 10.

"These countries are attracting high levels of foreign investment from many multinational organizations," said Dr. Matthew Bunce, principal environmental analyst at Maplecroft.

"However, over the next 30 years their vulnerability to climate change will rise due to increases in air temperature, precipitation and humidity," he said.

"This means organizations with operations or assets in these countries will become more exposed to associated risks, such as climate-related natural disasters, resource security and conflict," said Dr. Bunce.

Risk factors include exposure to climate-related natural disasters and sea level rise.

Risks such as human sensitivity in terms of population patterns, development, natural resources, agricultural dependency and conflicts are also factored into the assessment.

Future vulnerability was determined according to the adaptive capacity of a country's government and infrastructure to withstand climate change.

"Understanding climate vulnerability will help companies make their investments more resilient to unexpected change," said Dr. Bunce.

Throughout 2010, changes in weather patterns have resulted in a series of devastating natural disasters, especially in South Asia, where heavy floods in Pakistan killed more than 1,700 people and affected more than 20 million, over 10 percent of the population.