Kolkata and Mumbai are among the cities where the economic exposure to the impacts of extreme climate related events will be highest over the next 30 years, the report found.
The annual release of British risk consultancy Maplecroft's 'Climate Change and Environmental Risk Atlas' reveals that 31 per cent of global economic output will be based in countries facing "high" or "extreme risks" from the impacts of climate change by the year 2025.
According to the Climate Change Vulnerability Index (CCVI), which forms a central part of the Atlas, this includes 67 countries whose estimated combined output of USD 44 trillion will come under increasing threat from the physical impacts of more frequent and extreme climate-related events, such as severe storms, flooding or drought.
The economic impacts of climate change will be most keenly felt by Bangladesh (1st and most at risk), Guinea-Bissau (2nd), Sierra Leone (3rd), Haiti (4th), South Sudan (5th), Nigeria (6th), DR Congo (7th), Cambodia (8th), Philippines (9th) and Ethiopia (10th), which make up the 10 most at risk countries out of the 193 rated by the CCVI.
However, other important growth markets at risk include: India (20th), Pakistan (24th) and Vietnam (26th) in the "extreme risk" category, in addition to Indonesia (38th), Thailand (45th), Kenya (56th) and, most significantly, China (61st), all classified at "high risk."
By 2025, China's GDP is estimated to treble from current levels to USD 28 trillion, while India's is forecast to rise to USD 5 trillion - totalling nearly 23 per cent of global
economic output between them, according to the report.
Maplecroft has also calculated the risks to the world's largest cities to pinpoint where the economic exposure will be highest over the next 30 years.
According to the CCVI's sub-national calculations, of the 50 cities studied, five present an 'extreme risk' - Dhaka in Bangladesh; Mumbai and Kolkata in India; Manila in the Philippines and Thailand's Bangkok - while only London and Paris were classified as "low risk."
The report also said that India's economic exposure to the impacts of extreme climate related events was recently highlighted by Cyclone Phailin.
The storm caused an estimated USD 4.15 billion of damage to the agriculture and power sectors alone in the state of Odisha, which is also India's most important mining region, the report said.
"Cyclone Phailin demonstrates the critical need for business to monitor the changing frequency and intensity of climate related events, especially where infrastructure and logistics are weak," said James Allan, Head of Environment at Maplecroft.