
If the world continues with "business as usual", the mean cost of climate change for four countries - Indonesia, the Philippines, Thailand and Vietnam - could be equivalent to losing 6.7 per cent of their combined annual gross domestic product by 2100, more than twice the global average loss.
"Climate change seriously threatens Southeast Asia's families, food supplies and financial prosperity, and regrettably the worst is yet to come," said Ursula Schaefer-Preuss, the ADB's vice president for Knowledge Management and Sustainable Development.
The study said "win-win" mitigation options in the energy sector, particularly in terms of efficiency improvement, could help the region reduce carbon emissions by up to 40 per cent by 2020 at a negative net cost.
Southeast Asia was responsible for 12 per cent of the world's greenhouse-gas emissions in 2000, particularly due to land-use change and the forestry sector.
"The implementation of adaptation and mitigation measures requires the development of comprehensive policy frameworks, incentives for the private sector, elimination of market distortions, and ample financial resources," she said.
The region needs to enhance its capacities to utilise the existing funding resources as well as cooperate with international funds and seek technology transfer, she added.
Aree Wattana Thummakerd, project specialist of the Office of Natural Resources and Environmental Policy and Planning, said Thailand was setting up a policy framework called "National Strategic Place on Climate Change" to encourage all public agencies to take serious action to tackle climate change.
The framework is scheduled for completion in October.
The office will also draft a 10-year master plan, from 2009 to 2019. The plan will comprise six parts: adaptation, mitigation, research and development, capacity-building, planning and international cooperation.
Aree said Thailand recorded greenhouse-gas emission of 3.6 tonnes per head per year, which is close to the global average of 3.8 tonnes.
"Our main objective for the master plan is to cut down greenhouse-gas emission and minimise the effect of climate change, as well as create sustainable development for business, society and the environment in the long run," she added.