Scientists who back the Intergovernmental Panel on Climate Change say there is overwhelming evidence that carbon emissions from industrialization and energy-intensive modern lifestyles have driven an increase in the world's average temperature over the past century. Failed global efforts to significantly reduce emissions means that nations are now focusing efforts on adapting to a hotter earth.
Just as colonialism determined much of Asia's past, adapting to profound disruptions from climate change will determine the region's future, said Rajendra Kuma Pachauri, a co-chairman of the climate panel who has spent the past 26 years working on the issue.
"We have no choice but to start mitigating for climate change today," he said.
Asia's growing economic importance and rapidly urbanizing populations will give it a pivotal role in humanity's handling of climate change, said Saleemul Huq, director of the International Centre for Climate Change and Development at the Independent University in Bangladesh.
"It's where the population is, it's where the young population is, it's where the growth dynamism will occur in the next few decades," Huq said after the IPCC met in Yokohama to endorse a summary of a 32-volume report.
The climate report outlines in unprecedented detail the regional-level threat of conflicts, food shortages, rising deaths from diseases spread through contaminated water and mosquito-borne illnesses such as dengue and malaria. In a region where memories of past famines remain fresh, floods and droughts will likely worsen poverty while pushing food prices and other costs higher, the report said.
"There are so many Asian countries that are among the most vulnerable. We've seen so many extreme events hit Asia in recent years," said Kelly Levin, a senior associate at the World Resources Institute.
In Myanmar and Bangladesh, coastal farmlands are tainted by sea water from storm surges and rising sea levels, making soil too saline in key rice producing regions. In their seas, warming temperatures and rising acidity are killing off tropical coral reefs, endangering vital sources of protein.
In Nepal, which accounts for just 0.02 percent of global emissions of greenhouse gases contributing to global warming, fast melting Himalayan glaciers are triggering floods as overburdened dams collapse.
"We are not primarily responsible but we are the victims of climate change," said Sandeep Chamling Rai, a Nepalese who is international adaptation coordinator for the World Wildlife Fund.
Even in wealthy, industrialized Japan, changing climate is expected to double the risks from floods and deaths due to heat and expand the areas affected by disease-carrying mosquitoes.
Assessing the risks for a region with geography that spans alpine plateaus to rainforests is daunting, especially given the lack of research on areas such as central Asia, said Yasuaki Hijioka, a lead author of the Asia section of the report.
Asia has not made as much progress as Europe and the U.S in assessing risks, Hijioka said. Western countries can draw up policies based on detailed research, he said. "In our case, we can only just show some case studies."
Yet Asia is not lagging in adapting to the changes already underway, said Huq of the International Centre for Climate Change and Development. Use of renewable energy already is expanding rapidly as countries seek to reduce carbon emissions and to counter the environmental degradation brought on by full-steam-ahead industrialization.
Progress is mixed, and it does not always depend on the wealth of the societies involved.