Will Asia-Pacific armed forces find their role in national defense and security shifting significantly in the future as the effects of climate change caused by global warming intensify? If so, how quickly will it happen?

Recent TV pictures and media reports of military helicopters and thousands of soldiers evacuating victims of Typhoon Morakot in Taiwan are just the latest sign of disaster relief becoming a more prominent part of military operations.

Of course, not all natural disasters are linked to climate change. But they are getting more costly as global warming causes more extreme weather, including violent storms, floods and droughts.

In January, two U.N. agencies reported a marked rise in 2008 in the number of deaths and economic losses from disasters compared to the 2000-2007 yearly average. They said that last year, 321 disasters killed more than 235,800 people, affected 211 million others and cost $181 billion.

As in previous years, Asia was the main affected continent. Nine of the top 10 countries with the highest number of disaster-related deaths were in Asia. The death toll in 2008 was three times more than the annual average of just over 66,800 for the eight years to 2007. This was chiefly due Cyclone Nargis, which killed over 138,300 people in Myanmar, and the Sichuan earthquake in China, which caused the deaths of at least 87,470 people.

The U.N. refugee agency is making plans, based on what it believes are conservative estimates, that global warming will force between 200 million and 250 million people from their homes by 2050, about half displaced by sudden disasters and half environmental refugees pushed out by gradual changes like rising sea levels.

Almost every military force in the Asia-Pacific region is configured and trained to some degree for disaster relief, not just within national borders but also beyond. China has been a leader in using its engineering battalions and troops to battle floods and earthquakes in the world’s most populous nation.

Armed forces from the Association of Southeast Asian Nations (ASEAN), and partner nations, including the United States, India, Australia, Japan and Singapore, worked together and with local military authorities on an ad hoc basis to alleviate suffering after a devastating tsunami struck Indonesia and other parts of Asia in December 2004.

The ASEAN Regional Forum on security is now trying to build a more effective disaster response capability. Japan’s National Institute for Defense Studies says in its latest East Asian Strategic Review for 2009 that the first challenge is to work out how to build and strengthen mechanisms for cooperation among the nations providing the assistance. The second is to figure out how to build and strengthen cooperative relationships between the country receiving the aid and the states providing it.

Military planners in the U.S., Europe, Australia, Japan and some other Asian nations are weighing the potential impact of climate change and resource security involving future tensions over the supply of energy, food and fresh water.

Australia’s Defense White Paper in May said that the security effects of climate change were likely to be most pronounced where states had limited capacity to respond to environmental strains. It added that the impact of sea-level rise, changed rainfall patterns and drought, “will place greater pressure on water and food security, including local fisheries.”

A 2007 study by a group of retired U.S. admirals and generals published by the Center for Naval Analyses described climate change as “a threat multiplier for instability” in Asia and other volatile regions of the world.

The panel of scientists and officials advising the U.N. has warned that climate change will have a mostly adverse impact, with the consequences intensifying progressively after 2020 if nothing effective is done to curb greenhouse gas emissions and adapt to a warmer world.

Last year, the European Commission outlined a grim catalog of possible threats in a report on climate change and international security. The list included resource conflicts, tensions over energy supply, risks to coastal regions from rising sea levels, loss of territory and border disputes due to receding coastlines, environmentally-induced migration, political radicalization in weak or failing states, and the undermining of cooperative international relations.

Australia’s Defense White Paper said that the first and main line of defenseinstability caused by global warming and resource shortages should be three-pronged: agreement on international climate change mitigation; coordinated economic assistance strategies to countries in need; and concerted international action to assure energy supply and distribution.

If preventive strategies were to fail, it said Australia’s military might face “new potential sources of conflict related to our planet’s changing climate or resource scarcity,” at the same time as more frequent and severe natural disasters and extreme weather increased demands on the armed forces and other government agencies to provide humanitarian assistance and disaster relief.

If these climate change and resource scarcity predictions are correct, Asia-Pacific armed forces will face pressures in the longer term that may be difficult to reconcile.

They will be expected to guard national borders and protect overseas supply lines, while rendering more assistance both at home and abroad.

This will be a major challenge in a climate-stressed and resource- constrained world. It is one that will inevitably bring about changes in military force structure, deployment patterns and doctrine.

Michael Richardson is a visiting senior research fellow at the Institute of South East Asian Studies.