Hundreds of islands in Indonesia and the Philippines, large swaths of Vietnam?s Mekong Delta and great portions of Thailand and Singapore?s sovereign territory are all under imminent threat. Why, then, the deafening silence? Why no call for urgent action? Perhaps it is because the foe is not a sovereign state, but climate change.

With the world confronting the worst financial crisis since the Great Depression, it is understandable that countries are fixated on short-term measures to stabilize their economies. A new report by the Asian Development Bank??The Economics of Climate Change in Southeast Asia: A Regional Review??explains that countries do not face an either-or choice between addressing the financial crisis and climate change. Failure to address either threat will have catastrophic consequences.

Over the coming decades, climate change will lead to decreasing rainfall in many parts of Southeast Asia, and millions will suffer from water shortages. Rice production from the region, the world?s rice bowl, will appreciably decline, threatening food security. Vast tracts of high-quality forests will give way to tropical savannah and scrub land. Floods, cyclones, droughts and other extreme weather events will become more common. Health threats will also rise, with deaths from cardiovascular and respiratory disease, malaria, and dengue increasing?all because of climate change. As is the case with most disasters, it is the poorest who will suffer the most.

By the end of the century, temperatures in Southeast Asia will dramatically rise. Sea levels could rise 70 centimeters or more, inundating entire islands and low-lying coastal areas. If the world continues with ?business as usual,? Southeast Asian nations could experience combined damages equivalent to more than 6 percent of their countries? gross domestic product on an annual basis, dwarfing the costs of the current financial crisis.

Southeast Asian nations should address the dual threats of the financial crisis and climate change by introducing effective green stimulus programs?as part of larger financial stimulus packages?that can simultaneously shore up their economies, create jobs, reduce poverty, lower carbon emissions and make them more prepared for the worst effects of climate change.

Even under the most optimistic projections, the earth will continue to warm. The overriding priority for Southeast Asian nations must therefore be adapting to climate change. This means improving water management, preparing the agriculture sector for climate change impacts, safeguarding forests and coastal resources and preventing infectious disease outbreaks.

As good global citizens, Southeast Asian nations will also have an increasing responsibility to curb the emission of greenhouse gasses (GHG) that cause global warming. Although Southeast Asia only produced 12 percent of the world?s greenhouse gasses at the turn of the century, the region?s rapidly expanding population and economy means its global share of carbon emissions will increase in the future if no action is taken.

The report notes that the forestry sector is the largest contributor to Southeast Asia?s GHG emissions, and land use change therefore holds the key to successful emissions reduction in the region. This can be achieved by reducing deforestation and land degradation, encouraging the planting of new forests and reforestation and improving forest management.

The energy sector also offers vast, untapped opportunities for emissions reduction. Energy efficiency improvement will allow Southeast Asian nations to mitigate their CO2 emissions by as much as 40 percent by 2020. This ?win-win? measure can actually be implemented at a negative net cost, with energy cost savings outweighing the expense of mitigation. Other important emissions-reducing measures include cleaner transport solutions, sustainable farm management and the increased use of renewable energy sources like wind, biomass and solar.

Implementing these measures would require the development of comprehensive policy frameworks, incentives for private-sector action, elimination of market distortions?and ample financial resources. International funding and technology transfers will be essential for success, as will regional cooperation, particularly in dealing with cross-boundary issues associated with global warming, such as water resources management, natural disasters and disease outbreaks.

While this blueprint is not without its costs, the cost of inaction is even greater, and the long-term benefits of these measures are beyond dispute. Many of these measures can be implemented immediately, as components of broader fiscal stimulus packages, creating much-needed jobs for the region?s people.

Now is the time for Southeast Asian nations to turn adversity on its head, and use the current financial crisis as an opportunity to transform their nations into climate-resilient, low-carbon economies with prosperous futures.

(Dr. Ursula Schaefer-Preuss is vice president of Knowledge Management and Sustainable Development at the Asian Development Bank. Dr. Emil Salim is an economist and a former Indonesian Minister of State for Population and the Environment.)