Bindu Lohani, ADB's vice president for Knowledge Management and Sustainable Development, speaking at the Second Asia-Pacific Climate Change Adaptation Forum in Bangkok, said resources available to "climate proof" roads, sewers, bridges and pipelines are "grossly inadequate."
"Public lenders and private investors cannot continue to channel billions of dollars to massive infrastructure projects without factoring in the realities of warmer temperatures, rising sea levels and more violent storms," Lohani said in a keynote speech Monday.
Last year ADB approved a record 59 projects supporting environmental sustainability, totaling about $7 billion in financing.
But ADB says that recent estimates indicate that the Asia Pacific region needs to spend about $40 billion per year through 2050 to prepare for the effects of climate change.
Although there are environmental funds, ADB says, there are currently no funds earmarked specifically for addressing climate-induced migration issues.
ADB's new report, "Addressing Climate Change and Migration in Asia and the Pacific," states that more than 42 million people in the region were displaced by environmental disasters over the past two years.
The report urges governments to work with the private sector to introduce sea level index-based insurance, catastrophe bonds and weather derivatives that would attract investors to finance and managing the risks posed by climate change.
"Governments should not wait to act," Lohani said. "By taking steps now, they can reduce vulnerability, strengthen resiliency, and use migration as an adaptation tool rather than let it become an act of desperation."
Also speaking at the forum, Pithaya Pookaman, Thailand's vice minister of Natural Resources and Environment, warned that Bangkok could be submerged within 20 years unless it addresses key issues of infrastructure and land use planning.
Pookaman said Thai Prime Minister Yingluck Shinawatra is heading up a policy board to devise a 10-year master plan to address climate change.
"The successful implementation of these plans and policies depends on… all levels of government and requires better linkage between research and action," Pookaman told the audience.
Pointing to the region's environmental challenges, including the over-exploitation of ecosystems and biodiversity degradation, Pookaman said that "climate change presents a clear and present danger to our lifestyle and existence … our actions to address it are inextricably intertwined with issues of human development."
Some 800 people, including government officials, policy makers, business leaders and economists, from 50 countries attended the two-day forum.