The Asian Development Bank is warning that extreme weather linked to climate change will displace millions more people in the Asia Pacific region in the coming years.

In a report released Tuesday, the bank said more than 42 million people in the region were displaced by environmental disasters in the last two years. ABD Director Bart Edes says he expects that figure to rise as extreme weather patterns become more common.

“The fact that we see people displaced now and many of them becoming migrants gives us a taste of what's to come as climate change begins to have a greater impact in the way of more extreme weather events, as well as slow onset environmental change.”

Edes says the problem is complicated because of a massive population shift to the region's already-crowded megacities, most of which are in vulnerable low-lying coastal areas.

The report calls on governments to strengthen infrastructure in big cities, improve disaster prevention programs, and better protect migrants who have fled their homes because of natural disasters.

Much of Asia has recently been devastated by major floods, including in Thailand, China, Cambodia, Vietnam, the Philippines, North Korea and Australia. At the same time, many countries have also suffered major droughts.

The ABD says increasingly severe storms, droughts and rising sea levels linked to climate change are likely to continue to affect harvests and threaten water supplies in the coming decades for hundreds of millions of Asians who live in environmental hot spots.

It says the Asia Pacific region has six of the 10 countries most vulnerable to climate change. Bangladesh is the most vulnerable, followed by India (2nd), Nepal (4th), Philippines (6th), Afghanistan (8th) and Burma (10th).

But the report said climate change-induced migration can benefit affected areas if governments takes steps, such as providing seasonal labor opportunities for migrant workers and removing barriers for migrants wishing to send money to their home countries.