Environment ministers from the South Asian regional grouping, Saarc, have gathered in Bangladesh to discuss a plan to tackle climate change.
Environment ministers from the South Asian regional body, Saarc, have agreed on measures to tackle climate change.
Experts say millions of people in the region could be at risk from rising seas, melting glaciers, floods, droughts and cyclone.
At a meeting in Bangladesh, they decided to share data on weather patterns and their experiences of dealing with natural disasters.
Bangladesh is proposing the creation of a joint fund to help communities adapt to the changing climate.
Experts say tens of millions in the region could be at risk from rising seas, melting glaciers and increased likelihood of floods and droughts.
It says South Asian countries should counter the challenges jointly.
The ministers say they want to speak with one voice in climate change talks.
The BBC's Mark Dummett in Dhaka says the South Asian environment ministers have chosen a good time to come to Bangladesh's capital for Thursday's meeting.
Rich 'must help poor'
The monsoon is in full swing and flood waters are beginning to rise - a reminder of how exposed this region is to the climate.
The BBC's Mark Dummett in Dhaka says this is the first time that the governments of South Asia have met specifically to discuss climate change.
In a matter of weeks, as it happens every year, half the country will be covered with water.
Their environment ministers have agreed to a series of resolutions to pool resources and know-how.
Bleak scenario
Bangladesh, which is frequently hit by massive floods and cyclones, will share its experience of handling large-scale natural disasters.
The fate of the 140 million people living in Bangladesh is closely tied to the weather.
The ministers want South Asia to speak with as one in the international negotiations on climate change and also to appeal jointly for global funds.
They are squeezed between the Bay of Bengal and the huge rivers which flow down from the Himalayas.
Bangladesh's interim prime minister, Fakruddhin Ahmed, said that rich polluting nations had a duty to help poor countries adapt to changes, like rising sea levels, which threaten to inundate coastal areas.
As temperatures rise, scientists forecast that sea levels will inundate coastal regions, and storms will become more frequent.
Our correspondent says the ministers chose a good time to come to Bangladesh - Dhaka has been drenched by days of monsoon rains which have brought its roads to a standstill.
As the Himalayan glaciers melt, there could be worse floods and then droughts.
The rains have also triggered landslides in the south-east which have killed at least nine - further proof of how exposed people there are to the weather.
It is not only Bangladesh which faces this bleak scenario.
All coastal areas along with Afghanistan, Pakistan, Nepal, Bhutan and the heavily populated states of north India are likely to be badly affected by the melting glaciers.
India has unveiled an action plan to fight climate threats
On Monday, India unveiled a national action plan to confront the threat posed by climate change.
The plan envisaged a gradual shift to greater reliance on sustainable sources of energy.
A recent Greenpeace report on climate change in South Asia warned that if greenhouse gas emissions grow at their present rate, the region could face a major human crisis.
It estimated that 75 million people in Bangladesh will lose their homes.
The report also predicted that about 45 million people in India will also become "climate migrants".
Around 130 million people now live in India, Pakistan and Bangladesh in what are called low elevation coastal zones, which comprise coastal regions that are less than 10m above average sea level.
