New York (PTI): South Asia, which is already battling terrorism, could become a more volatile region, if the Himalayan glaciers continue to melt and no step is taken by the world leaders to address the issue, influential American Senator John Kerry has said.

In a major speech on climate change, Mr. Kerry, the Chairman of Senate Foreign Relations Committee, warned that "Himalayan glaciers which supply water to almost a billion people from China to Afghanistan could disappear completely by 2035".

"Think about what that means," Mr. Kerry said appearing before the Council on Foreign Relations in New York.

"Water from the Himalayas flows through India and into Pakistan. India's rivers are not only vital to its agriculture but essential to its religious practice. Pakistan for its part is heavily dependent on irrigated farming in order to avoid famine," he said.

"At a moment when we are scrambling to ratchet down tensions and prepare to invest very significant money to build up capacity in that country, it would be infuriating to think that climate change would actually be working in an opposing direction," Mr. Kerry said.

Noting that at some places in the world climate change can contribute to a more dangerous world, Mr. Kerry said: "Nowhere is the nexus between these threats more acute than perhaps in South Asia, the home of al Qaeda and the center of our terrorist threat."