Rising temperatures caused by climate change may cost the world economy over $US2 trillion ($A2.63 trillion) in lost productivity by 2030 as hot weather makes it unbearable to work in some parts of the world, according to UN research.

It showed that in Southeast Asia alone, up to 20 per cent of annual work hours may already be lost in jobs with exposure to extreme heat with the figures set to double by 2050 as the effects of climate change deepen. Across the globe, 43 countries will see a…