Global warming will cost the world economy more than £1.5 trillion a year in lost productivity by 2030 as it becomes too hot to work in many jobs, according to a major new report.

In just 14 years' time in India, where some jobs are already shared by two people to allow regular breaks from the heat, the bill will be £340bn a year.

China is predicted to experience similar losses, while other countries among the worst affected include Indonesia (£188bn), Malaysia (£188bn) and Thailand (£113bn).

The figures were published in a research paper launched at a forum on how to reduce the risks of severe weather events held in Kuala Lumpur by the United Nations University and UN Development Programme.

Other papers highlighted the risk of increasingly heavy rain helping to spread diseases by expanding insect-breeding sites, driving rodents from their burrows and contaminating freshwater supplies; a decline in air quality caused by fires and dust storms; and more floods, mudslides, drought and high winds.

Dr Tord Kjellstrom, author of the paper on the effect of ‘heat stress’ on the economy, told The Independent: “The effect of heat on people’s daily lives and particular on their work has not been given enough attention.

“If you are physically active in work, the hotter it is, the slower you work. Your body adapts to the heat and in doing that it protects you from the heat.

“For individual countries, even within a short timespan, the losses due to the increasing heat can be in the many billions.”

Dr Kjellstrom, of the Health and Environment International Trust in New Zealand, said the increases in temperature until about 2050 were already inevitable.

Ludovico Einaudi plays the piano as Arctic melts around him

However he said reducing emissions now could still have a significant impact after that date.

“Beyond 2050, it will make a big difference if we take action now to reduce greenhouse gas emissions globally,” Dr Kjellstrom said.

However he said some countries appeared to be planning simply to cope with the coming changes, rather than try to prevent them.

“A lot of countries have focussed in the last few years on adaptation with the impression that we can find methods to adjust to the future changes in climate … and protect people and protect our societies,” he said.

“I think personally that the need for mitigation, which means to reduce climate change, has not been given enough focus.

“It’s quite urgent because the action needs to be taken now, not 40 years from now.”

Climate change protests around the world Show all 25 1 /25 Climate change protests around the world Climate change protests around the world People rally to promote climate protection in Rome, Italy Climate change protests around the world Hundreds of demonstrators gather in front of City Hall in Los Angeles, California EPA Climate change protests around the world People hold hands to form a human chain during a gathering called by ecologist organisations in Marseille, southern France, to protest against global warming a day ahead of the United Nations Conference on Climate Change (COP21) held in Paris Climate change protests around the world Demonstrators clash with French riot police during protests on Place de la Republique, ahead of the COP21 World Climate Change Conference 2015 in Paris, France Climate change protests around the world Demonstrators clash with French riot police during a protest on Place de la Republique ahead of the COP21 World Climate Change Conference 2015 in Paris, France Climate change protests around the world A group of people perform during a rally to promote climate protection in Rio de Janeiro, Brazil Climate change protests around the world A protester sits next to his sign that reads 'Monsanto the Devil Incorporated ' as he joined hundreds of demonstrators who gathered in front of City Hall in Los Angeles, California EPA Climate change protests around the world Environmentalists dance during a protest near the Place de la Republique after the cancellation of a planned climate march following shootings in the French capital, ahead of the World Climate Change Conference 2015 (COP21), in Paris, France Reuters Climate change protests around the world People protest next to characters dressed as wild animals during a march against climate change near the Monument to the Revolution, in Mexico City AP Climate change protests around the world Protesters carries a banner while they take part in a protest about climate change at New York City Hall steps in lower Manhattan, New York Reuters Climate change protests around the world People take part in a protest about climate change around New York City Hall at lower Manhattan, New York Reuters Climate change protests around the world People rally to promote climate protection in Piazza Castello, Turin, Italy Climate change protests around the world A woman holds a globe during a protest for the global climate day in Lugano, Switzerland Climate change protests around the world Yemenis hold banners as they participate in the Global March for Climate in the old city of Sanaía, Yemen Climate change protests around the world Protesters dressed as Santa Claus take part in a protest about climate change at New York City Hall steps in lower Manhattan, New York Reuters Climate change protests around the world People gather at the Legislative Palace in Montevideo, during the Global Climate March to demand action on climate change telling world leaders on the eve of a crunch UN summit that there is "no planet B". From Sydney to London, humid Rio to chilly New York, at least 683,000 hit the streets in 2,300 events across 175 countries at the weekend, co-organiser and campaign group Avaaz said, calling it the largest number of people to protest over climate change all at once Getty Images Climate change protests around the world Climate change protests around the world Demonstrators participate in the Global March for Climate in Athens, Greece Climate change protests around the world A man wearing a Bernie Sanders mask leads hundreds of demonstrators who marched near City Hall in Los Angeles, California EPA Climate change protests around the world Patricia Hauser joined hundreds of demonstrators who gathered in front of City Hall in Los Angeles, California Climate change protests around the world A woman holds a poster of a sick Earth as she joined hundreds of demonstrators who gathered in front of City Hall in Los Angeles, California EPA Climate change protests around the world Hundreds of demonstrators march around City Hall in Los Angeles, California EPA Climate change protests around the world A demonstrator holds cut-out of US Democratic Presidential candidate Bernie Sanders as she joined hundreds of demonstrators who gathered in front of City Hall in Los Angeles, California EPA Climate change protests around the world George Patten holds a sign that reads 'No Fracking Ever!' as he joined hundreds of demonstrators who gathered in front of City Hall in Los Angeles, California EPA Climate change protests around the world Gabrielle Sosa wears 'Rising Sea Levels' sign as she joined hundreds of demonstrators who gathered in front of City Hall in Los Angeles, California EPA

The Paris climate summit last year was hailed as a success with countries committing to keep the amount of warming as close to 1.5 degrees Celsius above pre-industrial levels as possible. The world has already seen nearly 1C of warming.

However the effect of the actions promised by individual states could allow a rise of 3.1C by 2100.

Anthony Capon, director of the UN University’s International Institute for Global Health, said he hoped the research presented at the forum would “help improve understanding … of the threat climate change poses to hard-won advances in human health worldwide”.

"It is not clear yet whether considerations of health and sustainability will overrule the press of economic progress in coming decades, and ethical considerations surrounding the right to development are thorny indeed,” he said.

“Decisions made today will have a profound impact on health around the world for many decades to come.”

In an introduction to the papers, published in a special edition of the Asia Pacific Journal of Public Health, Professor Jamal Hashim and Dr José Siri, both of the UN University, wrote that humanity was facing “substantial health risks from the degradation of the natural life support systems which are critical for human survival”.

But they added: “It has become increasingly apparent that actions to mitigate environmental change have powerful co-benefits for health."

Professor Jamal said the Asia-Pacific region was already seeing more extreme weather events, as predicted by models of climate change.

“It doesn’t look like carbon emissions will reduce significantly in the near future too we may be talking about a further increase in global temperature,” he said.

“I think we will be seeing more and more of this [extreme storms]. How severe and how extreme is anybody’s guess, but we have to be prepared.”

However Professor Jamal added that there were some reasons for optimism.

“I think there’s less argument now about whether there actually is climate change,” he said.