Researchers have warned that climate change would lock the world into more frequent and severe heatwaves in the next few decades.
They point out that there would be a 'several-fold' increase in heatwaves up to 2040, irrespective of the amount of carbon dioxide released into the atmosphere. They say, however, that future efforts to cut pollution could stem the rise in extreme heat events later on in the century.
The last decade had seen an exceptional number of extreme heatwaves around the world, hitting the US in 2012, Russia in 2010, Australia in 2009, and Europe in 2003, that had adverse impact on health, the economy, agriculture and wildlife.
The soaring monthly and seasonal temperatures associated with heat waves could now largely be attributed to global warming of around 0.5C over the past 50 years, a study published in the Institute of Physics' journal Environmental Letters said.
Extreme summer heat waves, which sent monthly temperatures soaring well above normal, now covered around 5 per cent of the world's land, mostly in the Tropics, but also over western Europe and the Mediterranean, according to the researchers.
However, the percentage of land experiencing summer months of extreme heat was set to double by 2020, and quadruple by 2040 to cover a fifth of the global land surface, the projections using computer climate models found.
Meanwhile, another report warns that global temperatures were rising so rapidly that by 2040 the UK would spend up to a fifth of its summer months in an extreme heatwave.
The report warns that unless something dramatic was done to curb the volume of greenhouse gas emissions widely regarded as responsible for climate change, conditions currently regarded as ''extreme'' would become the ''new normal'' in the UK and most of the world by the end of the century.
The emerging scenario would see Spain and France likely experiencing extreme temperatures during 80 per cent of their summer - across much of June, July and August - with the UK slightly lower at between 50 and 60 per cent, according to Dim Coumou, the lead author of the study from the Potsdam Institute for Climate Impact Research.
This would see the UK's July 2006 heatwave - the hottest month since records began in 1659 with an average temperature of 17.8C - becoming normal.
According to Coumou, the worst hit would be the Mediterranean and the Middle East; the UK would definitely see a very strong increase in heat extremes as well. This would be hugely damaging to agriculture and health, he added.