13 of the 15 warmest years on record have

Since the start of the new millennium, the world has experienced a succession of the warmest years on record.

Now scientists say it is extremely likely these unprecedented high global temperatures have been caused by human emissions from the burning of fossil fuels such as coal and oil.

It comes just days after Nasa confirmed 2015 was the hottest year on record, with temperatures rising 1.8°F (1°C) above those seen before industrialisation.

Global temperatures have set a series of record breaking warm years since the turn of the millennium and a new study has calculated these are 'extremely likely' to have been caused by human greenhouse gas emissions. A skier in Tyrol, Austria struggles to find snow in the warm weather in December (pictured)

The latest study claims it is 'extremely unlikely' that 13 of the 15 hottest years to have occurred since records began 150 years ago would happen since 2000 due to natural variability.

This, they said, suggests it is 600 to 130,000 times more likely than not that human activities and their influence on the climate have caused this record breaking run of hot weather.

2015 WAS HOTTEST ON RECORD Last year was the warmest on record by a considerable margin, according to figures released by a number of different agencies. The National Oceanic and Atmospheric Administration's figures show 2015 was the hottest year in 136 years of record keeping. Its figures showed 2015's temperature was 14.79°C (58.62°F), passing 2014 by a record margin of 0.29 degrees. That's 1.62 degrees above the 20th-century average. Meanwhile, Nasa, which measures differently, found 2015 was 0.23 degrees warmer than the record set in 2014. The dataset produced by the Met Office Hadley Centre and the Climate Research Unit at the University of East Anglia found global mean temperatures reached 1°C above pre-industrial levels for the first time. It said the year's average global temperature was the highest ever recorded. Advertisement

Professor Stefam Rahmstorf, a physicist at the Postdam Institute for Climate Impact Research, in Germany, said: 'Natural climate variations just can't explain the observed recent global heat records, but man-made global warming can.

'It has led to unprecedented local heat waves across the world - sadly resulting in loss of life and aggravating droughts and wildfires.

'The risk of heat extremes has been multiplied due to our interference with the Earth system, as our data analysis shows.'

The researchers, whose work is published in the journal Scientific reports, analysed real world measurements and combined them with computer simulations of the global climate.

This, they continued, allowed them to work out how the climate may have behaved if there had not been any human greenhouse gas emissions.

The results show the odds of human activity being behind the recent spate of record breaking annual global temperatures are far higher than previously believed.

Previous studies conducted in 2015 suggested that the odds of nine of the 10 hottest years occurring since 2000 being due to natural variation in the climate were 650 million to one.

But the new study found the odds have narrowed, with the odds now being one in 5,000.

The researchers compared global temperature measurements with those predicted in computer climate models. The graph above shows the raw climate data in red and the predicted temperatures without greenhouse gas emissions from various computer models in blue and grey

2015 was the hottest year on record, with temperatures rising to 1°C above pre-industrial levels, according to official figures from the Met Office. The global temperature was 0.75°C above the average for 1961 to 1990, making it the warmest since 1850. How 2015 compares to the previous record-holding years is shown

They also found the odds of 13 of the 15 hottest years occurring since 2000 due to natural variation were 1 in 170,000.

Dr Michael Mann, a climate scientist at Pennsylvania State University who was the lead author of the new study, said: 'Natural climate variability causes temperatures to wax and wane over a period of several years, rather than varying erratically from one year to the next.

'That makes it more challenging to accurately assess the chance likelihood of temperature records.

'Given the recent press interest, it just seemed like it was important to do this right, and address, in a defensible way, the interesting and worthwhile question of how unlikely it is that the recent run of record temperatures might have arisen by chance alone.'

Nasa has released data that shows the average global temperature in 2015 (illustrated) was 0.23 degrees warmer than the record set in 2014

It comes after new figures published by the Met Office, Nasa and the National Oceanic and Astmopheric Administration, showed 2015 was the hottest year on record.

Global temperatures were 1.35°F (0.75°C) above the long term average for 1961 and 1990 and was the hottest year to be recorded since records began in 1850.

Professor Rahmstorf added: '2015 is again the warmest year on record, and this can hardly be by chance.'