This year on course to be warmest on record
A young Indian man walks across Upper Lake, Asia's largest artificial lake, west of Madhya Pradesh state capital Bhopal on May 27, 2009. Built by Raja Bhoj during his tenure as a king of Malwa (1005-1055), the lake once served around 40 percent of the surrounding area's residents with nearly 30 million gallons per day but now lies completely dried up due to a lack of rains for the past three years. AFP PHOTO/STR©AFP
This year is on track to be the hottest on record, the UN’s weather agency has reported, and leading scientists say humans are likely to be responsible.
After a year of heatwaves from Australia to Argentina, provisional data from the UN’s World Meteorological Organization show that unless November and December are exceptionally chilly, 2014 will be the warmest year on record. This would mean 14 of the 15 warmest years will have been since the turn of the century.
The data came as British government scientists said that humans are likely to be responsible for the exceptional temperatures.
“We would not be breaking these records without human influence on the climate,” said Peter Stott, the UK Met Office’s head of climate attribution, an emerging field of research enabling the rapid detection of a link between weather extremes and climate change.
“We can say this because we have now got the ability to attribute climate change to specific weather extremes,” he said.
To determine such a link, scientists use climate models to see how likely an abnormal event would be without the human greenhouse gas emissions driving global warming.
Mr Stott said it was “remarkable” to see a record year of heat occur in the absence of an El Niño, a warming water pattern in the eastern Pacific that has boosted temperatures in the recent past.
But he added it was still too early to know whether 2014 signalled an end to the so-called pause in the rate of global warming during the past decade.
The UK is on course for one of its warmest years on record, the Met Office said, as well as its fourth wettest since 1910. Human influences had made breaking the current UK temperature record about 10 times more likely, Mr Stott said.
In depth
The WMO said the record-breaking heat and torrential rains around the world during 2014 were consistent with a changing climate.
“There is no standstill in global warming,” said Michel Jarraud, WMO secretary-general. “What is particularly unusual and alarming this year are the high temperatures of vast areas of the ocean surface, including in the northern hemisphere.”
The news came as thousands of delegates to this year’s UN climate negotiations in Lima arrived for the last big round of talks before a global climate-change deal is due to be sealed in Paris at the end of next year.
It is still far from clear if the Paris agreement will slow greenhouse gas emissions enough to prevent global temperatures rising more than 2C from pre-industrial times, a threshold scientists say it could be dangerous to breach.
The WMO said the average global land and sea surface temperature between January and October was about 0.57C higher than the average recorded between 1961 and 1990.
Global ocean heat content
It was also 0.09C above the average for the past 10 years.
Heatwaves were recorded around the world this year in South Africa, Australia, Brazil and Argentina. At the same time, Australia, the US and Russia endured unusual cold periods, while devastating floods or unusually heavy rains afflicted parts of Europe, Japan and India.
In September, southern parts of the Balkan Peninsula received more than 250 per cent of their monthly average rainfall, a pattern seen in many other regions around the world. Twelve significant Atlantic storms hit the UK last winter.
Global sea surface temperatures were also the highest on record, the WMO said, at about 0.45C above the 1961-1990 average.
Scientists say about 93 per cent of the excess energy trapped in the atmosphere by greenhouse gases produced by burning fossil fuels and other human actions ends up in the oceans.