LONDON • Man-made global warming is set to produce exceptionally high average temperatures this year and the next, boosted by natural weather phenomena such as El Nino, Britain's top climate and weather body has said in a report.
"It looks very likely that globally 2014, 2015 and 2016 will all be among the very warmest years ever recorded," Professor Rowan Sutton of the National Centre for Atmospheric Science, which contributed to the report, told journalists yesterday. "This is not a fluke... We are seeing the effects of energy steadily accumulating in the earth's oceans and atmosphere, caused by greenhouse gas emissions."
The rate at which global temperatures are increasing is also on track to pick up in the coming years, the report said. The 20-page report from Britain's Met Office, titled "Big changes under way in the climate system?", highlights current transitions in major weather patterns that affect rainfall and temperatures at a regional level.
An El Nino weather pattern centred on the tropical Pacific Ocean is "well under way", the report said, and is shaping up to be one of the most intense on record.
Set to grow stronger in the coming months, the current El Nino - a result of shifting winds and ocean circulation - is likely to result in dry conditions in parts of Asia and Australia, the Met Office said. In contrast, the south-western United States has a strong chance of seeing higher-than-average rainfall.
El Ninos also affect tropical storms, making them less likely in the North Atlantic and more intense in the West Pacific.
Overall, an El Nino is also likely to add a little heat to the general impact of global warming.
Meanwhile, warming sea surface temperatures along the North American west coast point to a reversal of another natural pattern called the Pacific Decadal Oscillation. This, too, could temporarily nudge regional temperatures higher, but has yet to be confirmed, the report said.
Finally, the interplay of ocean currents and atmosphere in the Atlantic - another multi-decade oscillation - is moving the other way, and will have a cooling effect.
"The current warm phase is now 20 years long and historical precedent suggests a return to relatively cool conditions could occur within a few years," the report said.
By itself, that would mean cooler and drier summers in northern Europe, and increased rainfall in the north-eastern US.
Global warming is the main driver of change today, the report concluded. "Very warm temperatures so far this year indicate the continued impact of increasing greenhouse gases," said Professor Stephen Belcher, director of the Met Office Hadley Centre.