World temperatures hit a record high for the third year in a row in 2016, creeping closer to a ceiling set for global warming with extremes including unprecedented heat in India and ice melt in the Arctic, U.S. government agencies said on Wednesday.
The data, supported by findings from other organizations, was issued two days before the inauguration of U.S. President-elect Donald Trump, who questions whether climate change has a human cause.
Average surface temperatures over land and the oceans in 2016 were 0.94 degrees Celsius (1.69 degrees Fahrenheit) above the 20th-century average of 13.9C (57.0F), according to the U.S. National Oceanic and Atmospheric Administration (NOAA).
U.S. space agency NASA reported almost identical data, and the UK Met Office and University of East Anglia, which also track global temperatures for the United Nations, said 2016 was the hottest year on record.
Temperatures, lifted both by man-made greenhouse gases and a natural El Nino event that released heat from the Pacific Ocean last year, beat the previous record in 2015, when 200 nations agreed a plan to limit global warming. That peak had in turn eclipsed 2014.
"We don't expect record years every year, but the ongoing long-term warming trend is clear," said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies.
Global temperature records date back to the 1880s. Temperatures are unlikely to set a new peak in 2017 after the El Nino faded, even as greenhouse gases from burning fossil fuels keep building up in the atmosphere, led by China and the United States.
Piers Forster, climate expert at the University of Leeds, said this year was likely to be cooler. "However, unless we have a major volcanic eruption, I expect the record to be broken again within a few years," he said. Ash from big eruptions can dim sunlight.
Among last year's extreme weather events, wildfires in Alberta were the costliest natural disaster in Canada's history while Phalodi in west India recorded a temperature of 51C (123.8°F) on May 19, a national record.
North America also had its warmest year on record, the Great Barrier Reef off Australia suffered severe damage from rising temperatures, and sea ice in both the Arctic Ocean and around Antarctica is at record lows for mid-January.
At a conference in Paris in late 2015, governments agreed a plan to phase out fossil fuels this century and shift to renewable energies such as wind and solar power.
They agreed to limit warming to "well below" 2 degrees Celsius (3.6F) above pre-industrial times, while pursuing efforts for 1.5C (2.7F). By that yardstick, the rise stood at about 1.1C (2.0F) in 2016.
"Long-term indicators of human-caused climate change reached new heights in 2016,” Petteri Taalaas, head of the U.N.'s World Meteorological Organisation said, referring to rising levels of carbon dioxide and methane.
Trump, who has described climate change as a hoax, has threatened to cancel the Paris Agreement and shift to exploiting cheap domestic coal, oil and gas. At a meeting in Marrakesh days after Trump's victory, however, almost 200 nations said it was an "urgent duty" to combat climate change.
"The hottest year on record is such a clear warning siren that even President-elect Trump cannot ignore," said Mark Maslin, Professor of Climatology at University College London.