The world's major meteorological agencies have declared 2016 to the hottest year on record - making it three new highs in as many years - as increases in greenhouse gases drove global warming.
NASA's Goddard Institute for Space Studies said global sea and land temperatures last year were 0.99 degrees warmer than average for the 1951-1980 benchmark period, eclipsing the previous high set only a year earlier by 0.12 degrees.
The state of our climate in 2016
Australia is already experiencing an increase in extreme conditions from climate change - and it's projected to get worse.
Australia is already experiencing an increase in extreme conditions from climate change - and it's projected to get worse.
The World Meteorological Organisation, which uses data from NASA, the UK Met Office Hadley Centre and the University of East Anglia's Climatic Research Unit, said temperatures in 2016 were about 1.1 degrees higher than the pre-industrial period, or about 0.83 degrees above the 1961-1990 reference period. That beat the 2015 record by 0.07 degrees.
"2016 was an extreme year for the global climate and stands out as the hottest year on record," said WMO Secretary-General Petteri Taalas.
As expected, all but one of the 16 hottest years on record have occurred this century. 1998 is the other year, and came at the end of the biggest El Nino on record.
Almost two decades on from that spike, 2016 was more than one-third of a degree higher, according to NASA data released on Wednesday. (See NASA chart below.)
"The trends, which we've seen since the 1970s, are continuing and have not paused in any way," Gavin Schmidt, director of NASA's Goddard Institute, told a media briefing.
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| A girl drinks water from an irrigation tube in northern India's Jammu region during a May heatwave. Photo: AP |
Dr Schmidt said the recent El Nino probably boosted 2015 by about half a degree, compared with the trend, and just 0.12 degrees last year. The warming trend is contributing "about 90 per cent of the signal", he said.
Petteri Taalas, WMO's Secretary-General, said in a statement that "carbon dioxide and methane concentrations surged to new records. Both contribute to climate change".
Heatwaves
The record hot year was marked by heatwaves in South Asia and the Middle East, with Kuwait reaching 54 degrees in July - a reading that may be Asia's hottest on record.
Extraordinarily warm northern temperatures have slowed or reversed Arctic sea ice formation this winter, while at the southern end of the planet, Antarctic sea ice has also been tracking at record low levels in satellite data collected over more than three decades.
In combination, climate scientists in the past week have estimated the Earth has not had such low extent of sea ice in thousands of years. With less ice, less solar radiation is reflected back to space, ending up in the exposed seas instead - contributing to further build-up of warmth in the regions.
"Greenland glacier melt - one of the contributors to sea level rise - started early and fast," Mr Taalas said.
"The Arctic is warming twice as fast a the global average," he said. "The persistent loss of sea ice is driving weather, climate and ocean circulation patterns in other parts of the world."
(See NASA chart below for the areas of the planet with the biggest departures from the long-run average temperature.)
2017 outook
Dr Schmidt said he expected this year to see "a small negative push" in temperatures after three years of records.
"It's still going to be a top five year," although unlikely to be a fourth year of records, he said.
For its part, the US National Oceanic and Atmospheric Administration (NOAA) estimated 2016 global temperatures beat the previous year by 0.04 degrees. Differences in accounting for Arctic changes account for some of the discrepancy between agencies.
"Since the start of the 21st century, the annual global temperature record has been broken five times - 2005, 2010, 2014, 2015, and 2016," NOAA said.
"Despite the cooling influence of a weak La Nina in the latter part of the year, the year ended with the third warmest December on record for the globe."
El Nino years tend to spur global temperatures as changing wind patterns in the Pacific means the giant ocean absorbs less heat from the atmosphere. La Ninas reverse the process and tend to suppress global temperatures. (See chart below.)
The 2015-16 El Nino was the third-strongest on record. Conditions
have been mostly neutral since the El Nino pattern broke down in the
first half of last year.For Australia, 2016 was the country's fourth hottest year according to mean temperature data going back to 1910.
Among other agencies recording last year as the hottest on record was Japan's Meteorological Agency, which released preliminary data earlier this week.
Links
- Climate change: Data shows 2016 likely to be warmest year yet
- 2016 hottest year ever recorded – and scientists say human activity to blame
- 2016 breaks record for hottest year ever
- US scientists officially declare 2016 the hottest year on record. That makes three in a row.
- NASA Data Shows 2016 Was Warmest Year on Record Globally
- 2016 was the hottest year ever recorded – UN weather agency
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