2016 the hottest year on record across the world, weather experts say
Last year was the hottest year on record globally, beating 2015's exceptionally high temperatures, the World Meteorological Organisation (WMO) said.
The global average temperature in 2016 was 1.1C higher than pre-industrial levels and about 0.07C higher than the previous record set in 2015, the organisation said.
Along with record temperatures, other long term indicators humans are changing the climate reached new heights in 2016, including levels of greenhouse gases and melting ice, the WMO said.
The analysis is based on data from the UK's Met Office Hadley Centre, the University of East Anglia's Climatic Research Unit, the US National Oceanic and Atmospheric Administration, and Nasa's Goddard Institute for Space Studies.
WMO secretary general Petteri Taalas said: "2016 was an extreme year for the global climate and stands out as the hottest year on record. But temperatures only tell part of the story.
"Long-term indicators of human-caused climate change reached new heights in 2016.
"Carbon dioxide and methane concentrations surged to new records. Both contribute to climate change.
"We have also broken sea ice minimum records in the Arctic and Antarctic.
"Greenland glacier melt - one of the contributors to sea level rise - started early and fast.
"Arctic sea ice was the lowest on record both at the start of the melt season in March and at the height of the normal refreezing period in October and November."
A powerful "El Nino", a weather phenomenon in the Pacific Ocean which pushes up global temperatures, fuelled high temperatures in the early months of 2016.
The Met Office Hadley Centre's acting director Peter Stott said: "A particularly strong El Nino event contributed about 0.2C to the annual average for 2016, which was about 1.1C above the long-term average from 1850 to 1900.
"However, the main contributor to warming over the last 150 years is human influence on climate from increasing greenhouse gases in the atmosphere."
The record prompted renewed calls for a rapid shift away from fossil fuels to curb greenhouse gas emissions and rising temperatures.
WWF-UK chief executive Tanya Steele said: "This is yet again a warning sign for governments, businesses and citizens to speed up the shift to a low-carbon economy.
"From our coral reefs being bleached at an alarming rate, to glaciers melting, and the world facing the first mass extinction of wildlife since the dinosaurs, there are more and more danger signs that we are breaching the environmental limits of our planet."
She said the UK was making progress, but there was a need to drastically improve energy efficiency, switch to renewables and change consumption patterns.
The two US datasets and the one from the UK vary slightly, mostly because of different ways that the polar regions, with little data, are assessed.
The Met Office and UEA figures found that 2016 only exceeded 2015 by a small margin, making the past two years the warmest in records dating back to 1850.
All three sets of data reveal that the planet's average surface temperature has risen by 1.1C (2F) since the late 19th century.
Nasa and Noaa's data both show that 2016 marked three years in a row of record warmth for the globe.
Nasa Goddard Institute for Space Studies (Giss) director Gavin Schmidt said: "2016 is remarkably the third record year in a row in this series.
"We don't expect record years every year, but the ongoing long-term warming trend is clear."
The news comes two days before Donald Trump becomes US president.
Mr Trump has previously labelled climate change a hoax by the Chinese to undermine US manufacturing and pledged to pull out of the world's first comprehensive climate treaty, the Paris Agreement.
UK experts have raised concerns over statements by the president-elect that he does not fully accept the scientific evidence of climate change, while nominees for key posts in his administration have rejected the evidence for global-warming risks.
Friends of the Earth chief executive Craig Bennett said: "This is a clear warning that world leaders, including the incoming US president, mustn't ignore.
"Climate change isn't a hoax - and unless we move rapidly to slash emissions we risk a global catastrophe.
"It's time to ditch our reliance on gas, coal and oil and fully embrace the clean energy revolution that is already upon us."