Climate change warnings after world's warmest five years on record
The world has experienced its hottest five-year period on record, with rising sea levels, melting ice and extreme weather, the World Meteorological Organisation said.
In an analysis of the global climate between 2011 and 2015, the organisation said temperatures were 0.57C (1.03F) above the 1960-1991 average, making it the hottest five-year period on record worldwide, and on all continents except Africa.
In 2015, temperatures were a record 1C above pre-industrial levels, and 2016 is set to be hotter yet, while greenhouse gases have also hit their highest levels on record.
Man-made climate change is driving extreme weather, with more than half of 79 studies published between 2011 and 2014 by the Bulletin of the American Meteorological Society finding global warming contributed to individual extreme events.
In the case of heatwaves and high temperatures, climate change increased the probability of some events happening by a factor of 10 or more, the WMO said.
The hot summer in western Europe in 2013 and record annual warmth in Europe in 2014 were among some of the events in which climate change played a part.
The signals were not as clear for extreme rainfall or drought b ut heavy rainfall which led to devastating flooding in the UK in December last year was made about 40% more likely because of climate change, research found.
Record global temperatures have been accompanied by declining Arctic sea ice, melting of the Greenland ice sheet and mountain glaciers, while sea levels have been rising on average by 3mm a year since 1993.
Professor Peter Stott, from the Met Office, which contributed to the report, said looking across a five-year period smoothed out the natural variation seen in any one year to give a "clear picture" of changes to the climate system.
He said the report showed consistency of evidence of human-induced climate change across different areas, from temperatures to Arctic ice, Greenland's glaciers, sea level rises and extreme weather events.
"When we put all this evidence together across the climate system over a period of time, we can be really confident the climate is changing, we can see the fingerprint of human activity and what that really means."
He added: "Climate change is not just something happening in the future - it will happen in the future and it will get worse with future emissions, but it's not just about the future, it's not just about a theoretical possibility.
"It's happening now and it's having an impact."
The five-year assessment comes just days after entry into force of the Paris Agreement, the world's first comprehensive climate deal in which countries committed to drive down emissions to curb temperature rises.
It is being published for the latest round of United Nations climate talks in Marrakech, Morocco, which are expected to focus on implementing the agreement secured in the French capital last December.
WMO secretary-general Petteri Taalas said: "The Paris Agreement aims at limiting the global temperature increase to well below 2C and pursuing efforts towards 1.5C above pre-industrial levels.
"This report confirms that the average temperature in 2015 had already reached the 1C mark. We just had the hottest five-year period on record, with 2015 claiming the title of hottest individual year. Even that record is likely to be beaten in 2016.
"The effects of climate change have been consistently visible on the global scale since the 1980s: rising global temperature, both over land and in the ocean; sea-level rise; and the widespread melting of ice.
"It has increased the risks of extreme events such as heatwaves, drought, record rainfall and damaging floods."