Last year was the second or third warmest on record behind 2016, and the hottest without an extra dose of heat caused by an El Niño event in the Pacific Ocean, the United Nations (UN) .
Average surface temperatures in 2017 were 1.1°C (2.0 Fahrenheit) above pre-industrial times, creeping towards a 1.5°C (2.7 F) ceiling set as the most ambitious limit for global warming by almost 200 nations under the 2015 Paris climate agreement.
No El Niño last year
Last year was indistinguishable, so far, from 2015 as the second or third warmest behind 2016, making 2017 "the warmest year without an El Niño”, the UN’s World Meteorological Organization (WMO) said.
Temperatures in both 2016 and 2015 were lifted by an El Niño , a natural event which can disrupt weather patterns worldwide every few years and releases heat from the Pacific Ocean into the atmosphere.
Seventeen of the warmest 18 years since records began in the 19th century have now happened since 2000, confirming that ever more greenhouse gases are driving up temperatures, the WMO said.
Among extreme weather events last year, the Caribbean and the United States suffered a battering from hurricanes, the Arctic ended 2017 with the least sea ice for mid-winter and tropical coral reefs suffered from high water temperatures.
Warmth in Arctic
Arctic warmth has been especially pronounced and this will have profound and long-lasting repercussions on sea levels, and on weather patterns in other parts of the world
The findings, which match a projection by the WMO in November, now have full-year data including from NASA, the U.S. National Oceanic and Atmospheric Administration (NOAA) and Britain’s Met Office with the University of East Anglia.
In the U.S. alone, weather and climate-related disasters cost the U.S. a record $306 billion in 2017, especially western wildfires and hurricanes Harvey, Maria and Irma, NOAA said last week.