UN Secretary-General António Guterres has called for urgent climate action and increased ambition ahead of his climate summit in September. His comment comes after the United Nations World Meteorological Organisation (WMO) released data showing the past four years from 2015 to 2018 were officially the ‘four warmest on record’.

The analysis, based on the monitoring performed by five leading international organizations, also shows that the global average surface temperature in 2018 was approximately 1° Celsius above the pre-industrial (1850-1900) baseline.

WMO Secretary-General Petteri Taalas said that the long-term temperature trend is far more important than the ranking of individual years, and that trend is an upward one. He said the 20 warmest years on record have been in the past 22 years.

In order to mobilise political will, Mr Guterres is convening a Climate Summit on 23 September this year.