Last year was the warmest ever recorded, U.S. government scientists reported Wednesday.
The U.S. weather and space agencies both said global temperatures reported in 2015 were the highest in the 136 years of record keeping since 1880, the result of the continued atmospheric buildup of heat-trapping greenhouse gases like carbon dioxide and methane.
The National Oceanic and Atmospheric Administration said 2015's average temperature was 14.79 degrees Celsius, 0.9 degrees above the 20th century average and 0.16 degrees higher than the previous record set in 2014.
The National Aeronautics and Space Administration, which measures temperatures differently, also said 2015 was the warmest, although fractionally lower than the weather agency.
It was the fourth time in 11 years that a temperature record was set.
Government record keepers said temperatures above both the Earth's land and sea masses were the highest ever recorded and substantially above the 20th century averages.
The U.S. scientists said the Earth's snow cover was the 11th smallest since that statistic was first recorded in 1968 and the smallest since 2008. The extent of polar sea ice was the sixth smallest in the 37-year history it has been measured.
Countries across the globe agreed at a December summit outside Paris to curb their greenhouse gas emissions over the coming decades.
Global warming – and how to combat it – remains a contentious political issue in the United States, with the world's biggest economy. Some Republican presidential candidates have vowed to revoke the country's support for the pact if they are elected in November to replace Democratic President Barack Obama when he leaves office a year from now.