The gases heating the planet in 2018 were higher than humans have ever recorded, according to an authoritative new report from the American Meteorological Society and the US government.
Greenhouse gas levels topped 60 years of modern measurements and 800,000 years of ice core data, the study found. The data used in the 325-page report is collected from more than 470 scientists in 60 countries.
The global annual average for carbon dioxide – which is elevated because of human activities like driving cars and burning fuel – was 407.4 parts per million, 2.4 ppm higher than in 2017.
The report finds 2018 was the fourth-warmest on record since the mid-to-late- 1800s. Temperatures were .3C to .4C higher than the average between 1981 and 2010.
Sea levels were the highest on record, as global heating melted land-based ice and expanded the oceans. Sea surface temperatures were also near a record high.
As the National Oceanic and Atmospheric Administration put it, the report “found that the major indicators of climate change continued to reflect trends consistent with a warming planet”.
Arctic and Antarctic sea ice extent was near a record low, and glaciers continued to melt and lose mass for the 30th year in a row.
Despite recent massive wildfires in the US and the Arctic, 2018 fire activity around the globe was actually the lowest on record. That is because humans have turned the savannas that have burned frequently into agricultural areas.
Mexico reported its third warmest year in its 48-year record, and Alaska reported its second warmest in its 94-year record. There were 14 weather and climate events in the US that each caused over $1bn in damage – the fourth highest since records began in 1980.
The Caribbean saw coral reef bleaching and South America experienced seven extreme snowfall events. Europe was a hotspot, with its second warmest year since at least 1950. And Australia had its third warmest year since 1910, with a rapidly intensifying and expanding drought and significant fires.