Publication Date January 15, 2020

Fever chart: Earth had its hottest decade on record in 2010s

wildfire extreme heat

Signals Summary: Human-caused climate change caused 2010-2019 to be the hottest decade on record

Article Excerpt: The planet is warming faster than at any time in the history of civilization. 

Five major independent assessments of global temperatures in 2019 each concluded that last year was the second hottest in 140 years of data.


The results mark what many scientists say is a worrisome trend. Global warming is gradual, with some years being warmer and others a tad cooler, with an overall upward shift. The decade beginning in 2010 was the hottest ever, and it’s the fourth in a row to set a new high. The five warmest years occurred since 2015. This year is expected to be similar to 2019. 

Because some factors cool the planet, humanity is responsible for more than 100% of the warming that has been observed, said Katharine Hayhoe, a climate scientist at Texas Tech University.

Under normal conditions, without warming, scientists would expect that 2.5% of the Earth would experience “very high” temperatures in a given year. In 2019, 52% of the Earth did. Almost 10% of the planet set local heat records for average annual temperature; no place broke a cold record, according to Berkeley Earth.


“The impacts of these records are still playing out in Australia with extreme heat, drought and an ongoing bushfires and air quality crisis affecting millions and will do so for decades to come,” said Sophie Lewis, senior lecturer in climate science at the University of New South Wales, Canberra. “This is what climate change looks like.”