This will likely be the hottest year on record again: European climate agency

For the second consecutive year, Earth is on track to experience its hottest year on record. This year, for the first time, global temperatures surpassed 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels, the European climate agency Copernicus announced today (7 November).

"It's this relentless nature of the warming that I think is is worrying," said Carlo Buontempo, director of Copernicus.

Buontempo said the data clearly shows the planet would not see such a long sequence of record-breaking temperatures without the constant increase of greenhouse gases in the atmosphere driving global warming. 

He cited other factors that contribute to exceptionally warm years like last year and this one. They include El Nino — the temporary warming of parts of the Pacific that changes weather worldwide — as well as volcanic eruptions that spew water vapor into the air and variations in energy from the sun. But he and other scientists say the long-term increase in temperatures beyond fluctuations like El Nino is a bad sign. 

"A very strong El Nino event is a sneak peek into what the new normal will be about a decade from now," said Zeke Hausfather, a research scientist with the nonprofit Berkeley Earth. 

News of a likely second year of record heat comes a day after Republican Donald Trump, who has called climate change a "hoax" and promised to boost oil drilling and production, was reelected to the presidency. It also comes days before the next UN climate conference, called COP29, is set to begin in Azerbaijan. Talks are expected to focus on how to generate trillions of dollars to help the world transition to clean energes like wind and solar, and thus avoid continued warming.

Buontempo pointed out that going over the 1.5 degree Celsius (2.7 degrees Fahrenheit) threshold of warming for a single year is different than the goal adopted in the 2015 Paris Agreement. That goal was meant to try to cap warming at 1.5 degrees Celsius (2.7 degrees Fahrenheit) since pre-industrial times on average, over 20 or 30 years.

A United Nations report this year said that since the mid-1800s on average, the world has already heated up 1.3 degrees Celsius (2.3 degrees Fahrenheit) — up from previous estimates of 1.1 degrees (2 degrees Fahrenheit) or 1.2 degrees (2.2 degrees Fahrenheit). That's of concern because the U.N. says the greenhouse gas emission reduction goals of the world's nations still aren't nearly ambitious enough to keep the 1.5 degree Celsius target on track.

The target was chosen to try to stave off the worst effects of climate change on humanity, including extreme weather. 

"The heat waves, storm damage, and droughts that we are experiencing now are just the tip of the iceberg," said Natalie Mahowald, chair of Earth and Atmospheric Sciences at Cornell University.