Earth broke global annual heat records last year, flirting with the agreed-upon warming threshold and showing more signs of a febrile planet, the European Climate Agency said on Tuesday.
In one of the first of several teams of scientific agencies to calculate how exceptionally warm 2023 was, the European climate agency Copernicus said the year was 1.48 degrees Celsius (2.66 degrees Fahrenheit) above pre-industrial times. That is barely below the 1.5 degrees Celsius limit that the world hoped to stay within in the 2015 Paris climate agreement to avoid the worst effects of warming.
And January 2024 is on track to be so warm that a 12-month period will exceed the 1.5 degree threshold for the first time, said Copernicus deputy director Samantha Burgess. Scientists have repeatedly said that Earth would need an average of 1.5 degrees of warming over 20 to three decades to technically exceed the threshold.
The 1.5 degree target “must be (kept) alive because lives are at risk and choices have to be made,” Burgess said. “And these choices don’t affect you and me, but they do affect our children and grandchildren.”
Record heat made life miserable and sometimes deadly in Europe, North America, China and many other places last year. But scientists say a warming climate is also responsible for more extreme weather events, such as the prolonged drought that devastated the Horn of Africa, the heavy rains that swept away dams and killed thousands of people in Libya, and the wildfires in Canada that pushed the air from North polluted America. to Europe.
In a separate press event on Tuesday, international climate scientists who calculate the role of global warming in extreme weather, the group’s leader, Imperial College climate scientist Friederike Otto, said: “we certainly see in our analysis the strong impact of the fact that this is the hottest year.”
The World Weather Attribution team only looks at events that affect at least 1 million people or kill more than 100 people. But Otto said her team was overwhelmed by more than 160 studies in 2023 and was only able to conduct 14 studies, many of them on killer heat waves. “Basically any heat wave that occurs today has been made more likely and hotter by human-induced climate change,” she said.
Antarctic sea ice reached a record low in 2023, breaking eight monthly records for low sea ice, Copernicus reported.
Copernicus calculated that the global average temperature for 2023 was about one-sixth of a degree Celsius (0.3 degrees Fahrenheit) warmer than the old record of 2016. While that may not seem like much in the global record, it is an exceptionally large margin for the new record, said Burgess. The average global temperature in 2023 was 14.98 degrees Celsius (58.96 degrees Fahrenheit), Copernicus calculated.
“It was a record for seven months. We had the warmest June, July, August, September, October, November and December,” Burgess said. “It wasn’t just a season or a month that was exceptional. It was exceptional for more than half a year.”
There are several factors that made 2023 the hottest year on record, but by far the biggest factor was the ever-increasing amount of greenhouse gases in the atmosphere that trap heat, Burgess said. These gases come from the combustion of coal, oil and natural gas.
Other factors, including the natural El Nino – a temporary warming of the central Pacific Ocean that is changing weather worldwide – other natural fluctuations in the Arctic, Southern and Indian Oceans, increased solar activity and the 2022 eruption of an undersea volcano that will release water vapor into the atmosphere in , Burgess said.
Malte Meinshausen, a climate scientist at the University of Melbourne, said about 1.3 degrees Celsius of the warming comes from greenhouse gases, while another 0.1 degrees Celsius comes from El Nino and the rest are smaller causes.
Copernicus data only goes back to 1940 and is based on a combination of observations and prediction models. Other groups including the United States National Oceanic and Atmospheric Administration and NASA, the United Kingdom Meteorological Office and Berkeley Earth are going back to the mid-19th century and will release their calculations for 2023 on Friday, with expectations of record-breaking figures .
The Japan Meteorological Agency, which uses similar techniques to Copernicus going back to 1948, estimated late last month that this was the hottest year at 1.47 degrees Celsius (2.64 degrees Fahrenheit) above pre-industrial levels. The University of Alabama Huntsville’s global data set, which uses satellite measurements instead of ground data and dates back to 1979, also found last week the warmest year on record, but not by much.
Although actual observations are only less than two centuries old, several scientists say tree rings and ice cores show this is the warmest the Earth has been in more than 100,000 years.
“It basically means that our cities, our roads, our monuments, our farms and in practice all human activities have never had to deal with this warm climate,” Copernicus director Carlo Buontempo said at a press conference on Tuesday. “There were simply no cities, no books, no agriculture or domesticated animals on this planet the last time temperatures were this high.”
In the midst of record warm months, there were days that were downright unprecedentedly hot around the world.
For the first time, Copernicus recorded a day when the Earth’s average temperature was at least 2 degrees Celsius (3.6 degrees Fahrenheit) higher than in pre-industrial times. It happened twice, narrowly missing a third day around Christmas, Burgess said.
And for the first time, every day of the year was at least one degree Celsius (1.8 degrees Fahrenheit) warmer than pre-industrial times. For almost half the year (173 days), the world was 1.5 degrees warmer than in the mid-19th century.
Meinshausen, the Australian climate scientist, said it is normal for the public to wonder whether the 1.5 degree target will be lost. He said it is important that people continue to try to control warming.
“We are not eliminating the speed limit because someone exceeded the speed limit,” he said. “We are redoubling our efforts to put on the brakes.”
But Buontempo said it will only get warmer: “If we follow the current trajectory in a few years, the record year 2023 will probably go down in history as a cold year.”
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