Chukwumerije Okereke, a professor of global climate governance at Britain’s University of Bristol, said the 1.5 degrees Celsius milestone should serve as “a rude awakening to key political actors to get their act together”.
“Despite all the warnings that scientists have given, nations … are continuing to fail to live up to their responsibilities,” he told Reuters.
Concentrations in the atmosphere of carbon dioxide, the main greenhouse gas, reached a fresh high of 422 parts per million in 2024, C3S said.
Zeke Hausfather, a research scientist at US non-profit Berkeley Earth, said he expected 2025 to be among the hottest years on record, but likely not top the rankings.
“It’s still going to be in the top three warmest years,” he said.
That’s because while the biggest factor warming the climate is human-caused emissions, temperatures in early 2024 got an extra boost from El Nino, a warming weather pattern which is now trending towards its cooler La Nina counterpart.
