Even if the United States dug under cold conditions last month, the planet as a whole had its warmest January, scientists said on Thursday.
The warmth came as a surprise to climate researchers. It occurred during the La Niña conditions in the Pacific Ocean, which tend to lower the average temperature of the planet, at least temporarily.
The surface of the Earth has now been so warm for so many of the last two years that scientists are considering whether something else in the chemistry of the planet may have changed, which is boosting temperatures beyond carbon emissions.
These emissions, the by -product of carbon combustion, gas and oil, remain the main driver of global warming, which has reached record levels in both 2023 and 2024.
It is because of La Niña that scientists expect that this year is slightly cooler than the last two years, both lived the opposite model of El Niño. The waters of the eastern tropical Pacific swing between El Niño and La Niña conditions, affecting the weather worldwide, changing the balance between heat in the ocean and heat in the air.
But numerous other factors are also formed at world temperatures. At present, the chances are not high that in 2025 it will end up being the hottest year in the books, Russell Vose, a climate scientist in the National Oceanic and Atmospheric Administration, recently told reporters. But this time last year, researchers say the same thing about 2024, Dr. Vose said. It was wrong.
“So it’s a difficult game, anticipating global temperature,” Dr. Vose said.
According to Copernicus, the European Union climate monitoring organization was much more gloomy last month than usual in northern Canada, Alaska and Siberia, as well as parts of Australia and Antarctica. The abnormally high temperatures above the Hudson Bay and the Labrador Sea helped to shrink the Arctic ice on a low record for January, Copernicus said.
As scientists try to explain the endless series of world warmth, one thing that has been focused is the reduction of air pollution.
In a report this week, James Hansen, the renowned former NASA scientist, claimed that the cutting of pollution had already played an important role in accelerating global warming. The reason is a little opposite: for decades, people not only emit carbon dioxide and other greenhouse gases when fossil fuels are burned. They have also hit tiny sulfate particles in the air.
These particles cause the formation of more and brighter clouds, which help protect the earth from the sun. However, as regulators have limited the pollution of sulfates to protect human lungs, this cooling effect has decreased, exposing the planet to more than the full power of greenhouse heating.
Three decades ago, Dr. Hansen was one of the first scientists to divert wide attention to climate change. Speaking to reporters this week, he argued that the United Nations was badly prepared to deal with accelerated heating.
The UN’s approach to achieving its climate goals still counts on societies to reduce carbon dioxide emissions in the coming decades, he said. These goals now seem “impossible” to achieve, Dr. Hansen said, “If there is no miracle that we do not understand.”
