The record temperatures of this year have forced some scientists to fear that the pace of warming could accelerate. But not everyone agrees.
According to scientists, an increase in the amount of thermal energy that has entered the planet system known as the "energy imbalance" of the planet will accelerate warming. "If you get more energy than it turns out, it gets warmer, and if you double this imbalance, you will warm up faster," Hansen said in an interview.
Zick Horobatko, a climatologist from Earth in Berkeley, also called the temperature "absolutely stunning bananas" for the last few months and noted that "there is more and more evidence that global warming has accelerated over the past 15 years."
But not everyone agrees. Climatologist at the University of Pennsylvania Michael Mann argued that acceleration is not yet visible: "The truth is bad enough," he wrote in his blog. Many other researchers also remain skeptical, saying that although such an increase can be predicted in some climatic simulations, they do not see it clearly in the data from the planet itself. At least so far.
The Washington Post used a NASA data set to analyze global average surface temperatures from 1880 to 2023.
Records show that the pace of warming was clearly accelerated in about 1970. Scientists have long been known that this acceleration is associated with a sharp increase in greenhouse gases in combination with the efforts of many countries to reduce the amount of air pollution that reflects the sun. But the data is much more uncertain about whether the second acceleration occurs.
Between 1880 and 1969, the planet was slowly heated - at a speed of about 0.04 degrees Celsius (0.07 degrees Fahrenheit) over decades. But since the early 1970s, warming has accelerated-reaching 0.19 degrees C (0.34 degrees F) for decades between 1970 and 2023.
Such acceleration does not cause controversy. By the 1970s and 1980s, people burned fossil fuel, but also allocated a huge amount of air or aerosols. Sulfate aerosols are light -colored particles that have the ability to temporarily compensate for part of the warming caused by fossil fuel. They themselves reflect sunlight back into space, and also affect the formation of reflective clouds.
The more aerosols in the air, the slower the planet will heat up: a compromise, which Hansen calls the "Faustic Agreement". The idea is that since aerosol pollutants have a dangerous impact on human health, in the end, society decides to clean them, which leads to sharp warming.
At the beginning and mid-20th century, developed countries were so badly contaminated that the world was slowly heated. "It was an era of London fogs and very extreme pollution in the United States," said Gabharl, a climatologist at the University of Edinburgh. A recent study published in Journal of Advances in Modeling Earth Systems, for example, showed that in the 1980s, these particles compensated for about 80 percent of climate warming.
However, since the 1970s and the 1980s, the impact of aerosol pollution has been leveled, partly thanks to politicians such as amendments to the US law on clean air in 1990. As you can see from the picture above, at the same time, greenhouse gases have increased , which is why aerosols do not have time for them. As a result, a planet appeared, which is now heated much faster than in the first half of the 20th century.
But the data is more vague when it comes to whether the warming rate has accelerated in the last few decades - an increase that can accelerate forest fires, floods, heat waves and other effects around the world. It may take more years of evidence to eliminate the statistical obstacles required by climate science.
"I think we may need three to four years of data," Chris Smith, a climatologist at Lids University, said. "Just a little too early."
Scientists are alert, partly because some of them came to the opposite conclusion about ten years ago. Then some scientists and political commentators suggested that climate change has stopped or slowed down. The arguments in favor of what some people call a break in warming have never been particularly strong - and it does not seem to have changed significantly in the retrospective - but this serves as a warning about the statements that warming is getting faster or slower.
To understand why the situation is currently ambiguous, let us consider the following figure of "Trend trends" based on the analysis of Mark Richardson, a climatologist from the laboratory of NASA jet movement, which last year published statistics, which found that the acceleration of warming could not be clear.
Richardson has considered every 30-year trend in NASA temperature record, starting from 1880 to 1909 to the period from 1994 to 2023. Higher values indicate the higher rates of global warming. Here we will show the result of the period between 1941 and 1970 to better understand how the rate of warming in the second half of the 20th century and whether they are changing now:
Although there is a hint of increasing the rate of warming at the very end of the recording, it has not been as pronounced as the shift since 1970. This helps to explain why many scientists do not yet undertake acceleration.
"The temperature near the ground is only a thin layer, and the temperature is able to fluctuate greatly," Richardson said. For this reason, scientists need more time to make sure that the changes go beyond what you usually expect, he said.
But some scientists believe that temperature data simply do not show the acceleration.
Hansen claims that recent changes in aerosols will cause a strong increase in the speed of warming only in the next few years. In 2020, the International Maritime Organization introduced a rule that requires a significant decrease in sulfur content in fuel oil. The pollution of the sulfur aerosol from the ocean navigation fell sharply.
Most of the present debate about whether warming is faster is rotated by the consequences of these maritime changes, which can potentially affect how much heat is absorbed by vast areas of the oceans. Hansen and his co -authors claim that changing ship emissions contributes to a significant increase in the energy imbalance of the Earth - an additional amount of heat that remains in the Earth's system rather than flowing into space. But not all scientists agree that the rules of contamination of ocean vessels had such a huge impact.
Some climatic models also involve the acceleration of warming in the coming years, as the number of aerosols decreases. "Although there is more and more evidence of the acceleration of warming, it is not necessarily" worse than we thought, "because scientists mostly expect something like that," Hawtko said.
Most agree that it is too early to say whether the second acceleration goes. "An attempt to estimate the basic warming speed in a short period of time is very difficult," said Andrew Desnsler, a climatologist at Texas University of A&M.
"Just because you get a trend that looks like it is very fast, it does not tell you what the basic speed of warming."
