The world is warming up and it’s happening faster

NEW YORK - Summer started barely a week ago, and already the US has been smothered in a record-breaking “heat dome”.

Alaska saw its first-ever heat advisory in June. And all of this comes on the heels of 2024, the hottest calendar year in recorded history.

The world is getting hotter, faster. A report published last week found that human-caused global warming is now increasing by 0.27 deg C per decade. That rate was recorded at 0.2 deg C in the 1970s, and has been growing since.

This does not surprise scientists who have been crunching the numbers. For years, measurements have followed predictions that the rate of warming in the atmosphere would speed up. But now, patterns that have been evident in charts and graphs are starting to become a bigger part of people’s daily lives.

“Each additional fractional degree of warming brings about a relatively larger increase in atmospheric extremes, like extreme downpours and severe droughts and wildfires,” said Dr Daniel Swain, a climate scientist at the University of California.

While this aligns with scientific predictions of how climate change can intensify such events, the increase in severity may feel sudden to people who experience them.

“Back when we had lesser levels of warming, that relationship was a little bit less dramatic,” Dr Swain said. “There is growing evidence that the most extreme extremes probably will increase faster and to a greater extent than we used to think was the case,” he added.

Take rainfall, for example.

Generally, extreme rainfall is intensifying at a rate of 7 per cent with each degree Celsius of atmospheric warming. But recent studies indicate that so-called record-shattering events are increasing at double that rate, Dr Swain said.

“There is no weather that is happening outside of climate,” said Dr Kate Marvel, a climate scientist and author of the book Human Nature.

“This is stuff that is manifesting in the real world,” she said, citing catastrophes such as Hurricane Helene that hit Florida in 2024.

According to Dr Swain, scientists have yet to come to a universal understanding of these events, in part because the infrequent nature of outliers makes them difficult to study.

And as warming has intensified, so have the impacts on vulnerable regions of the planet, such as the Arctic and Antarctic, making previously rare or hidden consequences more apparent.

Scientists are fine-tuning their models to understand the behaviour of the vast ice sheets in such places to match the rapid changes they are observing.

In March, a Nasa analysis found that sea levels had risen faster than expected in 2024, in part because of a combination of melting glaciers and heat penetrating deeper into oceans, causing them to expand thermodynamically.

Sea surface temperatures are rising faster than previously predicted, too, according to a study published in April by researchers at the National Centre for Earth Observation in Britain.

Climate science professor Cecilia Bitz of the University of Washington said that modelling the earth is complex, and that there are an innumerable amount of small factors that could be taken into account.

But even with these uncertainties, scientists have ways of building their models to identify trends that are largely accurate.

“Nothing is defying our big picture about the physics of the climate system,” Prof Bitz said.

Overall atmospheric warming has consistently followed modelling predictions for decades. But recently, the fundamental imbalance responsible for this heat has been tilting – catching even scientists off guard.

Global warming is a symptom of Earth’s energy imbalance, which is a measure of the difference between the total amount of heat reaching Earth from the Sun, and the amount radiating back into space.

In May, a paper analysing data from a Nasa satellite found that this imbalance had grown faster than expected, more than doubling in the past two decades and becoming nearly twice as large as it was previously predicted to be.

Dr Zeke Hausfather, a research scientist at Berkeley Earth, said climate scientists were still working to understand these findings.

There are various theories, such as fewer emissions of aerosols, a type of air pollution that is harmful to human health and that increases the reflectivity of clouds, which bounce the Sun’s heat back into space.

Historically, aerosol emissions have masked the warming effect of greenhouse gases like carbon dioxide. Over the past half-century or so, as nations reduced certain kinds of air pollution, aerosol emissions fell significantly.

According to Dr Hausfather, this change is the primary reason atmospheric warming has accelerated in recent decades.

But the most worrying possibility behind Earth’s energy imbalance, he said, is how the general nature of clouds may be changing in response to climbing temperatures. It is a feedback loop that could potentially exacerbate warming and is “one of the single biggest uncertainties in predicting future climate”, he said.

As the world continues to emit planet-warming greenhouse gases, and temperatures climb past what the human world was built to handle, Dr Marvel said, more people will experience climate change in damaging and frightening ways.

“It is always worse than expected when it happens to you,” Dr Marvel said. “It is one thing to see something in a climate model, and it is a totally different thing to actually experience it in your own life.” NYTIMES