New research shows that cleaner air in East Asia, particularly due to China’s aggressive emission cuts, has contributed to notable global warming over the past 15 years. Learn how this surprising discovery is shaping our understanding of climate change.
One of the most pressing mysteries in climate science — why Earth has warmed faster over the last 15 years — might have a surprising answer. Cleaner air in East Asia, especially in China, could be driving this accelerated warming, according to a groundbreaking international study published in Communications Earth & Environment.
The research, conducted by a team of international scientists, reveals that reductions in aerosols in East Asia have contributed about 0.05 degrees Celsius per decade to global temperatures since 2010, shaping much of the recent acceleration in warming.
This trend accounts for most of the observed warming increase even after considering natural fluctuations like El Niño.
“When something like the anomalous, record-breaking warmth of 2023 and 2024 happens, climate scientists start to wonder if there’s a factor we’re missing,” co-author Robert Allen, a climatology professor at the University of California, Riverside, said in a news release. “This study was our effort to figure out what that might be.”
Lead author Bjørn Samset, a senior researcher at the Center for International Climate and Environmental Research in Norway, elaborated on the findings.
“The spike in warming,” he added, “aligns with a dramatic drop in aerosol pollution from China’s skies.”
The study utilized simulations from eight major climate models, drawing data from the Regional Aerosol Model Intercomparison Project (RAMIP), which included contributions from modeling centers across the United States, Europe and Asia.
Since 2010, China has aggressively targeted air quality, cutting sulfur dioxide emissions by approximately 75%.
While these policies have significantly reduced pollution, which was a leading cause of premature death in China, they have also removed significant amounts of cooling aerosols from the atmosphere, leading to intensified warming, particularly over East Asia.
This region could face more extreme heat, altered monsoon patterns and potential disruptions in agriculture as a result.
This kind of cleanup is a double-edged sword, according to Allen.
“Reducing air pollution has clear health benefits, but without also cutting CO₂, you’re removing a layer of protection against climate change,” he added. “It highlights the need for parallel efforts to improve air quality and reduce greenhouse gas emissions.”
Aerosols, being short-lived atmospheric particles, have caused a temporary spike in global temperatures which may subside soon, Allen explained.
“Sulfur dioxide and sulfate aerosols have lifetimes of about a week. Once they’re removed, we’ll eventually settle back into a warming rate that’s more consistent with the long-term trend,” he added.
The study also emphasizes that long-term climate change is primarily driven by carbon dioxide and methane.
“Our study focused on the recent, dramatic speedup in global warming, which is very concerning but still small compared to the overall, long-term amount of warming from increased CO₂ and methane,” added Samset.
With other regions, including South Asia, Africa and North America, also initiating efforts to reduce aerosol emissions, RAMIP researchers plan to analyze how these changes might influence future climate trends.
In light of these findings, some scientists have proposed replicating aerosol cooling by injecting particles into the stratosphere. However, Allen advises caution.
“It’s a card we might have to play if we’re pushed into a corner,” he added. “But it comes with a host of risks, including disrupted rainfall patterns, food insecurity and political tensions.”
The study underscores the necessity of dual-focus strategies for tackling climate-related challenges.
“Air quality improvements are a no-brainer for public health,” Allen concluded. “But if we want to prevent the worst impacts of climate change, we have to cut CO₂ and methane too. The two must go hand in hand.”