A new study published Monday (July 14) in Communications Earth and Environment reveals that efforts to reduce air pollution in East Asia have contributed to a faster pace of global warming.
Global warming—primarily driven by greenhouse gas emissions—has been accelerating over the past 15 years, causing record-high surface temperatures. During this same period, East Asian nations, especially China, have taken major steps to reduce air pollution to improve public health. In China alone, air pollution is linked to roughly 1 million deaths annually.
Sulfate Aerosols from Fossil Fuels Have Masked Some Global Warming by Reflecting Sunlight Away from Earth
However, certain air pollutants—particularly sulfate aerosols from fossil fuel combustion—have had a cooling effect by reflecting sunlight away from Earth’s surface. As a result, air pollution has unintentionally offset some greenhouse gas-induced warming.
The Intergovernmental Panel on Climate Change (IPCC) estimated in 2021 that aerosols reduced global surface temperatures by around 0.4 °C. That estimate, however, didn’t fully account for China’s significant air quality improvements beginning in the early 2010s.
According to lead author Bjørn H. Samset, a senior researcher at CICERO Center for International Climate Research, “We’ve been able to isolate the climate impact of East Asia’s air quality policies over the last 15 years. Our key finding is that the reduction in aerosols from East Asia has likely played a major role in the recent acceleration of global warming, as well as rising temperatures in the Pacific region.”
75% Drop in East Asian Sulfate Emissions Reveals Hidden Greenhouse Warming, Global Climate Models Show
Studying the climate impact of emissions from a single region is complex. It requires detailed climate simulations and up-to-date emissions data that accurately reflect pollution reductions, particularly in and around mainland China. Drawing on simulations from eight different climate models, this study demonstrates that a 75% drop in sulfate emissions from East Asia has partly exposed the underlying warming caused by greenhouse gases, altering temperature patterns across the globe.
Dr. Laura Wilcox, a contributing author and associate professor at the National Center for Atmospheric Science (NCAS) at the University of Reading, explained, “Air pollution’s climate effects are short-term, whereas carbon dioxide emissions have lasting impacts for centuries. So, while cutting air pollution may temporarily speed up warming, that effect is likely to be brief. We’ll see a spike in warming as the masking effect disappears, followed by a return to the typical greenhouse gas-driven warming rate once pollution levels stabilize.”
Read the original article on: Phys Org
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