A new study by Norway’s CICERO climate institute finds that China’s efforts to curb sulphur pollution from coal plants, vehicles, and industries over the past two decades may have inadvertently sped up global warming.
The research estimates that global temperatures rose by around 0.07°C due to reduced sulphur emissions, particularly since 2010. Sulphur dioxide (SO₂) converts into sulphate aerosols in the atmosphere, which cool the planet by reflecting sunlight and enhancing cloud formation. Cutting these emissions removes that cooling shield, revealing the full impact of greenhouse gases.
Triggered by public outcry ahead of the 2008 Beijing Olympics, China fitted scrubbers on coal plants and tightened vehicle emission norms—achieving a 75% reduction in sulphur emissions. While this improved air quality and public health, it also removed a layer of atmospheric cooling, contributing to the rise in global temperatures.
Lead author Bjørn Samset explained to New Scientist, “The warming was always there—we just had some artificial cooling from pollution. Removing it has exposed the real impact.”
This study is the first to precisely model the atmospheric effects of China’s pollution cuts.