Is China’s Air Pollution Fight Aggravating Climate Change?

Aerosols are tiny particles or droplets suspended in the air that can either cool or warm the climate, depending on their type and colour. While many people associate aerosols with spray cans—such as insect repellent or spray paint—the scientific definition is much broader.

Aerosols occur naturally, such as smoke from wildfires, volcanic gases, or salty ocean spray. Human activities, including the release of soot and pollution from burning fossil fuels, also produce them.

Their effect on the climate depends largely on colour: light-coloured aerosols reflect sunlight, leading to a cooling effect, while dark-coloured aerosols absorb heat, contributing to warming. Due to their dual role, aerosols are a central focus of climate change research.

Aerosols and Climate Change Research

Scientists are deeply interested in aerosols because of their complex and sometimes contradictory impacts on Earth’s temperature. While some aerosols offset global warming by cooling the planet, others amplify it. This variability makes them one of the most uncertain factors in climate models.

A study in Communication Earth and Environment, “East Asian aerosol cleanup has likely contributed to the recent acceleration in global warming”, published on 14 July 2025, reveals that efforts to reduce air pollution in East Asia may inadvertently cause climate warming.

Countries like China have started to implement strict air quality polices to address air pollution, which has been a significant cause of premature deaths, killing around a million people annually.

However, this link between global warming and the reduction of air pollution in East Asia has not been proven yet. To examine the link between these two trends, the study used simulations from eight Earth System Models.

The research finds that China’s policies to combat air pollution have reduced sulphur dioxide emissions by 75% over the last 15 years. This reduction of sulphate emissions from East Asia has led to an additional warming of 0.07°C, which helps explain the rise in global warming rates since 2010.

Sulphate aerosols emitted by the burning of fossil fuels serve as an artificial sunshade, helping to cool the air by reflecting sunlight into space.  The IPCC estimated in 2021 that air pollution leads to approximately 0.4°C of global cooling.

The study also found that areas warming the most correspond to regions where there is a reduction in sulphur dioxide emissions from East Asia, particularly China. Satellites also observed an increase in TOA radiative imbalance in this same area, meaning that more energy is trapped here by GHG gases, causing warming. 

This observation supports the idea that China’s recent push to reduce air pollution and improve residents’ health has highlighted the warming caused by GHG emissions that contribute to the recent increases in global temperatures.

In the future, it is projected that sulphur dioxide emissions from East Asia will continue to decline, but at a slower pace. Recent estimates indicate that there are fewer than 10 million tons of SO₂ emissions remaining to be cut, or approximately 25% of the 2010 levels.

This means future reductions in East Asian pollution will likely have a negligible effect on climate warming rates. However, the extent of their impact still depends on how aerosols interact with clouds and the climate, a relationship that scientists are still trying to understand fully.