China’s burgeoning push to clean up its air in the future could warm the entire northern hemisphere by the end of the century by 0.1 degrees Celsius, making it even harder to keep the earth’s temperature below the (2.7 degrees Fahrenheit) limit that scientists say is necessary to prevent severe weather disruptions, increasing rainfall, rising sea levels, droughts and other dreaded effects of climate change by 2100.
Chinese officials saved the last 15 years by reducing air pollution from coal-fired power plants. But this public health campaign has an unfortunate side effect: The decrease in pollution helps warm the planet.
In fact, China’s burgeoning push to clean up its air in the future could warm the entire northern hemisphere by the end of the century by 0.1 degrees Celsius, making it even harder to keep the Earth’s temperature below the (2.7 degrees Fahrenheit) temperature limit that scientists say is necessary to prevent severe weather disruptions, more rainfall, rising sea level, droughts and other disastrous effects of climate change by 2100. This is because the same sulfur dioxide particles that come from coal combustion and cause respiratory problems in humans reflect sunlight which cools the planet.
In a new study published in the journal this week, a team of researchers from China and the United States used emissions data between 2006 and 2017, during China’s huge air pollution campaign. Through the installation of scrubbers and other new technologies on older coal plants and other factories, the country reduced sulfur dioxide emissions by 70 percent. The researchers then developed a computer model to predict how this change in air quality would affect something called “( ) — the amount of solar energy which is trapped in the earth’s atmosphere minus the energy that Earth reflects back to space.
The scientists used their model to simulate the pass through time of 150 years at both the higher emission rate of 2006 and the lower emission rate of 2017. Then they looked at what the temperatures would be after a century. The results show that the emission reductions will allow more energy to reach the Earth, leading to a total warming of about 0.1 degrees Celsius and not just where the pollution reductions occurred in China. This is because these sulfur dioxide pollutants are dispersed by wind currents and will be a result of a warming effect across the northern hemisphere.
It is one of these tradeoffs about which people have known before but we put some numbers on it, said Kelly Ramasy, professor of Earth System Sciences at UC Irvine and co-author of the new report.
There are also benefits to clean air. Tiny particles that come from coal emissions, automobile combustion and industrial plants enter the airways and run deep into the lungs, where they erode tissues and can enter the bloodstream. It can lead to an array of long-term and chronic health problems, from asthma to heart attacks. But from 2013 to 2017, China’s environmental control helped reduce premature deaths from respiratory disease, stroke, and lung cancer by nearly 10 percent, or about 200,000 people, according to this study released in the journal in 2019.