Why cleaner air is contributing to global warming

Photo: Pixabay/Hugo_ob

Climate change solutions continuously adapt as scientists learn more about the causes of global warming. Initially, many thought that removing all foreign substances from the air would have the effect the planet needs. Unfortunately, it’s starting to look like this is not the case.

Does clean air cause global warming?

It’s natural to think that removing all synthetic compounds from the air is the solution to global warming. In some cases, this is true; methane, nitrous oxide, and carbon dioxide are all causing the greenhouse effect currently heating the planet to unsafe levels. Their presence in the atmosphere has risen dramatically since 1750, primarily due to human activity.

However, some pollutants have been helping cool Earth down. As scientists have recently discovered, aerosols are quite beneficial. Natural ones like ash, pollen, and dust reflect sunlight into space, keeping it from excessively heating the planet. They also help clouds form more water droplets, which cools things down as well.

The problem lies in artificial aerosols and high amounts of toxic natural ones. Formaldehyde, methylene, and benzene are frequently present in household products and pose long-term dangers. These severely diminish air quality over time and can cause damage to the respiratory and central nervous systems, kidneys, and liver.

However, early demands for clean air caused scientists to focus on removing all aerosols. They were successful in this; aerosol emissions have declined worldwide in recent years. But this is not all good news. This reduction has actually contributed to warming the planet by reducing how much the clouds can produce water droplets. In addition, the atmosphere is missing out on its reflective properties.

At the height of the COVID-19 lockdowns, people were emitting less because they could not drive and production at large, highly polluting factories slowed. While this should be a great thing, it meant they were releasing fewer aerosols. In turn, the planet’s temperature rose by between 0.1° and 0.3° Celsius.

What to do about aerosols?

Research is currently unclear as to how much aerosols truly cool planet Earth. However, it is possibly one of the most important aspects of figuring out climate change.

Human-made emissions of this nature have a deleterious effect on the population’s physical health. Vehicles, coal, and smokestacks pumping out thick black smoke kill over 4 million people yearly. However, getting rid of them overnight would likely cause the planet’s temperature to rise significantly.

Could the answer be to add more natural aerosols to the atmosphere? They are proving to be a bit helpful, after all. While greenhouse gases will reside in the air for hundreds of years, aerosols disappear in around a week or so, possibly making them less harmful.

By reducing manufactured emissions and increasing natural emissions, more aerosols could potentially be the answer climate scientists are looking for.

But other research has pointed out the negative effect of too many aerosols. Researchers at MIT say increasing these emissions could change storm and wind patterns for the worse. While weaker storms could be beneficial in some scenarios, it could become dangerous when more aerosols reduce rainfall and much-needed breezes.

Another outcome identified by their model was flipping the temperatures of the poles and the equator.

What is the solution?

Since even human-made aerosols are reducing Earth’s temperature, is the solution to not change our current habits? Not necessarily.

Air pollution does increase the global temperature and climate change rates. Greenhouse gases are still the current problem requiring people to curb their emissions and find sustainable solutions. While unnatural aerosols contribute to cooling effects, they are often comorbid with harmful pollutants.

Additionally, they are detrimental to human health.

But cutting them out altogether could be damaging in the long run. Studies show eliminating sulfate – which can be natural or human-made – could add half a degree to current levels of global warming.

Overall, it will take more research to determine what adding more natural aerosols to the environment would do. While it is vital to lower emissions, some aspects of pollution are helping mitigate the effects for the time being.

For now, the solution should be to eliminate greenhouse gas emissions wherever possible. People need to redouble their efforts to reduce carbon dioxide, nitrous oxide, and methane so the planet won’t need as much cooling.

While natural aerosols can be beneficial, the ones occurring with pollution may be less necessary if people focus on increasing their sustainability.