Global warming could be worsened by cleaner airMarch 18, 2016
New studies reveal that cleaner air could actually accelerate the warming of the planet.
Two new studies, both recently released in the journal Natural Geoscience, have analyzed the powerful influence that aerosols have on the climate and suggest that as countries around the world make efforts to lower this type of pollution, global warming is worsening, because the elimination of this pollution appears to be resulting in more rapid warming than anticipated.
Certain aerosols have a temporary cooling effect on the atmosphere.
Although aerosols are definitely hazardous to the environment and human health, there are certain types of this emission – particularly sulfate – which scientists say can block solar radiation from breaking through to the planet’s surface. This can happen because sulfate and other similar aerosols scatter sunlight directly or help to increase the reflectivity and extent of cloud cover over the Earth. What results is a type of cooling effect, which is typically most present in areas with the heaviest pollution. Temporarily, this cooling effect can mask the perpetual warming effect caused by greenhouse gas (GHG) emissions in the atmosphere.
That being said, one notable fact about aerosols is that they usually have a short lifespan in the atmosphere. At some point, the rain will pull this pollution back out of the sky. On the other hand, if humans continually produce the emissions that send these fine particles or drops of liquid into the air, then it is likely that the cooling effect will appear constant.
However, what scientist have noticed is that as certain regions of the world begin to reduce their aerosol emissions, “regional brightening” is occurring, which is a term given to the phenomenon when the dimming effect on solar radiation starts to recede.
This acceleration of global warming could negatively impact the ability to meet climate goals made in last year’s Paris Agreement.
Nearly 200 countries were involved in the 2015 Paris Agreement and pledge to help in the fight against climate change by reducing emissions in the coming years. Based on the agreement, the countries will work together to keep the global temperature increase well below 3.6 degrees Fahrenheit. However, the findings of these new studies could make achieving this goal much harder.
The reason is that the researchers have noted that the “regional brightening” effect is already having a huge impact on certain parts of the world. Specifically, the paper discusses the impact European aerosol emission reductions are having on warming in the Arctic; a region of the world that is warming faster than others.
The researchers note that in regard to aerosol emission reductions, no other region in the world has reduced these emissions over the past several decades as much as Europe. Since this is the case, Europe’s policies have probably had the largest effect on climate change linked to aerosol.
“It seems like our aerosol particles have somehow masked the amplified Arctic warming, and as greenhouse gas concentrations continue to increase, it’s going to take over — basically, it’s going to warm more and more in the Arctic,” said Stokholm University professor of meterology and the paper’s senior author, Annica Ekman.
Now, with more and more regions of the world cutting down on their use of aerosols (a process crucial to improve air quality and protect human health worldwide), it is likely that “regional brightening” will occur in other areas of the globe, as global warming continues to increase.
Sadly, this makes a lot of sense as pollutants can and do reflect sunlight back into space. Fortunately, the answer is to keep pollution levels high but to reduce greenhouse gas emissions.