Around 7 million people are killed by air pollutants Each year. This pollution is mainly tiny particles suspended within the air, which can be inhaled and cause respiratory problems. HeartAnd lungBoth diseases and Cancer.
These small particles can also create clouds in the atmosphere, whether they’re crystals of sea salt or sulfate from industrial chimneys. These particles collectively are known as aerosols.
Only aerosols can condense moisture in the atmosphere into cloud droplets. These aerosols, which are produced by fossil fuel combustion, make the droplets larger and more reflective of sunlight. They can also last longer.
This causes more sunlight to scatter back into space than is absorbed by the Earth. This is why the Intergovernmental Panel on Climate Change(IPCC) ConcludedThe cooling effect of human-made aerosols on the climate can help reduce greenhouse gas emissions and some of their warming.
Although this may sound good news, there is no reason to celebrate. The cooling effects of aerosols are short-lived. Although the CO2The emissions from coal power stations and cars today will still be in the atmosphere centuries laterThe aerosols that were emitted from air pollution will no longer have any influence in a month.
This means that once we stop emitting aerosols their buffering effects on climate change vanishes. Meanwhile, the greenhouse gases will continue to heat the planet.
Und in Research in progressWe found that air pollution may have a greater effect on clouds’ reflectivity than we had previously thought.
Delegates gathered in Sharm El-Sheikh to discuss COP27, which is the most recent version of the Convention on Climate Change. UN climate change summitTo reduce fossil fuel combustion, they must work harder.
Aerosols’ effect on the clouds
We used data about ship emissions to calculate the effects of human-emitted airsols on climate. Because ship emissions pollute relatively clear air, it is easier to study the effects in isolation.
Satellite images show aerosols that ships emit as long white streaks, called ship tracks. Our data suggests that less than 5% of this pollution can be seen.
Our study was based on a global database that contains more than 2,000,000 ship routes over six years.
Combining this with weather forecasting models, they were able to simulate where the emissions are carried by wind and enter clouds. This allowed us to study aerosol effects even though no ship tracks were visible.
We used satellite data to measure the droplets in polluted clouds and the water content.
We found that ship emissions – even when invisible in satellite images – make nearby clouds more reflective. This is partially due to invisible ship emissions, which make up the vast majority of cloud water content.
Previous estimatesIt was suggested that ship emissions could dry out clouds. Scientists are therefore likely to underestimate the extent of air pollution’s cooling effect.
The same could be true for aerosols generally: A higher level of pollution may cause clouds to brighten more than previously known, which can lead to a greater cooling effect. These results will need to be applied to all types of air pollution. Scientists still need to conduct more research.
Another Recent studyOur research group offered a glimpse into a future without as much air pollution.
We used computer algorithms to find visible ships tracks in satellite images. RegulatedThe International Maritime Organization introduced them in 2020 to reduce air pollution caused by global shipping.
The resultant reduction in ship pollution led to a 25 percent decrease in the visibility of brighter and more reflective clouds on ship tracks. This shows how air pollution can unintentionally increase the climate.
Climate action and pollution
Regulating air pollution is not easy. Not at oddsProtecting the climate. In many cases, both can be achieved by eliminating their common cause. fossil fuels.
That means that the transport sector should reduce its use of fossil fuels. It does not mean that they need to apply better filters to their exhaust pipes. Similar arguments can also be made in the case of industry, electricity generation, or heating.
Overall, scientific understanding of air pollution and climate change compels us to end the burning of fossil fuels – both for human health and for the planet.
Peter ManshausenDr. Candidate in Atmospheric Physics University of Oxford; Duncan Watson-ParrisSenior Research Associate in Atmospheric Physics University of Oxford?, and Philip StierProfessor of Atmospheric Physics. University of Oxford
This article was republished by The ConversationUnder a Creative Commons License Please read the Original article.
