Rapidly reducing aerosol emissions that are part of air pollution without simultaneously reducing greenhouse gas emissions could lead to a sudden acceleration of warming and extreme heat in highly polluted areas such as India. The researchers are study Published in November 2024 Geophysical Research Letter.
The analysis found that in the late 20th century areas with clean air increased more over time, while the densely populated population development index experienced lower warming levels due to the masking effect of pollution.
According to Aditya Sengupta, a graduate researcher at the University of Melbourne, a graduate researcher.The authors of this study’s sudden cessation of aerosol emissions could also increase the rate of warming on a time scale.
The study is particularly relevant to India, which is currently working to improve air quality while trying to get rid of the worst climate change on the other hand.
Greenhouse gas vs. aerosol
Global warming is caused by the accumulation of greenhouse gases in the atmosphere, and is well known to be extreme in temperature and rainfall. Aerosols can somehow offset the effects of greenhouse gases.
This is because, while greenhouse gases capture trap heat and warm the earth’s surface, aerosols such as sulfates and nitrates spread solar radiation to prevent it from reaching the ground and having a cooling effect. Aerosols can also affect the water cycle.
Greenhouse gases are also filled with mixing in the atmosphere. As a result, their effects can be felt around the Earth, including the door knocking effect in the climate. On the other hand, the concentration of aerosol in the atmosphere varies by location and time. Greenhouse gases also have longer lifespans – carbon dioxide can persist in the atmosphere without rupturing for hundreds of years – while aerosols last for days to weeks at a time.
Therefore, the consequences of changes in atmospheric aerosol load can be felt almost immediately.
heat
Growing economy and industrialization go hand in hand with emissions of aerosols and fossil fuels, according to Govindasamy Bala, professor at the Centre for Atmospheric and Ocean Sciences, Indian Academy of Sciences, Bangalore.
In India, thermal power plants generate about 70% of the country’s electricity by burning coal, which contains a certain amount of sulfur. “So before the smoke [exhaust gas from the combustion process] Released into the atmosphere, you must remove sulfur dioxide from the source to reduce air pollution. ” Bala explained.
According to Bala, sulfate aerosols are formed by the oxidation of sulfur dioxide, accounting for nearly 50-60% of the overall aerosol composition in India, in addition to black carbon, dust and other pollutants.
Invisible Offset
“[O]Ur’s digital display, if not for aerosols, we would be bigger in India’s warmth, IIT-Delhi said.
According to him, India’s temperature was about 0.54°C between 1906 and 2005, with about 2°C due to warming of greenhouse gases, while other anthropogenic factors had a cooling offset of about 1.5°C. And most of the cooling may come from the Aerosols released by human industrial activities.
According to the history of Assessment of climate change in India The country’s average temperature was published in 2020 by the Ministry of Earth Sciences at around 0.7°C between 1901 and 2018, largely due to greenhouse gas-induced warming, but partly offset by artificial aerosols and land use changes.
For comparison, overall long-term global warming is currently higher than 1.3°C in the pre-industrial era.
Aerosols and rain
The effect of aerosols on rainfall is another matter: “Generally, the temperature effect is fairly simple: remove the aerosol, warm it up,” Achutarao said. “With precipitation, things get more complicated.”
According to Barra, the global average cooling was about 0.6°C during the industrial period due to aerosols. But he said that because the recent climate change range panel (IPCC) reports, “This cooling is uneven – in the Northern Hemisphere, it cools at 0.9° and in the Southern Hemisphere, it is about 0.3°C. Since this larger cooling in the Northern Hemisphere is this larger cooling in the Northern Hemisphere, the actual aerodynamic effect is a small amount of the Monomon Mountains.”
He added that many people want to understand the effects of aerosols emitted in India on India, but the long-range impact of aerosols is also important. For example, May 2024 study Posted in Proceedings of the National Academy of Sciences The extreme heat wave incidents in the Pacific on the west coast of North America became worse, the report said.
Similarly, according to ongoing research by Bala, any significant increase in Indian aerosols could have a negative impact on the hydrological cycle and reduce monsoon rainfall. Understanding this process is an active area of global research.
Net zero is not the end point
Aerosol pollution and greenhouse gas-related climate pollution are both mainly due to large-scale industrial activities. While warming caused by greenhouse gases increases the risk of extreme heat, aerosols can cause respiratory diseases, which can have more complex effects on vulnerable groups, Sengupta said.
The study found that cutting both also requires policies to support people at risk who have suddenly increased warming in the short term.
“Achieving zero carbon emissions is not the end of the story, and policymakers should focus on long-term adaptation policies in vulnerable parts of India, especially those living in India-leaning plains, where the highest aerosol loads were found.”
However, due to the high aerosol distribution, it is difficult to accurately predict how specific locations in India will be affected when (and whether) the aerosols are cleaned.
Experts believe that the most reliable step is to develop a better thermal action plan. Sustainable Futures Cooperation, a Delhi-based research organization, recently reported that few of the hot-action action plans in nine cities – Delhi, Mumbai, Bangalore, Faridabad, Guario, Gota, Kota, Ludhiana, meerut and surat – include long-term actions, or even poorly targeted actions. If and when the aerosol is removed from the atmosphere, the thermal stress in these cities may worsen.
Bala added: “While clean air may accelerate sustained warming by uncovering greenhouse gas-induced warming, this may be beneficial in terms of increasing rainfall in India. These trade-offs should be considered when evaluating the impact of aerosols on our complex climate systems.”
Having said that, all experts agree that the direct benefits of reducing air pollution far outweigh any adverse consequences due to higher heat or rainfall damage.
Neelima Vallangi is an independent journalist and film producer covering climate change in the Himalayas and South Asia.
publishing – April 3, 2025 at 05:30 am IST
