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Heat wave map graphing its duration and magnitude according to different forcing simulations: only greenhouse gases decrease (GHG2050). Aerosols and greenhouse gases are both reduced (AerGHG2050). Tropospheric ozone, aerosols, and greenhouse gases will all decrease by 2050 (ALL2050) and 2100 (ALL2100). Credit: Wang et al. 2023.
Climate models based on Earth’s current trajectory of greenhouse gas emissions predict a worst-case scenario of global warming of 4.3°C by 2100 if sufficient action is not taken. The Paris Climate Agreement has been adopted by 195 countries and states, and aims to limit global temperature rise to 2°C (and preferably 1.5°C) above pre-industrial levels by 2100. The Intergovernmental Panel reports 1.1°C. Increased by 2020.
The comprehensive study also argued that to reach this 1.5°C target, greenhouse gas emissions must peak by 2025 and then decline by 43% over the remainder of this century.
While implementing strategies to combat greenhouse gas emissions and achieve carbon neutrality by 2025 is a key focus, new research was published in 2020. nature communications outlined the ever-pressing issue of atmospheric aerosols and their adverse effects on climate warming.
Moreover, research by Associate Professor Pinya Wang and colleagues at China’s Nanjing University of Information Science and Technology highlights an increase in the frequency and intensity of extreme weather events (from floods to heat waves) and their consequences in the future. There is. Based on increases in global surface temperature and average annual precipitation, it could increase by 0.92 °C, or 0.10 mm per day, by 2100.
Using a community Earth system model, the research team found that reductions in atmospheric aerosols have a negative impact on the Earth’s climate, making extreme weather events worse than greenhouse gases or changes in the tropospheric ozone layer (up to 10 km above the ground). It was determined that
Nevertheless, the three are intricately linked, and Wang et al. They point out that the production of pollutants is also reduced.
This ozone is formed by chemical reactions in exhaust gases from vehicles and chimneys, and often appears in the form of smog that pervades urban areas, with Dammam in Saudi Arabia recently topping the list of problematic air particle pollution. It has been.
China is often cited as a smog-prone country, and recent studies have shown that vehicle and smokestack emissions of sulfur dioxide, nitrogen oxides, primary particles less than 2.5 μm in diameter, and volatile organic compounds We found that we needed to reduce it by 93% in real terms. %, 90%, and 61% to achieve carbon neutrality by 2060, respectively.
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The spatial distribution of annual mean surface air temperature changes according to the modeled scenario. a) Carbon-neutral greenhouse gas emissions by 2050. b) Reduce aerosols by 2050. c) Reduce greenhouse gases, aerosols and ozone by 2050. d) Combined in 2100. Credit: Wang et al. 2023.
Tropospheric ozone affects Earth’s temperature by increasing radiation power and trapping more solar radiation, whereas aerosol particulates can have the opposite effect (for example, sulfates cool and black carbon warms). Scientists cited recent research highlighting the impact of the coronavirus pandemic on extreme weather events, saying lower aerosol emissions led to warmer temperatures and lower humidity, resulting in more mountains in the U.S. in 2020. It is said that the number of fires has increased.
The research team modeled forcing from each of greenhouse gases, ozone, and aerosols under a carbon-neutral common socio-economic pathway 1-1.9, with carbon dioxide concentrations peaking at 437 ppm by 2050 and by 2100. The amount of methane will drop to 1,061ppb from the current 1,884ppb. ppb by the end of this century. Under this same scenario and time frame, sulfur dioxide emissions would also decrease from his current 3gm.−2be−1 up to 1g−2be−1black carbon starts from 1g−2be−1 up to 0.1g−2be−1 Organic carbon 0.2gm−2be−1 up to 0.14 grams−2be−1.
Compared to a 2020 baseline, based on greenhouse gas emissions alone, Wang et al. show that increasing radiative forcing will lead to an overall increase in global surface air temperatures by 2050, with a peak estimated that the temperature would reach 0.2°C over Greenland.
However, when aerosols were included, global surface air temperatures increased significantly in the model, reaching up to 2°C across mid-high latitudes in the Northern Hemisphere, but this was adjusted by a small decrease due to the contribution of tropospheric ozone. may be. Until 2100, surface temperatures are expected to continue to rise due to global warming due to a decrease in aerosols.
Similarly, the model identified changes in global annual mean precipitation under the same forcing and found that precipitation in the tropical oceans (particularly the western Pacific) increased under greenhouse gas-only forcing. . Adding aerosol reduction to the simulation worsened rainfall across the Northern Hemisphere, but had the opposite effect across the Southern Hemisphere, where tropospheric ozone reduction had little effect.
South Asia, East Asia, and Southeast Asia are modeled to see the greatest increase in precipitation, reaching 0.3 mm per day. This pattern remains the same throughout the rest of this century, but with larger amplitude. This is due to an increase in water vapor in the atmosphere due to increased temperature, which promotes evaporation and therefore increases specific humidity.
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Extreme precipitation maps of global heavy rainfall amount and duration based on different forcing simulations: greenhouse gases only decrease (GHG2050). Aerosols and greenhouse gases are both reduced (AerGHG2050). Tropospheric ozone, aerosols, and greenhouse gases will all decrease by 2050 (ALL2050) and 2100 (ALL2100). Credit: Wang et al. 2023.
Combining these extreme temperature and precipitation models, we estimate a heat wave with greenhouse gas-only forcing lasting 5 days per year, 4 days per event, and a daily temperature increase of 0.25°C. It was used to simulate frequency and magnitude.
However, if we include the decline in aerosol abundance, significant worsening of heatwave intensity would occur for more than 40 days a year, each lasting 20 days, and global temperatures would rise by 0.75°C per day by 2050, modeled it was done. In this century, this figure has increased further, with 50 days per year experiencing heatwave conditions, with individual events lasting 28 days and daily temperature fluctuations of 1.5°C.
This research aims to reduce not only greenhouse gas emissions but also the pollution associated with them, in order to give the world a chance to achieve ambitious goals and reduce the huge environmental, economic and social impacts of global warming. It highlights the continued need to find more sustainable solutions to also tackle materials. It can be triggered for decades and generations to come.
For more information:
Pinya Wang and others say aerosols will overtake greenhouse gases, causing climate warming and an increase in extreme weather events as we move toward carbon neutrality. nature communications (2023). DOI: 10.1038/s41467-023-42891-2
Magazine information:
nature communications
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