Reducing Aerosol Emissions Aids in Global Water Preservation
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A new essay co-authored by climate and atmospheric scientist Veerabhadran Ramanathan and political scientist David G. Victor of UC San Diego, along with Jessica Seddon, highlights the urgent need for policymakers to address the impact of aerosol emissions on climate change.
The essay, titled "The Next Front on Climate Change: How to Avoid a Dimmer, Drier World," appears in the March/April 2016 issue of Foreign Affairs. In it, the authors argue that avoiding dimming, which requires significant cuts in aerosol emissions, should be a top priority for policy makers.
Dimming refers to the reduction of sunlight due to aerosol particles in the atmosphere. These particles, such as black carbon and organic aerosols, have a profound effect on the water cycle, leading to decreased rainfall and even drought. Rapid industrialization in East and South Asia, for example, has resulted in 10 to 15 percent less sunlight and a 7 percent decrease in average annual rainfall due to an increase in sulfur dioxide and black carbon.
Aerosols not only cause immediate and localized harm, but also have distinct effects beyond higher temperatures. Some aerosols absorb sunlight before it reaches the Earth's surface, while others reflect it back to space, dimming the planet. The focus on aerosols by policymakers has been predominantly on their cooling effect, not their impact on sunlight and rainfall. Policymakers have often overlooked the fact that aerosol emissions disrupt natural processes of evaporation at ground level.
To address this issue, the authors propose three specific actions. First, they recommend pushing for cleaner and more efficient technology for energy production. This includes promoting renewable energy sources and implementing stricter emission standards for power plants.
Second, the authors suggest tightening regulations on transportation systems. This includes promoting electric vehicles, improving public transportation, and implementing stricter emission standards for cars and trucks.
Third, the authors recommend reducing or eliminating the use of dirty fuel in households. This includes promoting clean cookstoves, improving fuel quality, and implementing policies to phase out the use of high-polluting fuels.
The benefits from these efforts to control aerosol pollution can be quickly seen due to the short lifetimes of these pollutants in the atmosphere. Countries must also prepare to adapt to the changes that will inevitably occur due to climate change.
The Paris Climate Conference in 2015 resulted in a landmark accord, but the authors argue that more needs to be done to address the issue of aerosol emissions. The reduction of pollutant aerosols is recommended to play a central role in nations' environmental policies.
By reducing aerosol emissions, countries can not only "dramatically limit the risk of droughts and irregular monsoons," but could reduce global dimming within an estimated 10-20 years. This would help to avoid a "dimmer, drier world" and ensure a more stable and sustainable future for all.
- The authors of the essay, titled "The Next Front on Climate Change: How to Avoid a Dimmer, Drier World," suggest that policymakers should focus on the environmental-science aspect of aerosol emissions to reduce the impact on climate change, health-and-wellness, and the environment.
- To supplement the Paris Climate Conference's accord, the authors propose the reduction of aerosol emissions as a crucial strategy in the health-and-wellness, scientific, and environmental-policy agendas, as it could help prevent a "dimmer, drier world" and ensure a sustainable future by reducing global dimming within an estimated 10-20 years.
