How Aerosols Brighten Clouds — and Cool the Planet | Sarah J. Doherty | TED

Tutorial: Understanding the Impact of Aerosols on Climate Change

Step 1: Introduction to Aerosols and Climate Impact

• Humans have been adding a significant amount of particulate pollution, known as aerosols, to the atmosphere, contributing to global warming and causing health issues.
• Efforts are being made to reduce emissions of these aerosols to improve air quality, but this may unintentionally accelerate climate warming.

Step 2: How Aerosols Cool the Climate

• Aerosols in the atmosphere absorb sunlight and increase the reflection of sunlight away from the planet, leading to a cooling effect.
• Aerosols scatter sunlight back to space and make clouds brighter or more reflective, further cooling the climate by about half a degree Celsius.

Step 3: Impact of Cleaning Up Aerosols

• As efforts are made to clean up the air and reduce aerosol emissions for human health, the cooling effect of aerosols diminishes quickly as they only last in the atmosphere for about a week.
• Unlike greenhouse gases that continue to warm the planet for decades to centuries.

Step 4: Uncertainties in Aerosol's Cooling Effect

• The exact cooling effect of aerosols can vary and is uncertain, ranging from half a degree to almost a full degree Celsius.
• Understanding how aerosols cool the climate and the uncertainties involved is crucial for climate research.

Step 5: Potential Solution - Marine Cloud Brightening

• One potential solution to reduce climate warming is through marine cloud brightening, where natural aerosols like sea salt are added to clouds to mimic the cooling effect of pollution aerosols.
• Computer models suggest that brightening a fraction of clouds over the ocean can significantly reduce climate warming from greenhouse gases.

Step 6: Challenges and Research

• Detailed studies and better real-world data are needed to understand the interactions between aerosols and clouds for effective climate modeling.
• Developing instruments like the Cloud Aerosol Research Instrument to generate tiny sea salt aerosols for controlled aerosol studies is a significant technological challenge.

Step 7: Importance of Research and Collaboration

• Collaborative research and openness in sharing findings are essential for better understanding the impact of aerosols on climate change.
• Engaging with marginalized communities and researchers globally is crucial for informed discussions on climate risks and potential solutions like marine cloud brightening.

Step 8: Conclusion

• Marine cloud brightening is not a solution to the climate crisis but could help mitigate the symptoms of excess heat in the atmosphere and ocean.
• Continued research and understanding of aerosols' role in climate change are vital for addressing the challenges of a rapidly warming climate.

By following these steps, you can gain a comprehensive understanding of how aerosols impact climate change and the potential solutions being explored to address these challenges.