Trap or solution? Is solar geoengineering a viable solution for mitigating global warming?
Have you ever heard about solar geoengineering? Probably, if you work in the field of geoengineering or maybe in agriculture. Is this a solution for global warming? We discussed these options in a previous article, but we didn’t provide much explanation. Here we are with some additional insights, as the topic is indeed interesting.
Solar geoengineering (also known as solar radiation management – SRM) refers to a set of theoretical techniques to cool the Earth by reflecting a portion of sunlight into space. These techniques aim to mitigate some of the warming caused by greenhouse gases, particularly carbon dioxide (CO2), which trap heat in the Earth’s atmosphere. Solar geoengineering does not address the root cause of climate change—excess greenhouse gas emissions—but instead seeks to reduce the symptoms of global warming by manipulating the amount of solar energy reaching the planet. It is often considered a temporary or emergency measure to buy time while pursuing emissions reductions.
Key Solar Geoengineering Techniques:
- Stratospheric Aerosol Injection (SAI): This method involves releasing tiny reflective particles (such as sulfur dioxide) into the stratosphere. These particles scatter sunlight, reducing the amount of solar energy that reaches the Earth’s surface.
- Marine Cloud Brightening (MCB): This technique involves spraying fine particles, such as sea salt, into low-lying marine clouds to increase their reflectivity. The brighter clouds would reflect more sunlight into space, reducing the heat absorbed by the oceans and atmosphere.
- Cirrus Cloud Thinning: Unlike other methods, this approach explicitly targets high-altitude cirrus clouds, which are known to trap heat. By thinning these clouds, the Earth could radiate more heat into space, cooling the planet.
Potential Benefits:
- Rapid Cooling: Solar geoengineering could theoretically reduce global temperatures relatively quickly compared to mitigation efforts, such as reducing emissions, which take time to produce noticeable effects.
- Global Impact: The techniques would have a significant impact on the entire planet and could be utilized in the short term to mitigate global warming.
Challenges and Risks:
- Unintended Climate Effects: Altering solar radiation could disrupt weather patterns, such as monsoons, and impact regional climates, particularly in vulnerable areas.
- Moral Hazard: The availability of geoengineering could reduce the urgency of cutting greenhouse gas emissions, allowing continued reliance on fossil fuels.
Impermanence: If SRM is stopped abruptly, severe climate warming could occur as the planet rapidly absorbs the previously deflected sunlight.
“Geoengineering is not a substitute for cutting greenhouse gas emissions. If we’re going to engineer the climate, we should do it only as a last resort—and with great caution.”
— David Keith, Professor of Applied Physics at Harvard University and a leading researcher in solar geoengineering
- Current Status: Solar geoengineering is mainly theoretical, and many scientists view it as a controversial and risky approach. Research continues, but most experts agree that it should not be a substitute for reducing emissions and should only be considered a complementary, temporary option in extreme circumstances
The focus in the next 30 years should be on mitigating the carbon footprint of anthropogenic activities through technological improvements and green investments in innovative, low-carbon-intensity technologies to the greatest extent possible to stay below a 1.5-degree global temperature increase and find creative ways to sequester carbon.
