Critical Climate Research Thwarted Amid Deadly Heatwaves: A Call for Continuation
The Earth's atmosphere consists of naturally occurring substances like pollen, dust, and sea salt from the ocean, as well as aerosols produced by human activities such as pollution. While greenhouse gas pollution traps heat and warms the planet, aerosols act like a sunshade, partially blocking solar rays. Aerosols cool the climate by reflecting sunlight directly and, more potently, by brightening clouds. This impact can be visibly observed from space as bright trails behind ships, expelling pollution aerosols as they sail across the oceans.
To date, this aerosol "umbrella" has mitigated around a third of the warming caused by greenhouse gas emissions. This may change due to new regulations that diminish ship pollution over the oceans and decreased air pollution in countries like China.
Dropping aerosol pollution levels comes with advantages for public health but also means the climate will heat up further. The extent of this heating is uncertain because the influence of aerosols on clouds is still one of the biggest unresolved issues in climate science.
Understanding aerosol effects on climate could help protect people from lethal heat waves. Approximately a billion people live in areas predicted to become explosively hot and humid, making it dangerous to be without air conditioning.
Although humans can withstand significant heat levels, there's a ceiling to what we can safely cope with. Lethally hot, humid conditions are becoming more common in various regions worldwide, including Bangladesh, the Persian Gulf, and certain areas of the U.S., such as Florida and Texas. In many of these locations, air conditioning is scarce, and even when available, a power outage or brownout could be fatal.
The Alameda program included research related to both general aerosol impacts and marine cloud brightening (MCB), an idea to brighten clouds with sea-salt spray instead of pollution aerosols. There are still essential areas of research that need attention to determine if MCB is feasible. This is why numerous scientific advisory reports have recommended research on quick climate interventions like MCB, including small-scale field trials to advance our understanding of how aerosols and clouds interact in real-world environments.
The suspended small sea salt studies in Alameda could have helped refine computer models projecting how reducing pollution aerosols will warm the climate and in which scenarios MCB might rescue lives by cooling it.
Some might question the purpose of concepts like MCB when we know the only long-term solution is to stop emitting greenhouse gases.
Firstly, extreme heat is already affecting us—hundreds died in Phoenix's record-breaking heatwave last summer—and this summer is expected to be even hotter. Reducing greenhouse gas emissions has urgent but gradual effects on climate, meaning that even if emissions reduction efforts are successful, more warming will occur over the next few decades.
What we urgently need is both an end to greenhouse gas emissions and protection from heat emergencies in the short term. These goals complement each other instead of contradicting, forming essential parts of climate planning.
Lessons from crises like Covid-19 teach us that when an emergency takes place, immaturity in scientific understanding results in confusion about effective measures and wasted efforts on ineffective treatments.
In deadly heat waves—especially in places with anticipated power grid failures and minimal air conditioning—local agencies might attempt MCB-like strategies as a desperate bid to reduce temperatures and save lives. Performing research on the science underlying MCB and similar interventions before these desperate attempts will better predict their effects—and significantly increase their chances of success.
Engaging in the small-scale sea salt research as part of a museum exhibit and educational program in Alameda could have been a transformative opportunity to educate the public about climate science and aerosols. Some Alameda residents objected to the research with fervor, not because they don't care about defending future generations from lethal heat, but out of apprehension of the unknown.
Many others supported the research, viewing science and information as beneficial for their community and the climate. At the same time, the City of Alameda carried out its environmental and health reviews and determined that the studies would not be harmful to people or animals near the site. Public education on aerosols and MCB is desperately needed—and would have been a significant part of the Alameda program had it continued.
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Research like the small-scale sea salt studies proposed in Alameda will not affect the clouds or climate, but it will enhance our understanding of whether it's feasible to cool down areas experiencing deadly heatwaves. This research might demonstrate that MCB isn't practical—which would be helpful to know and prevent unnecessary resources and time from being spent during a climate crisis. On the other hand, it could reveal how to use MCB to save lives during a manmade disaster.
Given the stakes, shouldn't we study every possible solution—and in the most open ways possible?
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In the ongoing debate about climate change, different opinions on the use of climate interventions like marine cloud brightening (MCB) emerge. Some people believe that focusing on reducing greenhouse gas emissions is the only long-term solution, while others argue that quick interventions like MCB could help mitigate heat emergencies in the short term.
Understanding various opinions and scientific findings is crucial in developing effective climate policies. Research results can inform decision-makers and the public about the potential benefits and drawbacks of different strategies, allowing for informed and collaborative climate planning.
