Climate change is one of the most pressing and urgent matters facing humanity. Current solutions are making an impact but not necessarily at a large enough scale to change the underlying trend. Further, the major push is to increase electrification, and this certainly reduces emissions, but there are some drawbacks such as the need to source metals and periods when fossil fuels have to be used.
Another idea is solar geoengineering which is essentially a plan to reduce the amount of sunlight that is reaching the Earth to slow or stop global warming. The White House is coordinating a 5-year plan to research the process which includes ideas like spraying aerosols to reflect sunlight back into space.
Part of the research will involve studying the risks and benefits of such actions to help prevent a catastrophic increase in the Earth's temperature. In recent years, the concept of sunlight reflection has gained steam with support from the Environmental Defense Fund, NRDC, and the United Nations.
These efforts are expected to be complementary to emissions reduction but could possibly offer an alternative path. However, in the same way, that carbon emissions are disturbing the ecosystem's equilibrium, it's also possible that these interventions could have devastating adverse effects.
It's estimated that it would cost about $10 billion per year to put particles in the air above the ocean that would reflect back sunlight. In total, this would lower temperatures by 1 degree Celsius. This is much more cost-effective than current remedies.
In 1991, Mount Pinatubo had a volcanic eruption which resulted in the release of tons of sulfur dioxide. Scientists estimate that it reduced global temperatures by about 1 degree Fahrenheit. Similarly, in factories that have sulfur dioxide as a byproduct, it's also provided some insulation against the sun.
Other ideas include spraying sea salt crystals in the air around the ocean and cirrus cloud thinning. This basically involves reducing the density of certain clouds which would allow more heat to rise.
Overall, this effort seems an interesting path to research given the potential benefits at a very reasonable cost. It's also possible that countries, dealing with extreme weather, could pursue such policies on their own initiative, which also raises questions of ethics and sovereignty that should be investigated now before it's too late.