What is Solar Geoengineering?

Posted on Apr 8, 2019 in Sustainable Living & Sustainable Lifestyle by Matthew Speer 0 Comments

Solar geoengineering involves emerging technologies that show promise at helping offset the effects of climate change when used along with carbon dioxide reduction. Chief among these is solar radiation management, which involves reflecting the sun’s rays from the planet to reduce global warming.

These projects are still in their earliest stages. However, they already show great promise. Harvard University’s Solar Geoengineering Research Program is among many high-profile programs that are looking into solar radiation management.

Geoengineering: A Fast Response

Research into solar geoengineering has gained momentum as the harms of climate change continue to become more ominous. The United Nations issued a warning in 2018 that the next decade is critical in the fight against climate change to avoid issues such as extreme heat, drought, floods and poverty around the world.

Solar geoengineering provides a possible solution. Using engineering projects that manipulate the Earth’s environment could provide a fast, temporary relief from climate change as the world works to reduce carbon emissions. As noted by Harvard and others, however, solar geoengineering is meant to work in conjunction with emissions reduction, not a replacement for it.

The amount of carbon being put into the air right now will last for thousands of years, perhaps even longer. And it will take decades – perhaps as long as a century – for humanity to switch its energy system from fossil fuels to other, more sustainable and less harmful energy sources. Geoengineering may help bridge that time gap.

Solar Radiation Management

The most well-known of solar geoengineering projects involves the idea of solar radiation management. To put it simply, why not deflect some of the sun’s rays from the Earth to lower the chances of global warming?

Some of the strategies under consideration include:

Marine cloud brightening. This involves brightening marine clouds so that they reflect more sunlight back into space
Cirrus cloud thinning. By thinning out these clouds, the planet can emit more longwave radiation into space
Sun shields. This space-based solution would involve reflecting small portions of sunlight from Earth by putting sun shields into orbit around the planet.
Stratospheric aerosol scattering. This involves scattering small, reflective particles into the stratosphere (including sulfate aerosols or calcium carbonate) where they would reflect a fraction of sunlight back into space.

More research is needed to determine the best methods. But if such projects work, solar geoengineering could prove “a powerful supplement” to cutting emissions, according to David Keith, a professor of applied physics at Harvard.

While relatively new ideas, expect solar geoengineering and solar radiation management to become bigger topics among governments and leaders around the world. With humanity searching for answers to climate change, every idea deserves to be heard.