Giving Compass' Take:

• Rachel Kaufman reports on the possible risks and rewards of geoengineering Earth’s climate according to climate scientists, who are divided on the subject.

• How can funders help to advance climate research? Which risks are worth taking? 

• Learn more about geoengineering climate solutions.

A growing body of evidence highlights the fact that the climate is changing, and human activity is the primary cause. The recent National Climate Assessment, compiled by more than 300 scientists and based on decades worth of research, found that the U.S. has already warmed nearly 2 degrees Fahrenheit (1.1 degrees Celsius) since 1900, snowpack has dwindled away, and sixteen of the warmest seventeen years on record have occurred since the year 2000.

While many scientists believe that geoengineering the Earth may someday be necessary to preserve life as we know it, the public, so far, isn't buying it. As a result, the preliminary research to figure out if geoengineering projects would even work is proceeding with extreme caution.

Researchers have proposed brightening clouds, making sea spray more reflective, or even launching a giant mirror into space to reflect extra sunlight. The most promising and affordable of these methods is stratospheric aerosol injection, which involves spewing tiny particles into the upper atmosphere. Those particles would reflect sunlight away from the Earth, effectively dimming the sun and, in theory, cooling the planet.

Many studies using computer models have shown that this method would, in theory, work. The latest such study, published today in Nature Climate Change, used a sophisticated model that simulates extreme rainfall and hurricanes, and found that reflecting sunlight with aerosols could uniformly cool the globe with minimal additional effects.

But when it comes to geoengineering, the research falls into a catch-22 of being too risky to rush, and some scientists say, too important to delay.

When asked if scientists should conduct preliminary experiments to lower the uncertainties and risks of geoengineering, Parkinson was silent for a long time. She finally said, “If I were voting on it right now, I would vote no.” In Parkinson’s view, we need to focus on technologies that remove carbon from the atmosphere or simply use less of it in the first place.

Geoengineering research could also divert funds from known carbon-reduction strategies like solar and wind energy. Even the knowledge that we could cool the planet with aerosols, some argue, would remove the incentive to decarbonize. But most geoengineering proponents agree that even with something like large-scale stratospheric aerosol injection, we'd still need to reduce carbon in the atmosphere. If we don’t, we'll have to keep pumping more and more aerosols up there—literally forever. And dimming the sun may help fight climate change, but it doesn't alter any of carbon dioxide's other nasty effects, like ocean acidification, which is killing coral, shellfish and plankton around the globe.

Read the full article about geoengineering earth’s climate by Rachel Kaufman at Smithsonian.