SUNNY WITH A CHANCE OF PARTICLES
How We Can Dim the Sun to Survive Climate Change
All it takes is a fleet of planes spraying aerosols, diamond dust, or sea salt into the stratosphere.
Climate change is here, whether you believe in it or not.
Fighting climate change is a different matter entirely. It’s political. The U.N.’s Intergovernmental Panel on Climate Change (IPCC) has suggested carbon farming, or laying compost on undeveloped land to absorb carbon dioxide, as one of many viable plans that could help fight climate change.
But what if we could inject particles into the stratosphere to actually dim sunlight and reduce warming?
Solar radiation management, or SRM, is a serious option—one that scientists and policymakers are entertaining more and more. It works like this: A fleet of planes able to reach the stratosphere, originating from several equatorial regions around the planet, spray particles into the stratosphere regularly to reduce the amount of sunlight that reaches the troposphere (where we are).
These particles can range from sulfate aerosols, currently one of the most popular nominees because of how they dim sunlight after a volcanic eruption. But some scientists are even considering the idea of spraying diamond dust into the atmosphere. Researchers are also looking into using sea salt to brighten clouds, which would make them more reflective of sunlight.
One big obstacle to any of these methods is cost. To successfully deploy SRM, it would take a powerful country with a lot of reach, like the United States, or a group of countries to be in charge of managing these efforts.
Despite the cost factor, SRM comes at a crucial point for our planet. If we do not drastically increase efforts to combat climate change, the U.N. claims we’re on a path to see global temperatures rise by 3 degrees Celsius above pre-industrial levels. To put that in perspective, sea level is expected to rise over 7 feet per degree of warming. The sweltering heat alone would kill millions. A 3-degree Celsius increase would have calamitous effects across the globe.
Politicians have proposed reducing emissions, but scientists aren’t waiting around, instead looking at how to geoengineer the atmosphere to fight climate change. Besides SRM, carbon dioxide removal (CDR)—or literally sucking CO2 out of the air—has also gained traction.
But even that has sparked controversy. The U.S. and Saudi Arabia recently blocked a U.N. effort to study the benefits and risks of certain geoengineering concepts that could help fight climate change, like CDR and SRM. Reports claimed the countries did this to protect fossil fuel industry interests. The United States’ U.N. ambassador’s office did not respond to a request for comment.
That frustrates scientists.
“Why should [this administration] look into addressing a problem they claim does not exist,” Alan Robock, a professor of environmental science at Rutgers University, told The Daily Beast. “Global warming is a real problem, and we need to know what the risks of geoengineering would be if we are ever tempted to use it.”
On the surface, SRM might seem like a recipe for a dystopian future. Just imagine a scene in a movie where the scientists say they made the wrong calculations and they’ve accidentally unleashed a permanent winter.
However, preliminary research indicates the technique is relatively safe. A recent study that was published in Nature Climate Change found that SRM could reduce precipitation in some places, since less evaporation would occur. Using SRM to reduce climate change-related warming by only half would not cause precipitation to decrease to a concerning level.
“There have been a number of studies in the last 10 years, most of which… found if it’s successful and well implemented, it could reduce the amount of change due to global warming without, as far as we know, unexpected consequences,” Lynn Russell, a professor of atmospheric chemistry at the University of California, San Diego, told The Daily Beast.
Russell said one of the primary risks involved with SRM is that the atmosphere could respond to these particles in a negative way that we can’t yet predict. She said that years of research will be required before we’ll understand how the atmosphere might react to each kind of particle that might be used for SRM.
“What we don’t have a clear handle on is the feedback from the system,” Russell said. “We know that certain parts of the atmospheric system react with each other.” Russell added that altering the atmosphere in one area could create harmful effects in another area.
Beyond how the atmosphere might react to SRM, there are public health concerns. Scientists believe sulfate aerosol could not only damage the ozone layer, but also cause acid rain and further ocean acidification.
Additionally, Janos Pasztor, the executive director of the Carnegie Climate Geoengineering Governance Initiative, told The Daily Beast it’s not clear how dimming the sun might affect human health generally.
“It will be 1 to 1.5 percent less sunlight coming in on a regular basis, and that may not sound like a lot, but it could have an impact that we don’t understand at this point,” Pasztor said.
That said, reducing warming would have a lot of positive effects that outweigh turning the dimmer on the sun, slowing the melting of icecaps and preventing large regions of the planet from becoming unbearably hot, reducing the number of superstorms we’d have to endure.
“We know superstorms tend to be created because of extra heat in the ocean, so if you reduce that, then one would think… those risks would go down,” Pasztor said.
While geoengineering is promising, experts The Daily Beast spoke with emphasized not attempting it just yet until we completely understand side effects.
“There is not much money being spent on research in these areas, therefore not much is happening,” Pasztor said.
“What I would hope the world will avoid is a situation where we continue to emit greenhouse gases, don’t do much carbon dioxide removal—because it’s expensive and takes a long time to put in place—and suddenly in 10 to 20 years from now we find ourselves in a place where we’re on a dead end street and the only option is solar radiation modification.”