We can brighten clouds to reflect heat and reduce global warming. But should we? “If the catastrophes we are trying to avoid are in the next 30 or 40 years, this may be the only thing that will reduce heat”

By Stuart Leavenworth
8 November 2017
WASHINGTON (McClatchy) – Ever-higher temperatures are melting the ice sheets faster than projected. Sea level is rising. International efforts to reduce greenhouse gases are taking longer than expected. It’s a nightmare scenario that could soon demand an emergency response. What to do?
One idea gaining traction is to seed marine clouds with salt water or other particles, increasing their potential to reflect solar rays, cooling the earth. Its part of nascent and controversial branch of science known as “sunlight reflection methods,” or SRM.“We think SRN could buy time for other (carbon-reduction) measures to be put in place,” said Philip J. Rasch, chief climate scientist for the Pacific Northwest National Laboratory in Richland, Washington.“If the worst case scenarios of global warming come to pass, these technologies could be used to help people, saving lives and economies from the worst effects of climate change,” added Joseph Majkut, director of climate policy at the Niskanen Center, a Washington D.C. think tank.Rasch and Majkut are two climate specialists who testified Wednesday before the House Committee on Science, Space and Technology, which held a subcommittee hearing on the potential for “geoengineering” — a catchall for proposals to directly cool the atmosphere or pull carbon emissions from it.While Republicans in the House often dismiss research that man-made emissions are a driving cause of global warming, some conservatives are interested in the potential of geoengineering techniques. They hope that technologies to cool the climate or remove carbon dioxide from the atmosphere will reduce pressure to impose more regulations on industry, particularly oil companies and other producers of fossil fuels.“As climate continues to change, geoengineering could be a tool to curb resulting impacts,” said Rep. Lamar Smith, a Texas Republican who chairs the House Committee on Science, Space and Technology. “Instead of forcing unworkable and costly government mandates on the American people, we should look to technology and innovation to lead the way to address climate change.”

At Wednesday’s hearing, all the specialists testifying said geoengineering techniques shouldn’t be substituted for efforts to reduce greenhouse gases and prepare for climate change impacts. This point was also hammered home in a letter Wednesday by 24 scientists and environmental advocates. It stated that “any consideration of a Federally funded and coordinated research program into geoengineering must be in the context of a strategic portfolio of responses to climate change.”Democrats on the committee mostly agreed.“It is absolutely critical to reduce carbon emissions and prepare for the changes that are coming,” said Rep. Jerry McNerney of California. But McNerney, a Ph.D. mathematician who urged Smith to hold Wednesday’s hearing, said Congress should also explore whether geoengineering could serve as a quickly needed insurance policy.“What tools are available? What are the technical feasibilities? What are the costs?” he said. “What are the risks of the different approaches to avoiding catastrophic change? That is where this hearing fits in.” [more]

We can brighten clouds to reflect heat and reduce global warming. But should we?