By Jonathan Marshall
Scientists in England are preparing to launch a helium balloon the size of Wembly Stadium—the second largest soccer arena in Europe—to loft a hose high into the sky. Their goal: to test whether pumping water mixed with fine particles into the upper atmosphere can reflect enough sunlight to cool an overheating planet.
The past year’s onslaught of heat waves, droughts, hurricanes, floods and wildfires, which almost certainly was aggravated by climate change, lends urgency to their research. But the best evidence to date suggests there’s no cheap or easy alternative to doing the hard work of curbing greenhouse gas emissions, according to a recent report by the Government Accountability Office (GAO).
Disappointed with the slow pace of world collaboration to that end, some scientists and big thinkers have toyed with other global interventions that might keep the Earth cool. Commonly termed “geoengineering,” they include proposals to lace the upper atmosphere with reflective aerosols, seed white clouds to screen the planet from the sun, and fertilize the ocean’s plankton to consume more carbon dioxide.
The GAO reviewed a mass of studies and consulted a wide variety of scientific experts with the assistance of the National Academy of Sciences. Its conclusion: the proposed technologies are “currently immature, many with potentially negative consequences.”
For example, models predict that shooting the stratosphere full of sulfur aerosols—one of the most popular proposals—could drastically reduce summer rainfall in India and northern China.
Would either country ever agree to such an intervention—and if another country tried it unilaterally, might they view it as an act of war?
And that’s only the beginning of the problems. Mass release of sulfur aerosols would increase in acid rain and accelerate the poisonous acidification of the oceans. If greenhouse gas emissions were not curbed, runaway warming could result if the aerosol program ever broke down.
George Monbiot, an outspoken columnist for the London Guardian, calls geoengineering “atmospheric liposuction, a retrospective fix for planetary over-indulgence.”
A landmark study by the Royal Society two years ago advocated further research into geoengineering but warned of “major uncertainties regarding its effectiveness, costs, and environmental impacts.”
“The safest and most predictable method of moderating climate change is to take early and effective action to reduce emissions of greenhouse gases,” it concluded. “No geoengineering method can provide an easy or readily acceptable alternative solution to the problem of climate change.”
It appears that scientists on both sides of the oceans agree. Too bad it’s so much harder to get consensus among governments on policies to tackle carbon emissions.