Geoengineering -- intentionally altering Earth's climate to fight global warming -- may be risky science but it must be researched. The watchwords should be caution, openness, international cooperation, and humility.
Intentionally messing with the world’s climate sounds like something only a comic book villain would do.
But in March, at an unprecedented conference in northern California, a group of climate scientists and officials from several countries met to discuss how best to go about doing it.
“Geoengineering” is a blanket term used for a growing number of strategies for blunting the ill effects of global warming. Proponents argue it may be needed as a third option. Cutting emissions of greenhouse gases (mitigation) and preparing to live in a world with an altered climate (adaptation) are already much discussed.
Ironically, this emerging field has mostly reluctant proponents, earning geoengineering the title of “a bad idea whose time has come.”
Any attempts to manipulate Earth’s climate would entail many risks. Even those who favor research say many types of geoengineering should only be used in a worst-case scenario, if abrupt and severe climate change demanded a drastic response.
But geoengineering should join the public discussion, even if at first blush many of these ideas sound more like science fiction than solid science.
Some measures involve so-called solar radiation management – slightly dimming the amount of sunlight reaching Earth to create a cooling effect that would cancel out global warming from greenhouse gases. These ideas include shooting reflective particles into the upper atmosphere or creating “microbubbles” in ocean water that would act as giant mirrors to reflect more sunlight back into space.
“Artificial trees” could absorb CO2 just as real trees do and store it underground. Or perhaps real tree species would be genetically altered to be super efficient CO2 suckers.
One idea, seeding the world’s ocean with iron particles to promote the growth of CO2-gobbling algae, has become an early example of how unintended problems could arise. A new study shows that adding iron may favor growth of a type of algae that is toxic to humans.
Some argue that even researching geoengineering is unethical. They say that learning how to employ such measures will only ensure that they will be used someday – without a real understanding of the unintended consequences.