A new statement from the National Research Council urged that short-term climate interventions are not a viable alternative for reducing carbon emissions.
The council said that, while costly and underdeveloped, strategies to remove carbon dioxide from the atmosphere could be useful in the future. On the other hand, albedo-modification technologies, which increase the ability of the Earth and its clouds to reflect sunlight, could come with consequences and should not be deployed at this time.
Until now, both carbon dioxide removal and albedo-modification techniques have been classified under the blanket term "geoengineering." These new statements highlight the fact that the two strategies vary greatly in "environmental risks, socio-economic impacts, cost, and research needs." Carbon dioxide removal works to combat what is believed to be the root cause of climate change, while albedo-modification techniques only mask the phenomenon's effects. The council believes these two strategies would be more accurately described as "climate interventions" because they are actions to curb the negative impacts of climate change rather than "engineered" strategies to control the climate.
"That scientists are even considering technological interventions should be a wake-up call that we need to do more now to reduce emissions, which is the most effective, least risky way to combat climate change," said committee chair Marcia McNutt, editor-in-chief of Science and former director of the U.S. Geological Survey. "But the longer we wait, the more likely it will become that we will need to deploy some forms of carbon dioxide removal to avoid the worst impacts of climate change."
The researchers urged that if humans so decide to take climate-controlling action, there should be a much greater body of scientific evidence backing up the decision than what is currently available.
"If the world cannot slow emissions or the effects of climate change are more extreme or occur sooner than expected, there may be demands to pursue additional climate-intervention technologies about which scientists need a better understanding," said National Academy of Sciences President Ralph J. Cicerone. "Although riskier ideas to lessen the amount of energy absorbed from the sun should not be considered for deployment, they should be studied so that we can provide answers if someday these ideas begin to be considered in attempts to avert catastrophe. These reports should guide federal agencies in supporting research on climate-intervention technologies, while keeping separate any decision-making about their implementation."