One cool solution

摘要

It is 2030, and a fleet of ten Gulfstream business jets have been converted to a new purpose: dispensing 250,000 tonnes of sulphates a year into the lower stratosphere. Here the chemicals form sunlight-reflecting droplets that cool the planet below. This artificial volcanic haze, costing about US$700 million a year, helps to mitigate the warming effect of greenhouse gases. This is the vision of David Keith, a physicist and self-described "oddball environmentalist". His company, Carbon Engineering, is currently pursuing a device that can suck carbon dioxide out of the air (see Nature 458, 1094-1097; 2009). Now, in A Case for Climate Engineering, Keith considers the partner concept of cooling the world by deflecting sunlight. Unlike journalist Eli Kintischs 2010 book Hack the Planet, this is not an exploration of all geoengineering schemes told through compelling stories and characters. Rather, it is a straightforward presentation of one controversial, planet-altering idea - along with an intriguing discussion of the philosophical roots of environmentalism.