Ask NASA Climate | April 14, 2014, 14:15 PDT

Nuking the sky

Unintended consequences

Amber Jenkins
Erik Conway

The planet is warming and our climate changing. As political leaders around the world fail to reach agreement on how to curb the greenhouse-gas emissions that are the underlying problem, others are touting a more radical way to combat climate change: "geoengineering." The idea behind geoengineering is to deliberately tinker with the climate system to counteract man-made climate change. Schemes suggested include making clouds and crops brighter so that they reflect more sunlight back out into space, using high-altitude balloons to inject aerosols into the stratosphere and cool the Earth, or sucking carbon dioxide out of the air so that it can't trap heat and contribute to global warming. In the absence of a planet B, hacking the planet is a possible plan B. (See our "Just 5 questions" article for more info.)

Project Argus
Project Argus, launched in 1958, was one of the first attempts at planetary engineering.

But the idea isn’t actually new. As James Fleming, a historian of science at Colby College, argues in his history of geoengineering, “Fixing the Sky,” one of the first attempts to engineer the planet was Project Argus in 1958. A top-secret military endeavor, Project Argus detonated atomic bombs in the upper atmosphere – about 500 kilometers (roughly 300 miles) up. The goal was to demonstrate that enemy radio and radar communications could be disrupted from half a world away, or enemy intercontinential ballistic missiles could be destroyed. In the process, the experiment also created a new radiation belt around the Earth that lasted for several years, disrupting the natural magnetosphere.

James Van Allen, discoverer of the Van Allen radiation belts, initially waxed enthusiastic at Argus’ accomplishment: “The U.S. tests, already carried out successfully, undoubtedly constitute the greatest geophysical experiment ever conducted by man.” Argus was followed by other U.S. and Soviet high-altitude tests, lasting until 1962. But radio astronomers were not so happy, arguing: “No government has the right to change the environment in any significant way without prior international study and agreement.” Argus had interfered with their science.

Van Allen later regretted his participation in these experiments, and above-ground nuclear weapons testing was finally banned in 1963, ending the career of this kind of geoengineering.

The history of these interventions and the ensuing protests serve as a cautionary tale for today’s geoengineers and, indeed, the organizations that will be tasked with regulating any future geoengineering. While some are keen to jump in with a quick and possibly profitable fix to climate change, others see a field fraught with technical, moral and political problems. As Fleming writes: “Geoengineering is in fact untested and dangerous. We don’t understand it, we can’t test it on smaller than planetary scales, and we don’t have the political capital, wisdom, or will to govern it. Planetary tinkering is not “cheap”, as some economists claim, since the side effects are unknown … Most poignantly, by turning the blue sky milky white or the blue oceans soupy green, by attenuating sunlight – and with it starlight, and by putting bureaucrats and technocrats in charge of a global thermostat, geoengineering will alter fundamental human relationships to nature.”

Related content:

Just 5 questions: Hacking the planet
Building a better soybean for a hot, dry, hungry world