Shoot up and cool down

New study examines a way to fight global warming by injecting sulfur into the atmosphere

Injecting sulfur into the atmosphere to slow down global warming is worthy of serious consideration, according to Nobel laureate Paul Crutzen from the Max Planck Institute for Chemistry in Germany and the Scripps Institution of Oceanography, University of California at San Diego. His thought-provoking paper1 is published in the August issue of the Springer journal Climatic Change, devoted this month to the controversial field of geoengineering.

Fossil fuel burning releases carbon dioxide into the atmosphere, which contributes significantly to global warming. Burning of fossil fuel also releases sulfur into the earth’s atmosphere, in the form of sulfate particles. Ironically, these sulfate particles help to cool down the planet by reflecting solar radiation back into space. Crutzen’s proposed planet-saving scheme, which artificially injects sulfur into the earth’s stratosphere (the second atmospheric layer closest to earth) to offset greenhouse gas warming, is based on this phenomenon.