Julien Emile-Geay, USC Dornsife College of Letters, Arts and Sciences
Thanks to humans, the concentration of planet-warming carbon dioxide in the atmosphere is now 50% higher than before the industrial era. These gases are raising Earth’s temperature.
Blocking the sun by injecting tiny particles in the atmosphere – called solar geoengineering – can lower the Earth’s temperature but has some real costs. Economists run the numbers.