By CLIVE HAMILTON
THE concentration of carbon dioxide in the earth’s atmosphere recently surpassed 400 parts per million for the first time in three million years. If you are not frightened by this fact, then you are ignoring or denying science.
Relentlessly rising greenhouse-gas emissions, and the fear that the earth might enter a climate emergency from which there would be no return, have prompted many climate scientists to conclude that we urgently need a Plan B: geoengineering.
Geoengineering — the deliberate, large-scale intervention in the climate system to counter global warming or offset some of its effects — may enable humanity to mobilize its technological power to seize control of the planet’s climate system, and regulate it in perpetuity.
But is it wise to try to play God with the climate? For all its allure, a geoengineered Plan B may lead us into an impossible morass.