Solar geoengineering is becoming a respectable idea

WHAT A DIFFERENCE a decade makes. That, roughly, is how often the Open Science Conference, run by the World Climate Research Programme (WCRP), comes along. At the previous get-together in 2011, says Jim Hurrell, a climate scientist and WCRP member, almost no one was talking about geoengineering. This is the idea of deliberately meddling with the Earth’s climate to try to make it cooler, and thus to offset the worst effects of another type of climatic meddling—namely greenhouse-gas-driven global warming.

At this year’s event, held in Rwanda, Dr Hurrell gave a keynote address on the subject. There were “dozens of papers and talks and posters”, he says. That reflects a broader shift in thinking. Although geoengineering has for many years been the subject of serious, albeit small-scale, scientific interest, it has been largely shunned by environmental NGOs and politicians. Now that is starting to change.