"Many scenarios have been proposed to help us engineer our way out of potential climate disaster, and now a new study could point us towards the ones that are most effective. Tim Lenton of the University of East Anglia, UK, has put together the first comparative assessment of climate-altering proposals such pumping sulphur into the atmosphere to mimic the cooling effect of volcanic emissions, or fertilising the oceans with iron." - Steven Perez from Bookmarklet