For the first time, a study maps safe areas that can practically be used for underground carbon storage, and estimates that using them all would only cut warming by 0.7°C. The result is almost ten times lower than previous estimates of around 6°C, which considered the total global potential for geological storage, including in risky zones, where storing carbon could trigger earthquakes and contaminate drinking water supplies. The researchers say the study shows that geological storage is a scarce, finite resource, and warn that countries must use it in a highly targeted way.