Earth’s climate will warm 15 per cent more than we thought

Climate models have always offered a range of possible temperature rises, but it turns out the ones that best fit what’s happened so far all predict even greater warming

CHILDREN born now could live to witness the planet warming more than 4°C, even if we cut greenhouse emissions by a fair amount. That’s one of the terrifying implications of a study that adds to the growing evidence that the “official” projections underestimate future warming.

“Basically, it shows between 10 and 20 per cent more warming than previously reported,” says Patrick Brown of Stanford University in California.

The biggest problem for global warming forecasts is that we don’t know how much more carbon dioxide and other climate-altering stuff will be released. Even if we assume greenhouse gases reach a specific level, climate models still produce a wide range of results.

To narrow that range, Brown and Ken Caldeira, also at Stanford, tried to pick the climate models whose projections to date best match real-world data.

They chose several measures: for instance, how much heat