We urgently need to cut emissions – the good news is we can do it quickly and relatively cheaply | Frank Jotzo

The IPCC finds that emissions could be halved globally by 2030 at affordable costs if action is taken right across the board

Enormous opportunities to cut emissions deeply are there, the time to act is now, and it can be done at affordable cost.

That would be the shortest possible summary of the thousands of pages of careful assessment in the world's definitive stocktake of how to limit future climate change.

Frank Jotzo is a professor at the Australian National University. He is a lead author of the sixth assessment report of Working Group III of the IPCC, and co-author of its summary for policymakers.