Pledge signed by experts from nine countries reflects concerns that offsets generated from forest-related projects may not have cut emissions

Carbon offsets used by corporations around the world to lower their reportable greenhouse gas emissions are “ineffectual” and “hindering the energy transition”, according to more than 60 leading climate change scientists.

A pledge signed by scientists from nine countries, including the UK, the US and Australia, said the “only path that can prevent further escalation of climate impacts” was “real zero” and not “net zero”.