Scientists despair amid forecast of at least 2.5C temperature rise

Poll shows climate experts expect catastrophic heating

- Damian Carrington

Hundreds of the world's leading climate scientists expect global temperatures to rise to at least 2.5C (4.5F) above pre-industrial levels this century, blasting past internationally agreed targets and causing catastrophic consequences for humanity and the planet, an exclusive Guardian survey has revealed.

Almost 80% of the respondents, all from the authoritative Intergovernmental Panel on Climate Change (IPCC), foresee at least 2.5C of global heating, while almost half anticipate at least 3C. Only 6% think the internationally agreed 1.5C limit will be met.

Many of the scientists envisage a "semi-dystopian" future, with famines, conflicts and mass migration driven by heatwaves, wildfires, floods and storms of an intensity and frequency far beyond those that have already struck.

Numerous experts said they had been left feeling hopeless, infuriated and scared by the failure of governments to act despite the clear scientific evidence.

"I think we are headed for major societal disruption within the next five years," said Prof Gretta Pecl, of the University of Tasmania in Australia.

Authorities "will be overwhelmed by extreme event after extreme event, food production will be disrupted.

I could not feel greater despair over the future." But many say the climate fight must continue, however high global temperatures rise, because every fraction of a degree avoided will reduce human suffering.