Climate change will have much more far reaching effects on health than predicted, with the greatest impact on the world’s poorest people, warns a year long investigation published this week.

“Climate change is the biggest global health threat of the 21st century,” warns Antony Costello, professor of international child health at the Institute for Global Health, University College London, and lead author of the report. “Climate change is a health issue affecting billions of people, not just an environmental issue about polar bears and deforestation.”

The report summarises the findings from a year long commission held jointly between the Lancet and the University …