Global heating is accelerating, warns scientist who sounded climate alarm in the 80s

Study delivers dire warning although rate of increase is debated by some scientists amid a record-breaking year of heat

Global heating is accelerating faster than is currently understood and will result in a key temperature threshold being breached as soon as this decade, according to research led by James Hansen, the US scientist who first alerted the world to the greenhouse effect.

The Earth's climate is more sensitive to human-caused changes than scientists have realized until now, meaning that a dangerous" burst of heating will be unleashed that will push the world to be 1.5C hotter than it was, on average, in pre-industrial times within the 2020s and 2C hotter by 2050, the paper published on Thursday predicts.