Global warming is accelerating faster than currently understood and will lead to a key temperature threshold being crossed as early as this decade, according to research led by James Hansen, the American scientist who first alerted the world to the greenhouse effect. The Earth's climate is more sensitive to human-induced changes than scientists previously realized, meaning a "dangerous" burst of warming will be triggered, leaving the world 1.5°C warmer than pre-industrial average by the 2020s and 2C warmer by 2050, a book published on Thursday predicts. This alarming acceleration in global warming, which would see the world exceed the internationally agreed 1.5C threshold set out in the Paris climate agreement much sooner than expected, threatens a world “less tolerable for humanity, with greater climate extremes,” according to a study led by Hansen, a former NASA scientist who issued a seminal warning about climate change to the US Congress as early as the 1980s. (Oliver Milman, the Guardian)