Climate change effects to be worse than previous estimates, new study shows

Across Europe, heat waves will become longer and more intense, while the Arctic will be entirely ice-free during summer in the last two decades of this century

The world may become hotter than previously expected by the end of the century, according to a major study by some 100 of the top researchers in the field in France.

In the worst-case scenario, average global temperatures may rise 6 degrees to 7 degrees Celsius (10.8 degrees to 12.6 degrees Fahrenheit) by 2100, according to the work released by France’s National Center for Scientific Research CNRS, the atomic energy commission CEA and weather office Meteo-France.

That reading is about 1 degree Celsius hotter than previous projections. It’s also well above the 2-degree threshold endorsed by the United Nations. Beyond that level,