Global temperatures could rise by around 3.25 degrees Celsius (5.9 degrees Fahrenheit) by the end of the century under current policies, making Switzerland's most severe official climate scenario increasingly likely, according to research from Switzerland and Germany.
The study, conducted by researchers at ETH Zurich and Leipzig University, suggests that previous climate projections may have underestimated future warming, Swissinfo reported Tuesday.
"For any emission trajectory without immediate and drastic emission cuts, we expect warming to be 25% higher," said Gergana Gyuleva, a doctoral researcher at ETH Zurich and lead author of the study.
"What happens in a 3 degrees Celsius (5.4 degrees Fahrenheit) world isn't changed by our results. Our results only change how soon or how likely this 3 degrees Celsius world becomes," she said.
The findings have particular implications for Switzerland, which is warming faster than the global average. A world that is 3 degrees Celsius (5.4 degrees Fahrenheit) warmer than pre-industrial levels would translate into roughly 4.9 degrees Celsius (8.8 degrees Fahrenheit) of warming in Switzerland.
The country's hottest summer on record offered a glimpse of such conditions. Basel recorded 58 days above 30 degrees Celsius (86.5 degrees Fahrenheit), compared with 41 in 2003; Bern had 46 compared with 29, while Zurich had 38 compared with 27.
The scenarios published by MeteoSwiss and ETH Zurich last November projected about 30 days with temperatures above 30 degrees Celsius (86.5 degrees Fahrenheit) for the Zurich area in a typical summer under a 3 degrees Celsius (5.4 degrees Fahrenheit) warming scenario.
Researchers revised their projections by accounting for natural climate variability and satellite measurements of Earth's energy imbalance – the difference between incoming solar energy and heat radiated back into space.
The study also estimates that the remaining global carbon budget is around one-fifth smaller than previous models suggested.
"Our results point to the need for faster mitigation for a given temperature target," Gyuleva said.
Researchers stressed that the higher warming scenario is not inevitable, saying that severe emissions reductions could substantially limit future warming.
