By Carl Bildt
STOCKHOLM – Heat waves and extreme-weather events across the Northern Hemisphere this summer have brought climate change back to the forefront of public debate. Early analyses strongly suggest that natural disasters such as Hurricane Florence – which barreled into the US East Coast this month – have been exacerbated by rising global temperatures. Though US President Donald Trump has reneged on the 2015 Paris climate agreement, the rest of the world is becoming increasingly convinced of the need to limit greenhouse-gas (GHG) emissions.
Last month, a group of climate scientists published a report in the US Proceedings of the National Academy of Sciences warning that the planet could be on a path to becoming a “hothouse” that may not be habitable for humans. The Earth has already registered the highest temperatures since the last Ice Age. But, as the report notes, what we are experiencing today will be nothing compared to what is in store if average global temperatures surpass 2° Celsius above pre-industrial levels.
At that point, the authors write, “[global] warming could activate important tipping elements, raising the temperature further to activate other tipping elements in a domino-like cascade that could take the Earth System to even higher temperatures.” The scientific debate about climactic tipping points and nightmare scenarios is ongoing. But no one can say for certain that the risks outlined in the “Hothouse Earth” report are not real.