Billions of people could be living in regions where temperatures are hotter than their historical ranges by mid-century, creating a "new normal" that could force profound changes on nature and society, scientists said on Wednesday.
Temperatures in an average year would be hotter by 2047, give or take 14 years, than those in the warmest year from 1860-2005 if the greenhouse gas emissions continue to rise, with the tropics the first affected area, a new index indicated.
"The results shocked us. Regardless of the scenario, changes will be coming soon," lead author Camilo Mora of the University of Hawaii said. "Within my generation whatever climate we were used to will be a thing of the past."