Science Source

Concurrent 2018 Hot Extremes Across Northern Hemisphere Due to Human‐Induced Climate Change

States that the 2018 spring‐to‐summer season was characterized by several major heat and dry extremes
States that on daily average between May and July 2018 about 22% of the populated and agricultural areas north of 30° latitude experienced concurrent hot temperature extremes
States that events of this type were unprecedented prior to 2010, while similar conditions were experienced in the 2010 and 2012 boreal summers
Finds that Earth System Model simulations of present‐day climate, that is, at around +1 °C global warming, also display an increase of concurrent heat extremes
Shows, based on Earth System Model simulations, that it is virtually certain (using Intergovernmental Panel on Climate Change calibrated uncertainty language) that the 2018 north hemispheric concurrent heat events would not have occurred without human‐induced climate change
The results further reveal that the average high‐exposure area projected to experience concurrent warm and hot spells in the Northern Hemisphere increases by about 16% per additional +1 °C of global warming
Concludes that a strong reduction in fossil fuel emissions is paramount to reduce the risks of unprecedented global‐scale heat wave impacts