Switzerland, the U.K. and Norway will experience the largest relative surge in cooling needs if the increase in global mean temperature passes 1.5 degree C and rises to 2 degree C above pre-industrial levels, according to a modelling study published in Nature Sustainability. The findings also suggest that countries in sub-Saharan Africa will have the greatest increase in cooling requirements.
The Paris Agreement aims to limit the rise in the global mean temperature to 1.5 degree C. Rising temperatures are already driving cooling demand, and it has been estimated that by 2050 the energy required by cooling could be the equivalent of the combined electricity capacity of the U.S., the European Union and Japan in 2016, as reported by the International Energy Agency (IEA).
Based on a global atmospheric General Circulation Model and historical climate data for 2006-2016, the researchers have estimated the annual changes in cooling degree days (CDDs) if the 1.5 degree C limit is overshot and warming increases to 2 degree C. The cooling degree days compare the mean outdoor temperature of a region to a standard baseline temperature (in this case 18 degree C), to determine temperature exposure and cooling requirements.
The results show that regions surrounding the Equator, particularly the sub-Saharan countries (Central African Republic, Burkina Faso, Mali, South Sudan and Nigeria) would have the greatest increase in cooling demand.
According to the study, the results of relative changes in CDDs show that countries in the Global North (Switzerland, the U.K., Scandinavian countries, Austria, Canada, Denmark, and Belgium), which traditionally experienced cooler temperatures, will now experience largest relative increases in the number of days that require cooling. “Eight of ten are European nations, which are traditionally unprepared for high temperatures and will require large-scale adaptation to heat resilience,” they write.
The authors note that there are still uncertainties regarding when these temperature increases will occur across different countries and the role that changes in other parameters, such as humidity, will play. However, they conclude that their results indicate that even small changes in temperatures will affect heat exposure and cooling demand, driving the need for adaptations.
“Immediate and unprecedented adaptation interventions are required worldwide to be prepared for a hotter world,” they write.
