Reacción a "Reaction to study claiming that the frequency of heatwaves will increase this century "

Contrary to many studies on future estimates of climate variables (such as temperature and precipitation), in which alternative scenarios of greenhouse gas emissions are selected from the outset and no assumptions are made about the greater or lesser likelihood of different scenarios, this paper presents as a starting point a probabilistic scenario of CO2 emissions (as the main greenhouse gas) for mid (2050) and end of century (2100).  

These probabilistic projections of CO2 emissions are based on data on population growth, GDP and carbon intensity by country. Using these projections, the authors present a statistical projection of a heat stress index that takes into account both temperature and humidity.  

The results of these projections show large areas in tropical regions with a number of days where the index values are dangerous or extremely dangerous to human health. The maps also show important areas in mid-latitudes, including the Iberian Peninsula, affected by a significant number of days with dangerous heat stress.  

The authors conclude that, to reverse these projections, CO2 emissions would need to be drastically and rapidly reduced in line with the Paris Agreement. This work - with a novel approach - stresses the importance of controlling greenhouse gas emissions if we do not want to have significant parts of the Earth subjected to heat stress conditions that endanger the health and lives of the inhabitants of these regions, with the associated consequences of social instability, mass migrations, etc.