The burden of heat-related mortality attributable to recent human-induced climate change

Climate change affects human health; however, there have been no large-scale, systematic efforts to quantify the heat-related human health impacts that have already occurred due to climate change. Here, we use empirical data from 732 locations in 43 countries to estimate the mortality burdens associated with the additional heat exposure that has resulted from recent human-induced warming, during the period 1991-2018. Across all study countries, we find that 37.0% (range 20.5-76.3%) of warm-season heat-related deaths can be attributed to anthropogenic climate change and that increased mortality is evident on every continent. Burdens varied geographically but were of the order of dozens to hundreds of deaths per year in many locations. Our findings support the urgent need for more ambitious mitigation and adaptation strategies to minimize the public health impacts of climate change.

The effects of hot nights on mortality in Barcelona, Spain

Heat-related effects on mortality have been widely analyzed using maximum and minimum temperatures as exposure variables. Nevertheless, the main focus is usually on the former with the minimum temperature being limited in use as far as human health effects are concerned. Therefore, new thermal indices were used in this research to describe the duration of night hours with air temperatures higher than the 95% percentile of the minimum temperature (hot night hours) and intensity as the summation of these air temperatures in degrees (hot night degrees). An exposure-response relationship between mortality due to natural, respiratory, and cardiovascular causes and summer night temperatures was assessed using data from the Barcelona region between 2003 and 2013. The non-linear relationship between the exposure and response variables was modeled using a distributed lag non-linear model. The estimated associations for both exposure variables and mortality shows a relationship with high and medium values that persist significantly up to a lag of 1-2 days. In mortality due to natural causes, an increase of 1.1% per 10% (CI95% 0.6-1.5) for hot night hours and 5.8% per each 10° (CI95% 3.5-8.2%) for hot night degrees is observed. The effects of hot night hours reach their maximum with 100% and lead to an increase by 9.2% (CI95% 5.3-13.1%). The hourly description of night heat effects reduced to a single indicator in duration and intensity is a new approach and shows a different perspective and significant heat-related effects on human health.

Winter circulation weather types and hospital admissions for respiratory diseases in Galicia, Spain

The link between various pathologies and atmospheric conditions has been a constant topic of study over recent decades in many places across the world; knowing more about it enables us to pre-empt the worsening of certain diseases, thereby optimizing medical resources. This study looked specifically at the connections in winter between respiratory diseases and types of atmospheric weather conditions (Circulation Weather Types, CWT) in Galicia, a region in the north-western corner of the Iberian Peninsula. To do this, the study used hospital admission data associated with these pathologies as well as an automatic classification of weather types. The main result obtained was that weather types giving rise to an increase in admissions due to these diseases are those associated with cold, dry weather, such as those in the east and south-east, or anticyclonic types. A second peak was associated with humid, hotter weather, generally linked to south-west weather types. In the future, this result may help to forecast the increase in respiratory pathologies in the region some days in advance.