The Confounding Case of the Climate Crisis by Owen R Liu

Other causes, including cancer, have been shown to have a substantially weaker association with ambient temperatures. Apart from all-cause or non-external causes of mortality, cardiovascular and respiratory deaths have been found to be associated with both heat and cold exposure, with V-, U-, or J-shaped temperature–mortality relationships observed, with the optimum temperature corresponding to the lowest point in the curve. Findings suggest that both high and low temperatures increase mortality, with heat-related mortality occurring during the first few days after temperature increase, whereas the effects of coldness are prolonged for several weeks.

A substantial number of existing studies examined associations between meteorological variables and health-related outcomes using daily time series study design. As a result of the increasing concern regarding the public health effects of meteorological conditions, such as extreme temperatures, associations between extreme temperatures and mortality/morbidity have been identified repeatedly and consistently in studies from around the world. Whereas climate change has become a widely recognized global challenge in this century, its human health impacts have wide implications.

The findings and methodology of this study may help to further understanding and investigation of social and structural determinants of health disparities, particularly place-based built environment across class-based small geographic units in a city, taking into account the intersection of multiple factors from individual to population levels. We also found that the spatial variation of mortality within this city could be explained by the geographic distribution of green space and socioeconomic factors rather than local temperature or air pollution. We found that a 10% increase in green space density was associated with an estimated 4.80% decrease in non-accidental mortality risk and a 5.75% decrease in cardiovascular disease mortality risk in Hong Kong, whereas variation in local annual temperature did not significantly contribute to mortality. The effects of local temperature on non-accidental and cause-specific mortality were analyzed using Bayesian spatial models at a small-area level, adjusting for potential confounders, i.e., area-level air pollutants, socioeconomic status, and green space, as well as spatial dependency. Whereas previous studies have assessed the overall health impact of temperature in Hong Kong, the aim of this study was to investigate whether the health impact is modified by local temperature of small geographic units, which may be related to the diverse socioeconomic characteristics of these units.

The Confounding Case of the Climate Crisis by Owen R Liu