A study in BMC Medicine based on 134,403 adults in Fujian, Hubei, and Yunnan links higher carbon dioxide exposure and more frequent heatwaves to increased odds of diabetes. Each CO2 increment was tied to an odds ratio of 1.14, while more heatwave days carried an odds ratio of 1.48. The researchers used satellite-derived CO2 data and a thermal comfort index rather than city-wide averages, and adjusted for age, diet, smoking, and other pollutants. The associations were stronger among less educated and rural participants, and BMI explained part of the CO2 link. The authors note the design is cross-sectional, so it shows correlation, not proof of causation. Still, the results add a health argument for cutting emissions and expanding cooling access in vulnerable areas.
