Chinese scientists analyzing health data from more than 200 countries and territories discovered people are more likely to suffer fatal or disabling strokes when the climate changes. While the recent study in the journal Neurology does not directly attribute the strokes to human-caused climate change, it notes an increase in the number of strokes clinically diagnosed as at least partially caused by "sub-optimal temperatures." The total number of patients whose strokes fall into that category — 521,031 stroke deaths in 2019 alone — is higher than one would anticipate even when adjusting for other variables that could explain it (such as obesity, lifestyle and income).
There is important context for that figure. "Sub-optimal temperatures" refers to temperatures both warmer and colder than the range associated with lower death rates. Among the more than half-million 2019 stroke deaths in which sub-optimal temperatures were a factor, 474,002 were on the lower rather than higher end of the spectrum. At the same time, the number of strokes linked to heat is increasing rapidly, with the victims disproportionately coming from low income regions such as Africa and Central Asia.
