Californians are poised to become sicker in a future marked by climate-fueled warming, but they may also be less likely to die from temperature-related events as extreme cold days become rarer, a new study has found.
Emergency room visits in California increased in a linear fashion as daily temperatures escalated over the course of a recent decade, from 2006 to 2017, according to the study, published on Wednesday in Science Advances. But neither hospital admissions or related-death exhibited the same unbending climb.
Although extreme heat and extreme cold alike cause more people to die, illness rates tend to increase as the weather becomes hotter, and they tend to be lower in colder conditions, the study authors explained.
In other words: Emergency visits are still likely to surge as the planet warms, but temperature-related deaths as a whole may decline thanks to the ongoing disappearance of extreme cold days.
The researchers — led by Carlos Gould at the University of California San Diego — analyzed 123 million zip code-level emergency department visits, 45 million such hospital admissions and 2.9 million county-level death records between 2006 and 2017. They also compiled daily temperature records from 1,500 zip codes in 56 California counties for the same period.
Over time, they observed that the zip codes experienced an increase in emergency room visits: from an average of 1,936 per 100,000 people every month to 2,531 in 2017.
During the same window, both hospitalization rates and deaths showed a U-curve for temperature — exhibiting unsurprising increases during extreme cold and hot periods.
The scientists calculated an increase in emergency department visits California due to changes in temperatures by 2050 — an additional 0.46 percent, or 1.5 million excess visits, in comparison to today.
At that point, related hospitalizations and deaths will both likely decline, by 0.18 percent and 0.43 percent, respectively, or 244,000 fewer hospitalizations and 53,500 fewer deaths, according to the study.
By 2100, the researchers projected a 0.76 percent increase in emergency department visits, a 0.38 percent decline in hospital admissions and a 0.77 plunge in deaths due to temperature changes.
As far as economics are concerned, the scientists calculated that by 2050, emergency room visits would cost California an additional $52 million, while temperature-related death costs would decrease by $30 billion and hospitalization costs by $53 million.
Going forward, the researchers called for further analysis into the morbidity and mortality — illness and death — impacts of temperature variation within populations, noting that specific effects may differ considerably among age groups.
“A very broad range of morbidity outcomes will likely be affected by a warming climate and that future increases in heat extremes will increase both morbidity and mortality,” the authors stated.
And with a much warmer future likely ahead, the researchers questioned just how long the decreases in death related to cold could truly outweigh the increases related to excessive warmth.
“Our results suggest that beneficial impact of declining cold extremes for mortality — an expected substantial benefit of climate change in much of the world — will be offset, at least partially, by increases in morbidity at those temperatures,” they added.
