Cooling demand in San Francisco schools has surged
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Classrooms in the Bay Area now need more cooling during back-to-school season compared to past decades, a new analysis finds.
Why it matters: A comfortable and healthy environment in schools is key to kids' educational success, but that's getting harder amid a warming climate.
- Many schools are already making adjustments. Some in the Austin, Texas, area, for example, have shifted recess earlier and are limiting kids' outside time.
Driving the news: A Climate Central report finds that cooling demand between late July and early September increased in 95% of nearly 250 U.S. locations analyzed between 1970 and 2023.
- The nonprofit climate research group's analysis is based on a metric called "cooling degree days" (CDD), which measures the difference between a location's daily average outdoor temperature and 65° — "considered the ideal indoor temperature," per the report.
- "For example, a day with an average temperature of 90°F has 25 CDD (90°- 65°)."
What they did: To get annual demand, CDD was added together for every day in the seven-week period when students typically return to school.
Zoom in: Among the locations analyzed, San Francisco (+240%) saw the third-biggest percentage increase in back-to-school CDD between 1970 and 2023.
- On average, the largest increases in back-to-school CDD were in the West (+86%).
- Reno, Nevada (+320%) clinched the top spot, followed by Eureka, California (+300%).
Between the lines: Back-to-school cooling demand was around 34% higher over the last decade largely due to human-caused climate change, Climate Central estimates.
- That's based on the group's Climate Shift Index, which seeks to measure how climate change has affected daily temperatures.
Threat level: Many schools in rapidly warming locations also start school in mid- to late August, when heat waves can strike.
The big picture: The California Department of Public Health issued guidance last year for schools navigating extreme heat, warning that rates of exertional heat illness among high school athletes are higher in American football than all other sports combined.
- A new indoor heat standard that took effect in July also requires California school districts to keep classrooms cool.
Yes, but: California state agencies don't keep track of schools and classrooms that lack air conditioning, environmental policy analysts say.
What's next: Like other buildings, schools must adapt to a changing climate — and that can mean costly upgrades.
- "Buildings can be retrofitted with better windows and insulation to reduce energy waste, and existing fossil-fuel burning systems can be replaced with safer, more energy-efficient options," per Climate Central.


