One of the most efficient ways to get a resident of San Francisco to roll her eyes is to invoke Mark Twain’s description of the city’s summer: it was the coldest winter he’d ever experienced. Twain never actually said this, which is certainly one reason to find it annoying; couple that with a true San Franciscan’s contempt for any corny, touristy aphorism and you’ve got a winner. I would imagine I’ll get a number of emails from city residents who only got through the first sentence before getting so irritated that they needed to reach out.
But! In every misattributed saying there is a grain of truth. And the grain here is that San Francisco’s summers are, in fact, mild. In the morning, you may need a jacket — something that can take visitors by surprise.
Or, at least, that’s usually what summers are like in the Bay Area. This week, that is very much not what they are like.
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“This week was something I’ll call psychedelic heat. Everything slowed down. Reality was questioned.”
This is the assessment of my friend Michael Elliott, who lives in San Jose — a city experiencing an excessive heat warning. I used to live there too, in an apartment that, like his house, had no air conditioning. You just didn’t really need it that often. Even when it got hot, it would cool off at night, daytime heat dissipating into the cloudless sky.
This week, this summer, has been different. The heat seen throughout California has been exceptional.
In 2020, the San Francisco Chronicle reported that the percentage of homes in the Bay Area with air conditioning had risen from 36 percent in 2015 to 47 percent only four years later. The rise was attributed to “changing weather patterns” — which, of course, is broadly a euphemism for climate change. No individual weather event can easily be linked to climate change, but the recent heat seen across the west is consistent with a warming world.
According to 2020 data compiled by the Energy Information Administration (EIA), there are about 18.5 million households in the Pacific region: California, Washington, Oregon, Alaska and Hawaii. Only 12.6 million have any form of air conditioning — the lowest of any census region.
We’d expect Alaska to have fewer air-conditioned homes. But California makes up a disproportionate percentage of the region’s total. In 2019, California was the state with the highest percentage of homes without air conditioning in the continental United States.
Increasing the number of households with air conditioning does address the problem of keeping people comfortable — and safe — during heat spikes. But it introduces a new problem: electricity consumption. That Chronicle article quoted a climate-change assessment, which noted the increased electricity demand that the increase in air conditioner usage had prompted.
This week, California sent out a text message calling on residents to conserve power as the heat drove up usage. It worked. But notice the key line in Gov. Gavin Newsom’s (D) call to action: keep your thermostats set high.
CALIFORNIA: We’re now in a Flex Alert.
What does that mean? We all need to conserve as much energy as possible during this record breaking heatwave.
Here’s what to do until 9pm tonight:
– Set thermostats to 78
– Turn off unnecessary lights
– Avoid using large appliances
— Gavin Newsom (@GavinNewsom) September 7, 2022
California is exceptional in that its moderate climate has made air conditioning less necessary. (According to the EIA, only about half of households in “marine” climates have air conditioning, compared to 88 percent of homes in “cold” or “very cold” climates.) But in much of the country, the lack of air conditioning is more closely correlated to income.
In 2020, about a quarter of households with an annual income of less than $5,000 had air conditioning. About 16 percent of households with incomes of under $40,000 had no air conditioning (which comes out to about 7 million of 43 million total homes). Only 7 percent of households with incomes at or over $100,000 (about 2.5 million out of 33 million nationally) don’t have air conditioning.
The effects of climate change continue to expand. A new report estimates that, within 30 years, a third of the country may experience at least one day a year with a heat index — that is, how hot it feels — of over 125 degrees.
That probably means more air conditioning, which means more electricity consumption (and higher electricity bills). It also, for now, often means more release of carbon dioxide or methane into the atmosphere where the molecules can trap escaping planetary heat.
By 2050, San Francisco may see average summer temperatures 3 degrees warmer than it did 20 years ago. Of course, in a warming world, that may still qualify as winterlike frigidity.