Warming Wednesdays: heat waves ahead

Apparently Mark Twain never said

"The coldest winter I ever spent was a summer in San Francisco."

Oh well -- anyone who has spent time here understands why the thought seems so plausible. It can feel cold and dank in this city, most any time of year, perhaps especially in the summer. Being next to the ocean, we actually experience pretty stable, relatively cool temperatures in the 50 to 65 degree Fahrenheit range most of the time. Compared to people who live with real seasons, we're just coddled weather wimps.

Consequently, I was struck by the emphasis in a new report, "Climate change hits home," from the San Francisco Planning and Urban Research association (SPUR) on projected extreme heat conditions. It took a little digging into the verbiage, but here's what they mean:

Increases in extreme heat, particularly during heat waves, could kill more people than all other climate change impacts combined. Warmer days also worsen air quality, create urban heat islands and can increase people’s risk to vector-borne and infectious diseases such as West Nile virus and Lyme disease. ...

While the Bay Area may not experience the same severity or frequency of extreme heat days as other parts of southern and central California, by midcentury we may see three to four times as many extreme heat days as we do today and six to eight times as many by 2100. In San Francisco, from a 20th-century average of 12 days per year exceeding 81 degrees Fahrenheit, we could have 70 to 94 days exceeding this temperature by 2070 to 2099. ...

... the low-income, the very young and the elderly are the populations most vulnerable to climate change impacts. In large part, these groups’ vulnerability stems from having less ability to anticipate, cope with and/or recover from a disaster.

Temperatures exceeding 81 degrees probably don't seem particularly extreme to many folks. But there is a good reason that they seem extreme here that the new report fails to mention: Older San Francisco houses are scarcely insulated at all. Because our climate is so moderate and unvarying, our older houses mostly didn't come with heat. I lived in this city for over 20 years before occupying a space with central heating. And at the other end of the spectrum, the same unheated houses were built with no more insulation than some old newspapers in the walls.

The massive gentrification over the last 30 years has brought substantial improvements along with rising property values, but many San Francisco houses still lack the amenities that people count on in hot climates. We're going to be in serious shock here with the arrival of many genuinely hot days.



Time to bring on the insulation.