Temperature’s Rising, It Isn't Surprising… But Surely Alarming

In the musical romance “There’s No Business Like Show Business,” Marilyn Monroe sang “Heat Wave,” crooning in her signature breathy voice: “the temperature’s rising, it isn’t surprising….”

It's a song that's gotten stuck in my head nearly every heat wave since I was a pre-teen growing up in Southern California.

The year Monroe sang that song was 1954 — it was timely because that summer record-breaking heat swept the Midwest.

But that heat wave was a natural anomaly. UCLA climate scientist Daniel Swain says our current heat wave has a human fingerprint.

“It's becoming easier and easier to hit temperature thresholds that were historically difficult or impossible to reach in a cooler climate, unaffected by the human emission of greenhouse gasses into the atmosphere,” Swain said.

Temperatures Will Be Far Above Normal In The Coming Days

If you’ve lived in Southern California a while, you know September is one of our hottest months. But this weekend, heat records are likely to be broken across California.

According to the California Independent Systems Operator (CAISO), the non-profit agency that oversees the state’s electric grid, temperatures in Southern California are expected to be 10 to 18 degrees warmer than normal. In northern California, temperatures are expected to be 10 to 20 degrees warmer than normal.

Swain said the evidence of global climate change affecting this heat wave isn’t just in the record highs, but also how long this heat wave is expected to be and how much of the state it covers.

The climate crisis is also making extreme heat more frequent, particularly this time of year in California. “The autumn is one of the fastest warming times of year in much of California, especially in the coastal and valley regions,” Swain said.

Climate projections show that by 2040, coastal areas and central Los Angeles could experience three times more days with temperatures over 95°F. The San Fernando and San Gabriel Valleys are expected to have even more dangerously hot weather.

And higher temperatures predicted at night, particularly in the foothills and inland areas this weekend, are another sign of how the climate crisis is exacerbating heat overall and interacting with our asphalt- and cement-heavy built environment … a dangerous, and potentially deadly, combination.

Extreme Heat Is Hazardous To Your Health

“The cumulative heat stress from those very warm overnight temperatures and extremely hot daytime temperatures combined are potentially going to cause quite a lot of human health adverse effects,” Swain said.

That long-running extreme heat makes day and night hard on our bodies. It’s especially dangerous for those who don’t have a safe place to cool down, such as those who are unhoused or live in substandard housing.

And with the extreme heat forcing most everyone to crank up the A/C, the grid is extremely strained, according to CAISO. That’s why the agency issued its first Flex alert of the weekend, calling for voluntary energy conservation use from 4 pm to 9 pm tonight. (Read this story to understand why abiding by those flex alerts matters.)

The 10 warmest years on global record have all occurred in the 21st Century. And 2022 may end up on that list.

Global temperatures have increased about 1.2 degrees Celsius since the Industrial Revolution. If emissions continue on their current track, that temperature is expected to hit 3 degrees C by end of century. The global goal is to limit warming to 1.5 degrees C. (Here's more on what that all means for L.A.)