17: California's Climate

Introduction to California's Climate

It was a warm Sunday morning on 15 August 2021 as the four members of the Gerrish-Chung family set out on a moderate hike near their home. Covid pandemic remote work allowed the family to relocate from the Bay Area to the bucolic foothills of the Sierra Nevada, in the town of Mariposa, close enough to Yosemite that the El Capitan monolith was visible from their house. This active family familiarized themselves with their new home by completing numerous local hikes, and were so well prepared for these sojourns that in addition to a generous 85-ounce water supply, they even carried a snakebite kit. 

Two days later, authorities discovered four bodies exposed on a trail. Jonathan Gerrish, 45, Ellen Chung, 30, their one-year-old daughter Miju, and Oski, the family dog, were found just a mile and half from the top of a trail leading down to the Merced River. 

Authorities were perplexed. There were no obvious signs of foul play or animal attack or suicide. They did not appear to have been struck by lightning. Toxicology discovered no signs of drug overdose. In the absence of an explanation of four seemingly-healthy individuals suddenly dying all at once, strange speculations abounded: perhaps they succumbed to toxic algae from the Merced River, perhaps a cloud of carbon dioxide released from an unknown Gold Rush-era mine and asphyxiated them. With no plausible explanation, authorities closed the area as a potential hazmat situation.

Police investigations stalled because of passcode-protected cell phones; however, once the FBI gained access to Jonathan Gerrish’s cell, a clearer picture emerged. On that Sunday, the family awoke early and started their hike by 7:30 am, when the outside temperature was just 24^oC (76^oF). Gerrish’s AllTrails app revealed a plan to descend to the Merced River, then return via another trail by 1 pm, before afternoon temperatures rose. They took the first selfie at 7:44 am. They reached the river and took a selfie at 9:05 am. By 10:29 am, they were ascending the trail toward home.

We will never know the full details of what happened next. But one stark fact remains: though the day’s hike began with moderate temperatures, by late afternoon the exposed trail would have reached 42^oC (109^oF). Radiant heat from rocks and soil would have made it even worse. Moreover, this trail had been denuded of vegetation by a massive wildfire three years earlier. Fires of this kind are more common in California because of climate change-induced drought. Because of this earlier conflagration, the family had virtually no shade or relief from the increasingly sweltering sun. The unlocked cell phone revealed desperate attempts to call and text for help, none of which went through because of the lack of cell service.

Heatstroke can kill anyone–the young, the fit, the well-hydrated. For example, one would imagine that teenage athletes would be able to cope with exercising in high temperatures. But at least 50 high school football players are known to have died of heatstroke brought on by games and practices. Fans of the Harry Potter movie franchise may remember the character of Fenrir Greyback, the cannibalistic werewolf aligned with He Who Must Not Be Named. What such fans might not realize is that in 2014, the actor who played the werewolf–David Legano, a fit 50-year old professional martial artist and athlete–went on a solo day hike near Zabriskie Point in Death Valley and died of heatstroke. A month before the Gerrish-Chung family’s deadly hike, a 37-year-old ultramarathon runner named Philip Kreycik died in Pleasanton, CA, while on an easy nine-mile loop he expected to complete in under an hour; the estimated outside temperature during his run was as high as 41^oC (106^oF).

It was not foolishness that doomed the Gerrish-Chung family. In a normal world, they would have no reason to expect that a moderate hike begun with moderate temperatures would transform into a life and death struggle. But this is the new reality for California’s new climate. Our experience of playing outdoor sports, of leaving a pet in a car for a few minutes to run into a store, of taking a mild family hike on a sunny day, all of these expectations are now wildly out of calibration with the lethal climate change our state faces.

This chapter investigates the phenomenon of California’s climate in three ways. First, we examine the past climate history of California, which reveals that extremism is the norm rather than the exception. Second, we focus on what is currently happening, especially in regards to the rising temperatures threatening the fragile liveability of this parched state (see Figure \(\PageIndex{1}\)). Lastly, we explore projections for our grim future in a warmer, deadlier California .

References

1. Adams, A. (2021, December 5). New Information Emerges in Report Detailing Deaths of Calif. Family of 3 Who Died on Hiking Trip. People. https://people.com/human-interest/john-gerrish-ellen-chung-family-hiking-deaths-miju-dog-oski-update
2. Anguiano, D. (2021, October 21). California family found dead on hike killed by extreme heat, sheriff says. The Guardian. https://www.theguardian.com/us-news/2021/oct/21/california-family-hike-cause-of-death
3. PBS Newshour (2022, July 20). How extreme heat affects young athletes. Retrieved October 4, 2023, from https://www.pbs.org/newshour/science/how-extreme-heat-affects-young-athletes
4. Gander, K. (2014, July 14). Dave Legeno dead: Harry Potter actor found in Death Valley. The Independent. https://www.independent.co.uk/news/people/dave-legeno-dead-harry-potter-actor-found-in-death-valley-9601652.html 
5. Larson, A. (2021, August 27). Pleasanton runner Philip Kreycik likely died from heatstroke in 106-degree weather, investigators say. Retrieved October 4, 2023, from https://www.kron4.com/news/bay-area/pleasanton-runner-philip-kreycik-likely-died-from-heatstroke-in-106-degree-weather-investigators-say/