San Francisco Chronicle - (Sunday)
Warming planet increases danger of outdoor jaunts
The temperature reached 109 degrees, investigators believe, when Jonathan Gerrish and his wife, Ellen Chung, hiked with their 1-yearold baby and dog earlier this month along a remote Mariposa County trail.
It was as hot as 106 on July 10 when ultrarunner Philip Kreycik went for a jog in the Pleasanton Ridge Regional Park.
The thermometer hit 108 on Aug. 18 along the Golden Canyon Trail in Death Valley National Park when 60-year-old San Francisco resident Lawrence Stanback braved the heat for a hike to the Red Cathedral.
None of them survived their adventures. Investigators believe heat played or may have played a role in their deaths.
As temperatures continue to rise in Califor
nia and elsewhere because of climate change, state scientists warn that there will only be more opportunities for heatrelated illness or death while residents enjoy the outdoors. The dangers will only increase.
“Everyone is high risk when it’s so hot outside,” said Rupa Basu, the chief air and climate epidemiologist with California’s Office of Environmental Health Hazard Assessment.
Two years ago, Basu and her team published the Climate Change Indicators Report, which, among other findings, determined that the risk of death increased with rising average temperatures. The warning stressed that certain groups — such as the elderly, young children, those with pre-existing health conditions and the economically disadvantaged — were at higher risk.
“Those engaged in vigorous physical activity outdoors ... are also at greater risk,” the study found.
Since 1950, extreme heat days from April to October in California have increased at a rate of about one extreme heat day per year, the study found. That rate has hastened in the past 30 years. On extreme heat days, temperatures are at or above the highest 2% of historical daily highs, while on extreme heat nights, they are at or above the highest 2%of historical daily lows.
Extreme heat nights, which have increased even faster than days, can make it harder for people to cool down during hot weather, the researchers said. That can affect higher-risk people including the elderly.
“Over the last 20 years, every year is hotter than the last, more or less,” Basu said. “That’s part of the reason from a health standpoint why we need to be proactive because it’s changing so quickly.”
Heat causes more reported deaths annually on average in the U.S. than any other weather hazard, according to the report. And that’s despite heat illness and death being “severely underreported,” Basu said.
In 2006, a heat wave in California led to at least 140 deaths from July 15 to Aug. 1, more than 1,100 hospitalizations and about 16,000 emergency room visits.
Earlier this month, Stanback died a little more than a mile from the Death Valley National Park trailhead, which has a large warning sign saying, “Stop — Extreme Heat Danger — Walking after 10 a.m. not recommended.”
Nine of Death Valley’s 10 hottest summers have been recorded in the past 15 years, said park spokesperson Abby Wines. Typically, she said, the park has one heat-related death every year or two, but it has seen three so far this summer.
“This particular summer has been really bad,” Wines said. “But the vast majority of our heat issues are not on the highest days.”
That’s because when the thermometer hits 130 degrees, like it did earlier this summer, visitors step out of their cars and immediately jump back in.
What also complicates matters are California’s microclimates, Basu said. The thermometer jumped from a high of 64 degrees in Berkeley on July 10 up to 106 when Kreycik decided to go for a jog 30 miles away in Pleasanton.
Despite his experience as a distance runner, GPS data from his smartphone indicates Kreycik experienced trouble after 5 miles, probably because of heat exposure, an Alameda County Sheriff ’s Office spokesman said. His body was found weeks later under a tree.
Investigators are still waiting for autopsies to come back with toxicology reports for the young and fit Mariposa family to determine what killed it and its dog. But they are already suspecting an amalgam of climate change impacts could have played a role.
Authorities believe the family left for its hike during an extreme heat day with temperatures of 103 to 109 degrees in the afternoon, under smoky conditions caused by another historic wildfire season. The 2018 Ferguson Fire burned down much of the vegetation along the trail, eliminating most shade along the grueling, 8½-mile steep loop.
Detectives also have raised concerns that the family could have come in contact with toxic bacteria in the waterways along the hike.
Such freshwater blooms have taken hold in recent years, said University of Southern California biological sciences Professor David Caron. Climate change, particularly drought and hotter water, exacerbates such toxic blooms, he said.
“Freshwater is a little more of the Wild West,” Caron said. “This is something that’s come onto our radar in the last five, six, seven years.”
The bacteria can create toxins that can kill humans and animals. The U.S. Forest Service placed signage at the trailheads, warning hikers, among other things, not to drink the water or eat shellfish.
In addition to more extreme conditions, there are just more people out in the heat. People are visiting national and regional parks in record numbers as they look for outdoor recreation amid a pandemic. From 2014 to 2016, the National Park system saw 16 heatrelated deaths. Basu, whose group plans to release an updated climate report this year, said society should be proactive ahead of the new dangers. Perhaps closing down trails when temperatures surpass certain thresholds or increasing public education, she said.
“Communities with such measures will be
“Everyone is high risk when it’s so hot outside.” Rupa Basu, chief air and climate epidemiologist with California’s Office of Environmental Health Hazard Assessment
better able to protect against heat-related illnesses and deaths as California continues to warm,” the study found.