The Impassable PCT

To hike the Pacific Crest Trail in one season has always been a difficult proposition for all but the speediest of hikers. In the south, one must cross the desert sections before it is too hot, navigate the Sierra after the snow clears sufficiently from the high passes, and complete the North Cascades before the snow starts. Those historical barriers are trivial compared to the unprecedented wildfires that have engulfed the western US. Two days ago, the PCT was closed on all national forests in California, ending the journey for all southbound thru-hikers and section hikers.

This year, I thread the needle by starting at the end of March and hiking some of the northern California sections while the Sierra snow melted. I also covered 22.5 miles per day versus my plan of 17, thereby reducing my hiking time by almost 40 days. These decisions certainly improved my chances of hiking the entire trail. I started facing the effect of fires at Mt. Shasta, and they continued for the next 1,150 miles in Oregon and Washington. The smoke reduced my views and made me nervous, but I did not need to leave the trail. I was lucky. Even before the total closure, north-bound hikers behind me dodged fires in Northern California and had to skip hundreds of miles of the beautiful forests that I hiked only a month earlier. I fear that the 2022 PCT hikers will face hundreds of miles of devastated forests or, more likely, face trail closures in much of California.

What are the experts saying about wildfires?

In August, the Intergovernmental Panel on Climate Change (IPCC) published its 4,000-page Working Group I Sixth Assessment Report on the state of Climate Change worldwide. The IPCC is sponsored by the United Nations and World Meteorological Organization. Chapter 11 of the report discusses “Weather and Climate Extreme Events in a Changing Climate.” What the research and climate models are showing, and what we are all experiencing, is the increased frequency and severity of these climate events. For example, only twice in recorded history have wildfires started on the western side of the Sierra and burned through the Sierra to the eastern side. They are both happening right now. The Dixie and Caldor fires alone have already burned more than 1M acres, and South Lake Tahoe may not survive. The toxic smoke from these mega-fires and many more are causing hazardous air quality eastward for up to 1000 miles.

"It is an established fact that human-induced greenhouse gas emissions have led to an increased frequency and/or intensity of some weather and climate extremes since pre-industrial time, in particular for temperature extremes." (pg 2776, line 17-19)

Compound events, where multiple extreme events of either different or similar types occur simultaneously and/or in succession, may be more probable or severe in the future. These compound events can often impact ecosystems and societies more strongly than when such events occur in isolation. For example, a drought along with extreme heat will increase the risk of wildfires and agriculture damages or losses. As individual extreme events become more severe as a result of climate change, the combined occurrence of these events will create unprecedented compound events. This could exacerbate the intensity and associated impacts of these extreme events." (pg 2889, line 32-38)
     IPCC Working Group I Sixth Assessment Report

What can thru-hikers do?

The first thing is that we need to protect ourselves while hiking on the trail. The Pacific Crest Trail Association (PCTA) has published a page on this very topic, How to react to wildfires. I, for one, was not aware of some of the measures hikers need to take in the presence of smoke. Thru-hikers frequently don’t have mobile connectivity to monitor websites tracking wildfires, and the fires change direction and intensity rapidly. Fortunately, Pleasure-Way was monitoring wildfires and weather and sending me information on my Garmin satellite device. I will write the PCTA and Garmin to see how hikers could be warned more effectively through their satellite devices. Many hikers carry these devices, and it is common to share information and even let hikers who do not have them use them for communication.

All is not lost. The IPCC report outlines how a worldwide effort to cut carbon emissions rapidly to eliminate them by 2050 could cap preindustrial global warming at 1.5 degrees Celsius. Even that best-case scenario means we will experience one new extreme climate event after another. Doing nothing and allowing the global temperature to rise 3 or 4 degrees Celsius will further increase the frequency and magnitude of compound events and lead to the death of countless living organisms, including humans. There is no better example of putting the saying, “think globally, act locally,” into action.