A young science teacher told me recently that her students want to learn more about ways to find hope when their future is threatened by climate change. This spring, that threat was felt more keenly as April’s Tunnel Fire quickly destroyed people’s homes, adding to the long list of increasingly severe wildfires that are reshaping our lives.
Why do these fires continue? The reasons are familiar to most northern Arizonans: drought, wind, and dense forest fuels. Helpful actions such as the Four Forest Restoration Initiative (4FRI) are critically important, but even they cannot completely eliminate large fires.
Finding hope for the future starts with a realistic assessment. We know a lot about forests – the Fort Valley Experimental Forest is the US Forest Service’s oldest research forest, and forestry science has deep roots in Flagstaff. The science of tree-ring analysis, developed by Andrew Douglas in Flagstaff over a century ago, shows the close links between climate, growth and fires. We therefore know that the future forests of our region are likely to change very rapidly with the current global warming.
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A pervasive myth about climate change is that it happens slowly. If the average temperature is rising by fractions of a degree per decade, why worry? Our current drought, estimated to be the worst in 1,200 years, is causing a slow decline in tree growth, greater susceptibility to insect attack and death from lack of water. But drought also brings rapid change as parched landscapes burn within days or weeks. Global warming is not just a slow change in average conditions, but greater variability and extremes, from droughts to fires to floods.
The future climate is not fixed. The Earth is warming, but how far it goes will depend on human actions. How far and how fast will the world’s societies move away from fossil fuels? Even in the “best case scenarios” envisioned by climatologists, the Southwest will continue to warm and experience many dry La Niña-like winters in the years to come. Widespread species such as ponderosa pine may not disappear immediately, but are likely to become rare in the elevation range of 7,000 to 8,000 feet. If you want to imagine Flagstaff around 2040, think of Prescott today. High-altitude ecosystems such as aspen, spruce, and fir, and their associated plants, animals, and microbes, are less likely to persist.
Adaptation to warmer, drier conditions is inevitable. In a sense, severely burned landscapes actually adapt by eliminating plant species that require cooler, wetter conditions. A tour of burned areas northwest of Flagstaff, such as footprints from the 1996 Horseshoe Fire off Highway 180 or the 2010 Schultz Fire on the east side of the San Francisco Peaks, reveals that pine regeneration is so limited that the forest is unlikely to return. .
On the Rodeo-Chediski fire that burned 20 years ago, the sprouting alligator juniper and Gambel oak that dominate the regrowth landscape are likely to sustain the fire again soon. But adaptation through wildfires comes at high costs as lives, homes and habitats are threatened and topsoil that has accumulated over millennia is washed away to fill reservoirs.
The most encouraging thing we can do is to act, based on the best knowledge available. The 4FRI project and similar efforts are critical: clear evidence shows that tree thinning and prescribed burning reduce the effects of wildfires. Many Native American communities are leading the way in fire reintroduction, including fire restoration by the 60-year-old Hualapai Tribe and landscape-scale fire management by the San Carlos Apache Tribe. Grand Canyon National Park and our Southwest National Forests have also been leaders in fire restoration. Scientists at the NAU and elsewhere are studying the characteristics of different tree genotypes and species adapted to warmer conditions. Some species that extend south and into Mexico are being evaluated for use in replanting when native trees die.
Support for all forms of action to reduce greenhouse gas emissions from the local to the global level is also essential to hope for a “best case” result. Future generations will also need forests. Thoughtful and persistent stewardship is needed to help us and all ecosystems adapt to a warming climate.