Life under the heat dome: You might no longer know where you are

Tony Hiss’s new book is Rescuing the Planet: Protecting Half the Land to Heal the Earth.

Was the Pacific Northwest heatwave at the end of June a glimpse into what North America will be like by 2050, after another three punishing decades of rising temperatures? Even weeks later, searing images from the seven days of the “heat dome” linger – the charred remains of the town of Lytton, B.C., 90 per cent destroyed by fire one day after experiencing Canada’s highest ever temperature, 49.6 C. Simultaneously, more than 100 kilometres to the southwest, on the scorched beaches in and around Vancouver, low tides exposed mussel beds to 42 C heat for six hours at a time – all told and all at once an estimated billion mussels, clams, barnacles, sea stars and hermit crabs boiled and baked to death.

Unlike the familiar image of the frog in a saucepan ignoring the gradually heating water, this was sudden and inescapable. Christopher Burt, a weather historian, calls it “the most anomalous extreme heat event ever observed on Earth since records began two centuries ago.” According to 27 international climatologists at World Weather Attribution, “it would have been virtually impossible without human-induced climate change.” Washington State climatologist Nick Bond recently said that the real surprise is that heat like this is here already: “It blows my mind. … I would have been willing to guess something like that in the middle of the century, in the latter part of the century.”

Also trying to peer ahead through the coming years of intensifying heat are ecologists and conservationists. They’re already publishing jarringly precise predictions about what you could expect by mid-century or at the dawn of the 22nd century in some of the continent’s best-loved places, such as the Greater Yellowstone Ecosystem (meaning the larger landscape 10 times the size of the iconic national park it surrounds). Their most shocking conclusion: You might no longer know where you are.

Old Faithful, the world’s most famous geyser and Yellowstone’s heartbeat, which now erupts about 17 times a day, may shut down altogether. Researchers at Montana State University say this happened 800 years ago during an earlier period of intense heat plus drought. Furthermore, according to an article by seven German and American climate modelers published one month before this summer’s Pacific Northwest heatwave, between 28 per cent and 59 per cent of the Greater Yellowstone forests will no longer be able to replace themselves, leading to what these scientists call a “reassembly of the biosphere” and “lasting transitions to a fundamentally different state.” Such brand-new combinations of plants and animals are so unlike anything we’ve seen before, they can be thought of as novel ecosystems with no analogue anywhere.

Often called the birthplace of conservation, Yellowstone, 151 years ago, became the world’s first national park, and Greater Yellowstone still has much of the same majestic presence as it did when Native Americans discovered it more than 10,000 years ago: It’s a home for wolves (though they had to be reintroduced), grizzly bears, the continent’s largest elk and bison herds, and vast swaths of forest. From the start, fire has actually been a principal pillar of this persistence – “an essential reason,” as Mary Ann Franke, a National Park Service writer and editor, put it, “why Yellowstone looks the way it does.”

This was demonstrated by the park’s prompt response and vigorous regrowth after 248 fires ignited during the summer of 1988, and made headlines by burning more than a third of the park. On a single August day, later called “Black Saturday,” fire consumed 150,000 acres and smoke columns rose 20,000 feet in the air. Twenty-five thousand fire fighters from around the U.S. came to help douse the blazes.

Within a year recovery and renewal were well under way. Botanists pointed out that some lodgepole pines, one of the most prominent Yellowstone trees, are unable to regenerate until after an intense fire has come and gone; their pine cones are sealed with thick, waxy resin that can only crack open in the heat of 45 C flames. By 1993, Monica Turner, an Oak Ridge National Laboratory researcher, could report seeing burned-over areas where “the number of established seedlings is eight times as large as the original number of trees.”

The seven German and American prognosticators of Greater Yellowstone’s future agree – the area is fire-tolerant and in some ways fire-dependent. The problem is that it is, more precisely, “well adapted to infrequent, severe fire.” Specifically, to fires that recur every 75 to 100 years at lower altitudes, and to higher elevation fires at 100 to 300 year intervals. But since 1982 temperatures in the region have gone up by 2.5 C – and are still climbing. From this the scientists draw the inference that “weather conditions conducive to large fires as in 1988 could become 10-20 times more frequent by the end of the century.”

Since, as they point out, it takes 30 years after sprouting for many tree species, even fire-friendly ones, to be ready to produce yet another generation of seedlings, the grim prospect is what they call “widespread regeneration failure in forests of Greater Yellowstone.” With, as they say, “profound implications” for biodiversity and recreation.

For a remedy I turned to Reed Noss, a conservation biologist who for decades has been thinking at a continental scale. In 1992 he was one of the first scientists to say we’ll have to set aside half the planet to stave off the biodiversity crisis that threatens a million species of plants and animals with extinction. “Rewilding in the face of climate change,” his most recent paper, co-authored with Carlos Carroll, talks about protecting more of the enormous, binational Yellowstone-to-Yukon landscape.

Reached at his home in Florida, we talked about this intersection of the biodiversity crisis and the climate crisis. Dr. Noss said that conservationists have for years assumed that as the Earth warms, many species will retreat northward and to higher altitudes. But if warming is accelerating, then lots of things come into play. Yellowstone may itself turn into a novel ecosystem where cheatgrass, an invasive species, would replace vanished forests. Unlike most native grasses, cheatgrass doesn’t grow in bunches, which leaves room for other plants.

The encouraging news is that some native grasses seem to be adapting both to cheatgrass and to more frequent fires. These grasses need to be closely monitored and encouraged. In the Yellowstone of today, instead of thinking about “hotspots,” meaning areas known to be essential for the survival of various species, we can be on the lookout for previously unconsidered areas that turn out to be even “hotter spots.” We can pinpoint places – say on steep north-facing slopes – that never ignite, or burn less fiercely. These places can be set aside as “fire refugia,” safe havens for trees like Engelmann spruce that tend to be badly damaged by wildfires.

“Now that we’re forewarned,” Dr. Noss says, “we have a little time to get more nimble, and press forward with a ‘no regrets’ strategy.”

By looking ahead beyond disaster, beyond tomorrow’s suffocating heat and fires, we can look forward to a time when we can still look around and know where we are.

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