“He was born, he said, far down the Yukon River, at the mouth of the Kandik, in 1913. ‘They kept on moving in those days. They don’t stay in one place. They lived off the country. They lived in big tents, ten by twelve, the biggest they ever had. they just keep on moving. They don’t stay in town all the time, like we do.’” — excerpt of a Hungwitchin elder’s reminiscence, from John McPhee’s Coming Into the Country [Farrar, Straus and Gireaux, 1977].
John McPhee’s inquiries in Alaska are a nuanced portrait of how Alaskans came to be where he interviewed them. Many were from more crowded lands, with less opportunity for the types of challenges their new habitat posed. I pulled the above quote from an elder remembering a time when humans followed seasonal animal migrations, and seasonal access was more valued than owning houses and property — because by the 1970s it was already obvious to some Alaskan Natives that the new ways were not matching the land’s limitations. It’s a lesson we would do well to consider in our own home regions. When weather events (be it flooding, wind, heat wave, drought, warming, cooling) become a series of disasters beyond management capabilities, some members of some species adapt by migrating into newly usable habitat, while others adjust to a changing familiar. Until now, humans seem to have succeeded by employing both strategies, to the point of recently reaching a record worldwide population density of over 8 billion individuals with seemingly no consensus forming on how many will be too many. As our home planet reshapes its habitat boundaries to match new climate realities, it’s worth considering that species neither adapting in place nor moving to suitable habitat tend to die out over time.
A recent study measures the chemical signatures of sediment from the Arctic Ocean deposited before and throughout the Last Glacial Maximum (ca. 26,500 to 19,500 years ago). It estimates the timing of a land bridge connecting Eurasia to the Americas to be a 20,000+ year period ending 11,000 to 13,000 years ago, with humans likely beginning to expand into the newly accessible North American continent soon after the Bering Land Bridge was exposed by receding ocean levels.
Here’s another quote, “Humans have an amazing ability to get to places.” This one is from a geneticist at Stockholm University, Anders Götherström, commenting on recently published research using genetic information to propose that as glaciers receded and sea levels rose to refill the Bering Strait, humans continued migrating back and forth between the Eurasian and American continents. Both of these studies illustrate promises and challenges that face all species in times of climate shifts.
As humans migrated to the south and east along the edges of receding glaciers, some found the dry lands of interior North America to their liking enough to stay and adapt to the new habitat, according to archaeological evidence of human-made structures placed to control water in dryland streams. This is where our species’ ancient ways intersect with some current efforts to adapt to a multi-decade drought that has become the aridification of many dryland regions, as seasonal wildfires, flooding and erosion further damage already challenged riparian areas and aquifers. Below is a stylized depiction of ways long employed by desert dwellers to slow water flows enough to create wetland-like riparian areas, building soils behind the structures and allowing vegetation to grow and prevent erosion, absorb carbon and create habitat for other species to use.
Together, the methods are known as “Natural Infrastructure.” In my decades on the drylands, I’ve at times used several of these with good results, and have studied others that long out-lasted the houses and lives of the ranchers and farmers who built them. As Colorado River flows diminish year by year, this is a time when once again, seemingly serious humans are proposing to tap faraway river systems to allow more dryland development. Here’s a hint of a possible problem — click Drought and Barge Backups on the Mississippi for NASA images of another river with no water to spare. It seems a better course might be to apply ways humans have previously adapted to climate realities. In the Chiricahua Mountains of southeast Arizona, two ranchers have installed thousands of rock dams and other riparian structures to re-green an overgrazed, desiccated creek drainage. The ongoing effects of their labor are being studied by USGS scientists for insights into building infrastructure that works with a landscape’s natural elements and climate, and the video is a timely antidote to stories of dread and desperate measures to prolong unsustainable practices. Clicking the link in the caption below the image will take you on a 10-minute exploration:
Migration and innovation are two aspects of one survival strategy for the human species. In their stories of those who came to Alaska, those who left, and those still moving with the times, John McPhee’s interviewees confirmed this — whether coming into a country or native to it for many generations, the best way to stay is to adjust expectations, practice old ways and new skills, and innovate for changing conditions. Up next, New Grid, Off Grid — a journey through a Wilderness of Wires. Until then, take care of yourself, help somebody else along the way, and enjoy this animation of how to regenerate your way to climate resilience! - B.