Human-caused climate change is putting the squeeze on Mojave Desert species
To know a place truly is to know it in all seasons. I remind myself of this maxim as I blink sweat out of my eyes, hunched over a PVC pipe jutting out of the grooves of a vast salt flat, coaxing an electrode below the earth’s surface. The sun floats high over rippling ranges of black rock. The mass of dry air filling the Amargosa Valley shimmers. I’m checking shallow monitoring wells to understand flow trends in a wetland near Death Valley Junction. It’s lonely, exposed work — work that ensures the endangered plants that call this place home will have the water they need to withstand the extreme summer.
Summer in the Mojave Desert reminds human beings that this landscape, for all its beauty and allure, is not known for its softness. The heat and aridity are real, as heavy and constant as gravity. Summer is the great bottleneck that dictates who stays and who goes in these lands: which species have the cleverness, frugality, and downright toughness to make it to autumn, and which do not. Millenia of seasonally extreme heat and aridity have shaped the ecology of the Mojave into its contemporary form. It’s an ecology of thrift, in which the greatest currencies are shade and water.
In these terms, the Amargosa River is a treasure trove for many species that depend on surface water and vegetative cover. The river flows from the mountains of western Nevada south into the Mojave Desert, running 186 miles above and below the surface before coming to rest in Badwater Basin of Death Valley National Park. The Amargosa River supports a network of oases that act as bastions against the raw heat of the desert for birds, mammals, fish, and amphibians, many of whom have evolved into distinct species as a result of prolonged isolation from their nearest relatives. In a very real sense, the incredible biodiversity of the Amargosa Basin is a direct result of the bottleneck’s severity.
But the bottleneck is constricting. Anthropogenic climate change is attenuating the range of many species’ survivability by pushing the summer seasons into a higher gear. Heatwaves in the Southwest are occurring earlier in the year and lasting longer than historical patterns reflect. The 20-year drought has stretched so far that many suggest we stop using the term “drought” altogether. Drought is the new “normal.” Phasing out the use of the term drought, really, is accepting the reality that climate change is pushing landscapes into a new state of being and that a return to the previous state of being is improbable given the trends of warming and emissions. In the Mojave, this means recognizing the narrowing bottleneck.
Researchers have recently reported increased mortality rates of species found both in Death Valley’s highest ecological zones and its lowest. An article in the Los Angeles Times documented the death of bristlecone pines on the shoulders of the White Mountains, marking the end of lives that have weathered more than 1,000 years of extreme heat and cold. Drought and warming conditions have led to a steady rearranging of the alpine forests in many parts of the U.S., as they’ve allowed upslope migration of tree species historically unable to survive the cold of higher elevations. As the trees climb, they transport pine beetles into populations that are traditionally preserved from and thus vulnerable to them by the buffer zone of non-beetle carrying pines. It’s resulted in the slow death of bristlecones, some of the oldest and most resilient lifeforms on planet Earth.
In the lower reaches of the Death Valley region, scientists have observed mortality of creosote, a species well-known for its resilience: in years where little else blooms or shows signs of vitality, creosote often finds a way. This is unsurprising, given that creosote was one of the early species to populate the Mojave after the last ice age, when the lakes receded, and the climate changed. But every species, no matter how frugal and tenacious, has a breaking point. And we’re starting to see the early signs of impending ecological collapse, as the bottleneck tightens, pushing species into a fight for their lives.
There are signs of hope. In June, I went to a leadership training in Las Vegas hosted by The Climate Reality Project, an organization dedicated to giving people the knowledge and tools they need to fight for a sustainable future. About 400 people attended, joining a community of artists, advocates, scientists, business leaders, teachers, students, and representatives from virtually every walk of life in the fight to rein in the climate chaos created by industrial societies. Most striking was the proportion of BIPOC and Gen Z people, two demographic groups that will be the most affected by the negative effects of climate change. While conversations about Tribal relations, environmental racism, water scarcity, and the responsible transition to renewable energy were being held in every corner of the conference room, a record-breaking heat wave raged across the Southwest just outside the walls.
It can be traumatizing to witness the casualties caused by humans pinching the bottleneck, and in truth we are still in the early days of what will be an awful and protracted degradation of the natural world by anthropogenic climate change. But despite that, there was a vein of contagious optimism running through The Climate Reality Project gathering. The name itself provokes us to accept that climate change is indeed our new reality. To accept this is to accept that using terms such as “drought” or “abnormal heatwave” is to irrationally cling to a past chapter of the planet on which the page has been irrevocably turned. A realist’s perspective is one that accepts the situation we find ourselves in and challenges us to do whatever we can, as quickly as we can, to change the course of human history in a direction more aligned with the limits imposed by the landscapes we inhabit.
This is what I ponder as I move slowly across a lonesome stretch of the Mojave, wilting a little under the summer sun. If shelter and water are the greatest currencies here, how will we conserve them? How can we invest our resources to support the species that depend on the steady presence of water and shade? How can we fortify these desert bastions that human and nonhuman communities call home against increasingly ferocious heat and aridity? And how can we ensure that this new age of conservation is guided by the communities that have historically lost the most and stand to lose still more? These are the questions that push back against the narrowing of the bottleneck.
I’m beginning to know this place truly, I remind myself, shielding my eyes against the sun in my search for another lonesome PVC pipe monitoring well. I walk on, endangered species underfoot, heat working on me like a hammer. I hope that I, too, can make it through the bottleneck. Φ