The Slow Unraveling of the Mojave: Climate Change and the Fate of the Joshua Tree
The Joshua tree, composed of two species, Yucca brevifolia and Y. jaegeriana (Asparagaceae), stands as the living symbol of the Mojave Desert, its twisted silhouette with a natural range almost perfectly tracing the boundary of the Mojave ecoregion, which includes Death Valley. But the tree that defines this so-called High Desert is now struggling. Rising temperatures, deepening drought, and a growing list of human pressures are converging to threaten not just individual Joshua trees, but the entire ecological web they hold together.
Joshua Tree: An Ecological Anchor
Our guest, desert ecologist James Cornett from a 2021 interview with Jessica Aldridge, called this special tree a keystone species. In fact, dozens of desert animals and plants rely on the tree’s branching structure, blossoms, roots, inner chambers, and decaying husks to fulfill their life cycles: skipper butterflies, termites, ants, desert night lizards, kangaroo rats, woodrats, and 20 species of birds, including Scott’s orioles, wrens, ladder-backed woodpeckers, and great horned owls.
The Joshua tree flowers exist in an mutually beneficial partnership with a single pollinator, the yucca moth, which lays its eggs inside the blossoms it fertilizes and is the tree’s only means of reproduction. Remove the tree, and that entire cascade of dependent life loses its anchor.
James Cornett shared with us his many decades of studying and writing about desert ecosystems, and what landscape changes we can expect in the future with a heating climate.
Moreover, many other important desert plants and animals face an uncertain future. There exist so many unique symbiotic relationships, from the ocotillo blossoms and migrating hummingbirds to the spiny teddy bear cholla and the innovative woodrat. Some scientists have gone so far as to compare the Joshua tree’s symbolic weight in the desert Southwest to the polar bear’s in the Arctic — both are sentinel species whose decline signals broader ecosystem stress.
A Tree Struggling to Reproduce
The clearest warning sign isn’t dying adults — Joshua trees can live over a century — it’s the absence of young ones. Researchers studying populations across the Mojave have reported seeing far fewer juvenile trees, a sign that something is interfering with seedling survival. Scientists note that seedlings sprouting today face a markedly harsher climate than the one their parent trees experienced when they were young, and it’s unclear how much the species can adapt within a single generation.
Compounding the problem, invasive grasses have fueled wildfires that have burned millions of Joshua trees in just the past five years, while rapid urbanization and energy development continue to shrink the tree’s viable habitat. Long-term modeling adds to the concern: the species’ range is known to have contracted significantly over the last 10,000 years, and current climate forecasts suggest widespread population losses could follow as warming continues.
Desert Tortoises and Solar: Caught Between Two Green Agendas
The same desert now hosts a different climate solution — utility-scale solar — that carries its own ecological toll. Desert tortoises, a threatened species, are frequently displaced from project footprints and relocated, a process far from benign. At the Ivanpah Solar Electric Generating System, biologists initially estimated as few as 32 tortoises on site but ultimately handled and relocated close to 1,000 animals, at a cost of roughly $56 million. Ivanpah is partially closed in early 2026 after Pacific Gas and Electric (PG&E) terminated two of its power purchase agreements due to high operating costs and the rise of more efficient solar technologies. Oops.
To put into perspective solar so-called farms in the Mojave Desert, we turn back to Kim Stringfellow’s Mojave Project. She wrote:
Electricity generation has long been the largest contributor to atmospheric carbon dioxide (CO₂). In response, many countries are shifting from fossil fuels to renewable energy sources that produce electricity with little or no carbon footprint.
At the same time, energy-intensive data centers supporting cloud streaming, artificial intelligence (AI), and cryptocurrency mining are growing rapidly, putting additional strain on the electrical grid. The International Energy Agency (IEA) estimates that global electricity demand from these sectors will double in 2026, amounting to Japan’s annual consumption of 902 terawatt-hours (TWh). To put it in perspective, a single “hyperscale” AI data center can consume from 100 to 1,000 megawatts (MW) of electricity, enough to power between 80,000 to 800,000 homes.
A transformation is underway across the Desert West to meet current and future electricity needs, especially in California and Nevada’s biodiverse deserts, where vast, open areas are being converted into industrial energy zones that previously hosted desert tortoises, kit foxes, and old-growth Joshua trees. View-obstructing transmission lines will crisscross the land, and data centers may follow. This change, driven by a collision of sunlight, technology, and ecology, will be significant and permanent, and is reshaping the desert as we know it.
Relocation of tortoises carries real risk: federal agencies have estimated translocated tortoise mortality at approximately 15 percent, and in one Nevada solar project, dozens of relocated tortoises were killed by predators within weeks of being moved, likely because drought and disorientation left them more vulnerable.
Across the region, tens of thousands of acres of desert tortoise habitat have already been converted to utility-scale solar, and the species has seen a documented long-term, range-wide population decline. Some newer projects have tried to soften the impact — one recent facility raised its perimeter fencing several inches so tortoises could pass underneath, and tortoises have since been observed sheltering beneath the panels — but wildlife agencies still treat large-scale relocation as a serious, only partially mitigated harm.
The Fight Over Water at Cadiz
Threats to the Mojave aren’t limited to heat and habitat loss — water itself is contested. I have been spending a lot of time in the Mojave researching and touring for our High and Dry project on PBS SoCal. We have a two-part photo essay coming out soon, where we looked at the railroad, the alphabetical towns founded to serve water to the steam trains, the Route 66 passage through the desert that followed. The Cadiz Project, also known as the Mojave Groundwater Bank, was summed up well by Julia Sizek and Kim Stringfellow on Kim’s Mojave Project website:
Cadiz Inc.’s 34,000-acre property is located just south of the old Santa Fe railroad line between one of the last undeveloped stretches of historic Route 66. Here, a string of alphabetically named desert towns of Amboy, Bolo, Cadiz, Danby, Essex, Fenner and others were first established as eastern Mojave railroad water stops. Below Cadiz Inc.’s holdings lies the Fenner Basin, an ancient aquifer estimated to hold between seventeen million and thirty-four million acre-feet of water, slowly replenished by infrequent rainfall events occurring in the surrounding federally protected desert mountain ranges. The scarce surface water that seeps into the aquifer through gravitational forces is part of an unfathomable aqueous process that has occurred, largely uninterrupted, for thousands of years. A contentious public-private water grab pipeline may change that.
Trump and his cronies just green-lighted the federal pipeline permit for this project like a zombie that cannot be killed. Indigenous Mojave and Chemehuevi, environmental and conservation interests, and state officials argue the project would draw down the aquifer faster than it can recharge, drying up desert springs that sustain tortoises, bighorn sheep, and Indigenous communities who consider the water sacred.
Statement from Daniel Leivas, Chairman of the Chemehuevi Indian Tribe:
“Our people have been here since time immemorial, and we will not allow the Cadiz Corporation and federal government to destroy the living landscapes that preserve and teach our traditional ways. That is why we are taking this fight for Indigenous rights and cultural survival to the courts. Ocean Woman is the Great Spirit of all water. The cycle and flow of the Living Spirit of water within all the trees, plants, people, animals, land and sky have been present since time immemorial. The ancient waters that formed and shaped the land we know today rest within the Earth below Cadiz. It is the living heart of the desert; to drain it would be to drain the life out of the entire desert. No profit is worth such desecration.”
The original permit pushed for under the previous Trump administration was vacated after a court found it had been approved without the legally required environmental review of groundwater depletion. The project now faces new federal lawsuits over this pipeline spanning more than 200 miles of largely federal land. They are stepping up to defend this region again from the senseless and continuous depredation. The dispute illustrates how, in a landscape already stressed by climate change, even a single water diversion project can ripple through an entire ecosystem.
What This Means for Joshua Tree National Park
Inside the park itself, distribution models have long suggested Joshua trees could lose the large majority of their currently suitable habitat within park boundaries by the end of the century, with the species persisting mainly at higher, cooler elevations that serve as climate refugia. In response, park managers have moved away from simply trying to preserve the status quo everywhere, toward a “resist-accept-direct” framework — deciding where to actively defend existing groves, where to accept inevitable loss, and where to assist the species’ migration into newly suitable terrain.
The long-term health of Joshua Tree National Park will likely depend less on halting change entirely than on managing it deliberately: affording the Joshua tree, and the desert ecosystem surrounding it, time to adapt, migrate, or be helped along by the people who have come to see it as irreplaceable.
Sources:
New Phytologist research on Joshua tree climate adaptation (2025–2026).
National Geographic reporting on Joshua tree climate threats and habitat refugia.
California Fish and Wildlife Scientific Journal population ecology study (2026).
ScienceDirect (Annals of the American Association of Geographers) on green energy development and endangered species in the Mojave.
National Parks Conservation Association reporting on the Cadiz Water Project - Tribal Suit - Ecological Impacts.
USGS/BLM reporting on desert tortoise relocation outcomes at solar sites including Ivanpah and Gemini.
