Their summer is our winter. In the south of the United States, it is the “beautiful season” that we spend indoors. The one where the parents watch when the little ones play outside. The one where you have to take the elements into account when working outdoors, when a humid 42°C can be as dangerous as -20°C. It must be said that from the Pacific coast to the desert, from Colorado to the Prairies, the central and southwestern United States have always posed challenges for the populations who live there. Because these regions regularly experience cyclical droughts. Of those that could last a year, or ten. Of those who could change social structures.
The terrible story of dust bowl is here to remind you. At the beginning of the XXand century, a series of economic and political events brought thousands of Americans to the confluence of Kansas, Oklahoma, Missouri and Texas to farm the plains of the American Southwest, where prairie grass was once so thick that it only suited bison. But this human adventure came to an abrupt halt when a succession of droughts hit the plains beginning in 1931 — and for a decade — causing a veritable climatic cataclysm: when farmers were no longer able to cultivate the land , too dry, they left harrowed, bare fields exposed to hot, dry winds.
The constant squalls swept away the eroded land in monstrous clouds of dust. For a decade, these “black blizzards” silted up prairie farms and occasionally darkened the skies of the Atlantic coast. The return of the rains in 1940, the adaptation of plowing methods and the drilling of wells in the water table of the Ogallala put an end to this sad episode. For a time. Because climate change changes the situation by multiplying the phenomenon of cyclic droughts. The evolution is already palpable. In Arizona, the city of Phoenix collects temperature records. California burns season after season, and ever earlier each year. But it is the Colorado River, the lifeline aquifer of Las Vegas, Phoenix and Tucson (and accessory to Denver, Salt Lake City, Albuquerque, Los Angeles and San Diego), the motor of agriculture, from Arizona to the ranches of the Wyoming, and key to hydroelectric production, officially in crisis.
For the first time in US history, there is
10 days, the US Bureau of Reclamation chose to postpone the barrage releases. Between May and July, in principle, the Colorado is replenished by the melting of the snowpack upstream. Today, the dry soils drink up the meltwater, which does not reach the river. Harnessed, hijacked, pumped, the Colorado is no more than a shadow of itself: its level is at its lowest. With cascading effects. On electricity production, which could become unpredictable. On access to water for consumers downstream: exactly 100 years ago, the States bordering the river shared the rights to this water windfall, but today, this sharing no longer corresponds to the realities of the river. Some communities could be rationed or even deprived of access to water.
In the west and center of the country, it is no longer possible to remedy the drought by frantically pumping the water tables as we were able to do to get out of the episode of dust bowl : they too are contracting – whether it is the aquifer of Memphis Sands, that of the Central Valley or the immense water table of the Ogallala. Their disappearance by the end of the century, explains the United States Geological Survey (USGS), will threaten food security on a continental scale. With the key to considerable internal migratory movements. There is already an emigration from California to the east following the recurrent fires of recent years. In Arizona, rationing in Colorado has led to the departure of farmers, who are selling farms that have belonged to their families for several generations. Today, mobility is a luxury that the most vulnerable communities do not necessarily have. But there will come a time when it will only be about survival.
From the study of tree rings, a NASA research team led by Ben Cook extrapolated scenarios of drought cycles. In its publication in Science Advances in 2015, she maps the likelihood of desertification in North America if greenhouse gas emissions are not reduced. The conclusions are clear: in 2095, an area stretching from California to Texas, and from Arizona to Kansas, will slide into an arid desert. This transformation will disrupt human occupancy by 2070, as Timothy Kohler, Timothy Lenton, and Marten Scheffer wrote in Proceedings of the National Academy of Sciences (PNAS) in 2020.
The cartographic representations made by the Propublica project on climatic migrations draw the limits of human survival in these now inhospitable areas of a North America defined by environmental inaction. To the point where, according to Abrahm Lustgarten, one of the authors, the migratory flows of those who will flee the drought, on the one hand, and the intense humid heat, on the other, just like the extreme climatic phenomena in the north and south, will end up colliding into as many migratory shocks.
The United States has already experienced population movements of this nature: the dust bowl pushed the first climate refugees in the country’s history onto the roads. And it didn’t go well: Colorado’s then-governor declared martial law in April 1936 and deployed the National Guard to his state’s southern border, believing he no longer had the capacity to admit other refugees. California refused to integrate them, limiting the access of ” okies in certain spaces, while bosses exploited these destitute people from the east—a mood depicted in Steinbeck’s novels. In fact, failing to develop policies to adapt to climate change, as the IPCC called for in its last report, these movements will increase. And with that, the fragmentation of communities, societies, the accentuation of inequalities and the accelerated erosion of the social contract. It would be wrong to believe, there as here, that certain phenomena can be contained by closing borders.