Filed under: climate change, Hot Earth Dreams, Speculation | Tags: California High Altithermal, climate change, Hot Earth Dreams
I didn’t get to livestyles of posturban peoples this time. That’s the next piece. Indian California was a complex place, with hundreds of peoples and languages and a wide variety of life ways. Modern California’s a massively complicated place, but it’s complicated in very different ways than Indian California was, due its central position in the modern global economy. The High Altithermal will be complicated as well, but in very in different ways than it is now. Here I’m going to write about how California’s jumble of environments shape where (and to some extent how) people live.
Yes, the next 200 years are when everything sucks, because the climate keeps getting warmer. What’s interesting here is how isolated California becomes from the south and east as the desert heats up. The problem here isn’t the desert itself, it’s that people in the present are so busy draining and polluting aquifers. The oases that people used to live around, like the springs that gave Las Vegas its name, will mostly or entirely be gone by the time the High Altithermal kicks in. Worse, the lower Colorado River will be intermittently dry until the dams fail. People who want to cross the deserts will literally be stormchasers, following the rain tracks of major storms to find surface water pools, using these ephemeral waters to make their crossings. Reservoir waters will be a valuable resource, but it’s going to be interesting trekking between them. And they’ll probably be strongly protected by the reservoir owners.
Once the dams fail and the Colorado, the Owens, the Mojave, and other rivers start to flow again, their flows reduced due to the loss of winter snows, then there will be more places for humans in the desert. It will likely take longer than the High Altithermal for groundwater to recharge enough for new springs and oases to develop, so I suspect that High Altithermal settlements in the desert will be along rivers, in canyons, in places where the water doesn’t fail, where crops can be grown, where wildlife gathers and wild plants can reliably be foraged. The rest of the desert will be crossed by travelers heading from water to water, chasing the rains.
The Sierra Nevada, the Cascades, the Tehachapis, the Peninsular Ranges…the Mountains
In Indian times, the western Sierran foothills had the biggest populations. Tribes like the Miwok and the Yokuts headed up to the high Sierras in the summer and down into the Central Valley in the winter, exploiting different areas at different times. Further south, the San Diegan Kumeyaay ranged from the Pacific Ocean to the Colorado River, going to the mountains in between in the summer.
In the 19th century, Sierran herders did the same, sending their sheep (Muir’s “hooved locusts”) up into the mountains every summer. Now, we’ve got parks and national forests in the high country for timber and watersheds, ranches and farms in the foothills, and Big Ag and subdivisions in the Central Valley.
I suspect that future mountains will look more like the Indian past, with people migrating seasonally across unevenly warming mountains. It won’t be easy, especially in the southern mountains, as the drying climate in the next 200 years leads to massive tree die-backs. These will result in fires, resulting in erosion and loss of fertility, especially if it’s too hot and dry for the normal post-fire plants to survive after they sprout. It will take work, like terracing and trenchilas, to increase the number of places that capture the escaping water and sediment, places that recharge the groundwater, places where plants grow. If beavers survive in the Sierras (where they were native and have been reintroduced), that will help groundwater recharge, while excessive grazing (as now) will decrease it.
The northern Sierras and Cascades will get wetter, at least during El Niños. Indeed, the northern rivers, along with the Lake Tahoe/Truckee River/Pyramid Lake system, are a likely place for settlements to persist. Remnants of Reno are more likely to survive than Vegas.
Over the last 1,300 years of the High Altithermal, I suspect that settlements will organize with borders along the mountains that define major watersheds, as people organize to take advantage of resources from the Sierran Crest to the desert and the floor of the Central Valley, following the streams up and down. This is a drastic shift from our current idea of the mountains as forest refuges, but instead of supplying water, timber, and recreation to coastal cities, they’re going to become home to increasing numbers of people.
The Central Valley
For the first 200 years or so, the San Joaquin Valley will just be desert. Water in the area will be limited to surface water for a long time, simply because aquifers have compacted as they’ve been drained, so there’s the state’s already lost something like two Lake Meads worth of groundwater storage capacity in the Valley. When ponds, lakes, and rivers run dry during dry times, there won’t be any springs to fall back on. My guess is that aquifers won’t start reforming and recharging until long after Lake Tulare refills. Even with big, shallow, bulrush-strewn lake to bring the place to life, the western San Joaquin Valley will basically stay desert, even as much of it gets inundated by the sea. The eastern San Joaquin Valley, with Lake Tulare and the foothills, will be much more livable, although still desert.
[UPDATED 2/19] The northern Sacramento Valley will be much wetter. Before 1850 it was largely marshland, flooded in the winter and spring. After the dams, levees, and aqueducts fail, it will become marshland again, but some of these marshes may be suitable agriculture, for growing things like rice. The problem is that, in the fullness of time, the roughly two-thirds of the valley south of Chico will be inundated by the ocean by the end of the High Altithermal. I suspect this loss of land will be common knowledge, and this will likely influence who settles in the southern Sacramento Valley, especially early on.
The Coast Ranges
The Central Valley is ringed by mountains, and the Coast Ranges and their kin run from the Oregon border down continuously to Santa Barbara, and discontinuously south to San Diego.
The tangled northern mountains (that book was called The Klamath Knot for a reason) have the same advantages as the Sierras. These kinds of complex mountains are great refugia for plants, animals and people, the kind of places where people can hide from states or just their enemies. Today though, the area has little pockets of farmland and ranchland here and there all through them. Where the Yurok used to burn prairies and harvest acorns in savannas they maintained, people in the future (including, hopefully, the Yurok) may have a herd of livestock or a farm instead.
The same pattern will continue down the coast, although the southern Coast Ranges will of course be much drier. Further south, big southern canyon systems, such as Malibu and Topanga Creeks, will likely hold permanent water and small settlements on the flats.
If we’re trying to understand how cities fare, I’d suggest two ideas: follow the water, and look at history.
When you follow the water, it’s important to realize that while modern metropolises like Los Angeles and San Francisco depend on imported water, if they’re old enough, the settlements they sprang from depended on local streams. The San Francisco Presidio was built near Lobos Creek (named after Lobos Marinas, or sea lions), which still puts out about one million gallons per year. El Pueblo de Nuestra Señora la Reina de los Ángeles was built near the Los Angeles River, which averages around 150 million gallons per year. While these water sources will decrease as the climate warms, they’re the water future settlements will depend on, and that will determine how many people can live there.
The second problem is farmland. Los Angeles used to have a lot of farms, and as we’ve seen in Detroit, it’s surprisingly possible to rehabilitate suburbs into gardens. San Francisco used to be half sand dune (Golden Gate Park and the Sunset District), with a spine of rock (the city’s hills) and salt marsh along the bay (the Financial District). Given early descriptions, the city’s modern gardens are probably more fertile than the dunes used to be. Before the gold rush, not many people lived there. Now, with water from Lobos Creek, it can only support maybe 10,000-20,000 people, if these new locavores can figure out what to eat.
As for what cities look like after collapse, we know the pattern: decaying cities with small citadels here and there, often protected by walls of repurposed rubble. The classic postapocalyptic look, seen in the archaeology of the Roman Empire, Post-Classic Maya, and many other places. This will happen in the future, but remember that, over 200 years, the settlement has to transition from the classic postapocalyptic survival architecture to a settled farm village. Stuff falls apart, and after awhile, people will have to start building with indigenous materials like wood, grass, bamboo, clay, and mud. Depending on what people invent in the next few decades, there might be some cool materials like mycoconcrete, but absent novel sustainable technology, the farm villages of the future will look a lot like those of the past. In San Francisco, people will cluster around the Presidio and perhaps Mission Dolores (if that spring frees itself from its current plumbing). In Los Angeles, they’ll settle along the Los Angeles and San Gabriel Rivers. Other, smaller cities may develop new villages in their cores, especially when there’s reliable drinking water nearby. Cities in low-lying parts of the Central Valley will be destroyed by floods and buried in the marshes, their main use being mounds of rubble on which people can build above the water.
The ruins of our cities will be great sources for materials, and reprocessing them will be much easier than mining. Unfortunately, without oil or coal, the best fuels for that reprocessing will be things like charcoal and biogas. Since LA had (and has) limited trees, in the later parts of the High Altithermal it may develop a junk and recycling trade, scrapping and shipping materials from the ruins, with only limited remanufacturing going on in the city. Settlements in Northern California may in turn become manufacturing centers, especially if they follow something like the Medieval English model of industries that owned their own forests, managed them sustainably for charcoal production, and imported salvaged materials from the big cities to recycle.
As sea level rises, both San Francisco and Los Angeles will lose ground to the ocean. Some time around 3000 CE, the sea will flood the San Andreas fault rift at Daly City, and San Francisco will become an island. This is actually a serious problem, because the headwaters of Lobos Creek are only about 40 meters above sea level, and San Francisco’s major water source will be lost to the waves. I’m not sure if more springs will develop higher on the hills, whether the island will depend on water imports from the East Bay, or whether it will be largely abandoned. The last is doubtful, simply because San Francisco occupies a strategic point at the entrance of the Bay, and someone, whether a pirate, a warlord, or a governor, will want to occupy it.
Los Angeles will stay a desert city in the south, dependent on runoff from the San Gabriels for their water. Sometimes there will be killing floods, sometimes the rivers will run dry. Whether people survive depends on how well they deal with an environment that’s far more chaotic than we see today.
That’s the golden state of our future. What did I miss?
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