Filed under: Altithermal, climate change, Hot Earth Dreams | Tags: California High Altithermal, climate change, future, Hot Earth Dreams
Over the last few weeks, I’ve been reading articles (such as this one) about how anomalously warm Alaska and other parts of the Arctic were this winter. Someone even said that if California had warmed half as much as the Arctic did, we’d be in trouble.
Well, we did warm about half as much. By my calculations, San Diego was 9°F/5°C warmer than average for the month of February. This turned what is normally our wettest month into a dry month, with tumbleweeds sprouting in February instead of June, and flowers blooming months early. The heat squelched our El Niño rains, with persistent high pressure forcing the rains north to flood northern California and Oregon. Since I’m not a climatologist, I can’t say authoritatively that this is the new normal, but given the fossil record of rain forests in Oregon and the models of a hot dry So Cal, I’ll go out on a little bitty limb and say it sure could be. But I’m not sure whether we know that we’re in trouble yet.
Still, some rain did get through, so my wife and I took a three day weekend to go up to Death Valley and see the tail end of the “superbloom,” and all I got was this lousy blog idea. Actually, I had fun and got a lot of cool pictures of individual flowers and landscapes as well, but the massive fields of flowers have faded away.
As I drove that narrow ribbon of highway through the valley of death, across the slopes of alluvial fans and the toes of bajadas , looking out at saline dry lakes, I started musing about whether this was the future for Southern California: oppressively hot (actually, it was only 99°F/38°C, so not at all bad) and barren, with life confined to oases. Perhaps there’s an element of truth there?
One truth that Death Valley makes clear is that water is life, and the rest is details. The little flecks of civilization cling to pockets of fresh water: Furnace Springs, Stovepipe Wells, with tiny ribbons of road between them. The superbloom of annual flowers was another version of this response, of millions of plants taking advantage of a bit extra rainwater in the soil to pull it out of the soil, build it into their tissues, live fast, die young, and leave some beautiful seeds. The valley’s sparse shrubs have a lot of space between them, just so they can harvest enough water. They’re dormant through most of the year, growing only when there’s water available. There are also little, often salty, oases, like Salt Creek, a little trickle about twice the salinity of seawater that has it’s own subspecies of inch-long pupfish that lives nowhere else.
So far as I know, those fish live in Pleistocene groundwater that’s bubbled up through the salt. That’s true for all the permanent water in the area: the springs are remnants of the last ice age, when Death Valley was covered by lakes. There’s a fair amount of water under the desert, but those aquifers are not being replenished. The reason the springs they support have lasted 12,000 years and more is that they’re small in comparison to the size of their parent aquifers. As you might imagine, everyone from ranchers and farmers to the city of Las Vegas has been trying to suck that groundwater out, but unfortunately it wouldn’t quench their thirst, only prolong their short struggle with the desert.
Even the landscape is shaped by water. Those alluvial fans, which coalesced into bajadas, are the remnants of rare flash floods scouring everything from dust to boulders out of the high mountains and dumping them on the desert below. There’s little or no vegetation on the slopes, no loamy soil to let the rain soak in, percolate into groundwater, and come out in springs. Instead rainstorms scour, causing mudslides and flash flood that pull dirt, rock, and debris with them. Ultimately, there’s no route for water to get to the sea out in the Mojave, so whatever is left of the floodwater pools in the dry lake beds and evaporates, leaving the salts behind. That’s what happens with rare rains and scanty vegetation: the mountains erode and form alluvial fans at their base.
Closer to the coast, even scrubby chaparral vegetation is pretty good at catching rain, letting it soak into the ground, releasing it into springs. Mudslide erosion happens after fires, or where people got stupid about clearing slopes, and the rain hits bare soil and rock. Still, as southern California gets hotter, the vegetation will die back, the bare slopes will increase, and the rains will cause more erosion. Keep this up long enough, and mountains in California that aren’t currently in the desert will show their rocks as they lose their plants, their leaf litter, their organic soils. Steep gullies and canyons will shed flash floods, alluvial fans will form at their mouths, and the shape of the land will change, even if the mostly dry streams occasionally drain to the sea. For many millennia after that, even after the rains return and the slopes are revegetated, the remnants of alluvial fans and bajadas will tell a story of a desert past.
Before groundwater extraction and silliness like the golf course at Furnace Creek (and a swimming pool, too! In Death Valley! Like this is a sane form of tourism!), the desert Indians mostly lived by springs, venturing away to hunt, gather, and trade, but bound by water. Indeed, their ancestors had first settled the area when it was covered by lakes, adapting, then adapting, then adapting again as the climate warmed, the Pleistocene megafauna died out, the lakes went away, and the desert grew hotter and drier. They’re still there, even in a little Indian village in Death Valley.
But their key lesson is about the critical importance of oases, something I’ve brought up before. One of the most permanently damaging things our we will do in the next few decades is to suck the desert aquifers, try to keep Las Vegas and places like it going, rather than letting them dry up and blow away like Rhyolite, a mining town on the edge of Death Valley that lasted only about 12 years, but held 11,000 people at its population peak. Without water from the last ice age, there’s no place for even small bands of people (Shoshone, Anglo, Latino, or other), to take refuge during the furnace summers of the High Altithermal. Without water, the deserts are mostly uninhabitable. Uninhabitable, that is, except for when the El Niño storms break through, put a brief flush of green on the landscape, and give humans and animals a chance to sneak in from the edges, maybe cross to greener pastures elsewhere if they’re fast enough and daring enough to cross before it dries out, and willing to wait years on the other side to return. Without water, with increasing heat, the deserts will spread.
Oh, and a final note: we stayed in Lone Pine, a hundred miles away from Death Valley in the Owens Valley. The Owens River is running, but it would be a creek anywhere else in the world. There’s a sheen of water on parts of Owens Lake, but there were also blowing dust storms while we were there where it’s still dry and saline (the water’s there to try to keep the dust down, since it’s fairly toxic). Seeing it now, I doubt Owens Lake will refill any time soon, even if LA stops sucking water out of the Owens to feed its lawns and pools. There’s less snow melt to feed it, and more evaporation to dry the lake. The town of Lone Pine, north of Lake Owens, has a nice hotel and some decent restaurants. It’s also anomalously warm, as a retired search and rescue worker told me (his wife runs the Alabama Hills cafe). A decade or two ago, Lone Pine would have been freezing at night in March, perhaps with snow on the ground. Now people are out in tee-shirts and the late spring wildflowers are blooming. There’s just a bit of snow on the High Sierras to the west. It’s at least ten degrees warmer here too, just like in the Arctic.
Welcome to the future. It’s breaking out all over.
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