Significant and widespread drought conditions continue in California which experienced its warmest and third driest winter on record. Drought is expected to persist or intensify in California, Nevada, most of interior Oregon and Utah, Arizona, New Mexico, southeast Colorado, western Oklahoma, and most of west Texas because of below-average rain or snow this winter and the onset of the dry season in April.
Nearly all of California has been experiencing record high temperatures on a daily basis including the establishment of new all-time January record high temperatures.
As Daniel Swain has noted, “2013 was the driest on record in California’s 119 year formal record, and likely the driest since at least the Gold Rush era.”
In addition to this impressive stretch of record-breaking warmth, the observed atmospheric flow pattern over California has been downright bizarre! Weak disturbances have been propagating westward or northwestward over the state around the south side of the highly persistent ridge, bringing periodic mid and high-level cloudiness and occasional offshore winds. This flow pattern is completely reversed from its normal orientation (weather systems in winter typically move eastward over California).
Just to give some indication of how strange this pattern really is: the moisture source for the observed cloudiness across parts of California is the subtropical East Pacific Ocean southwest of Baja California (rather than the Gulf of Alaska).
Scientists have long predicted that climate change would bring on ever-worsening droughts, especially in semi-arid regions like the U.S. Southwest. As climatologist James Hansen, NASA Scientist Who Raised Climate Change alarm and who co-authored one of the earliest studies on this subject back in 1990 – “Increasingly intense droughts in California, all of the Southwest, and even into the Midwest have everything to do with human-made climate change.”
Why does it matter if climate change is playing a role in the Western drought? As one top researcher on the climate-drought link confirmed – “The U.S. may never again return to the relatively wet conditions experienced from 1977 to 1999.” If his and other projections are correct, then there may be no greater tasks facing humanity than 1) working to slash carbon pollution and avoid the worst climate impact scenarios and 2) figuring out how to feed nine billion people by mid-century in a Dust-Bowl-ifying world.
Climate scientists and political scientists often confuse the public and the media by focusing on the narrow question, “Did climate change cause the drought” — that is, did it reduce precipitation?
Remarkably, climate scientists specifically predicted a decade ago that Arctic ice loss would bring on worse droughts in the West, especially California. As it turns out, Arctic ice loss has been much faster than the researchers — and indeed all climate modelers — expected.
California is now in the death–grip of a brutal, record-breaking drought, driven by the very change in the jet stream that scientists had anticipated. Is this just an amazing coincidence — or were the scientists right? And what would that mean for the future?
In general, most Leading Climate Change scientists say that is the wrong question — severe drought is much more than just a reduction in precipitation. After a political scientist labeled his mainstream views “zombie science,” John Holdren, Obama’s Science Czar, explained in an extended debunking how climate change worsens Western droughts even if it doesn’t reduce precipitation (see here).
Scientists a decade ago not only predicted the loss of Arctic ice would dry out California, they also precisely predicted the specific, unprecedented change in the jet stream that has in fact caused the unprecedented nature of the California drought. Study co-author, Prof. Lisa Sloan – “I think the actual situation in the next few decades could be even more dire that our study suggested.”
Back in 2004, Sloan, professor of Earth & Planetary Sciences: UC Santa Cruz, and her graduate student Jacob Sewall published, “Disappearing Arctic sea ice reduces available water in the American west.” They used powerful computers “to simulate the effects of reduced Arctic sea ice,” and “their most striking finding was a significant reduction in rain and snowfall in the American West.”
“Where the sea ice is reduced, heat transfer from the ocean warms the atmosphere, resulting in a rising column of relatively warm air,” Sewall said. “The shift in storm tracks over North America was linked to the formation of these columns of warmer air over areas of reduced sea ice.” In January, Sewall wrote me that “both the pattern and even the magnitude of the anomaly looks very similar to what the models predicted in the 2005 study.” (see Fig. 3a [below]).
Here is what Sewall’s model predicted in his 2005 paper:“Geopotential Height” is the height above mean sea level for a given pressure level. The “500 mb level is often referred to as the steering level as most weather systems and precipitation follow the winds at this level,” which is around 18,000 feet.
Now here is what the 500 mb geopotential height anomaly looked like over the last year, via NOAA:
That is either a highly accurate prediction or one heck of a coincidence.
The San Jose Mercury News explained that “meteorologists have fixed their attention on the scientific phenomenon they say is to blame for the emerging drought: a vast zone of high pressure in the atmosphere off the West Coast, nearly four miles high and 2,000 miles long, so stubborn that one researcher has dubbed it the Ridiculously Resilient Ridge. This high pressure ridge has been acting “like a brick wall” and forcing the jet stream along a much more northerly track, “blocking Pacific winter storms from coming ashore in California, deflecting them up into Alaska and British Columbia, even delivering rain and cold weather to the East Coast.
Last year, I contacted Sloan to ask her if she thought there was a connection between the staggering loss of Arctic sea ice in recent years and the brutal drought gripping the West, as her research predicted. She wrote, “Yes, sadly, I think we were correct in our findings, and it will only be worse with Arctic sea ice diminishing quickly.”
Yes, in this case I hate that we (Sewall & Sloan) might be correct. And in fact, I think the actual situation in the next few decades could be even more dire that our study suggested. Why do I say that? (1) we did not include changes in greenhouse gases other than CO2; (2) maybe we should have melted more sea ice and see what happens; (3) these atmospheric and precipitation estimates do not include changes in land use, in the US and elsewhere. Changing crops, or urban sprawl increases, or melting Greenland and Northern Hemisphere glaciers will surely have an impact on precipitation patterns.
All this isn’t “proof” that human caused climate change helped shift and reduce precipitation in California during its record-setting drought. But a prediction this accurate can’t be ignored, either, especially because of its possible implications for the future.
Emerging evidence — documented by Senior Weather Channel meteorologist Stu Ostro and others — that “global warming is increasing the atmosphere’s thickness, leading to stronger and more persistent ridges of high pressure, which in turn are a key to temperature, rainfall, and snowfall extremes and topsy-turvy weather patterns like we’ve had in recent years.”
That’s why it was so puzzling that NOAA’s Martin Hoerling was quoted in the NY Times Thursday saying “to state the obvious, this drought has occurred principally due to a lack of rains, not principally due to warmer temperatures.” He ended by saying, “It is quite clear that the scientific evidence does not support an argument that this current California drought is appreciably, if at all, linked to human-induced climate change.”
Except that it is not quite clear there is no connection to climate change — as we’ve seen. Michael Mann, one of the country’s leading climatologists:
There is credible peer-reviewed scientific work by leading climate scientists, published more than a decade ago, that hypothesized that precisely this sort of blocking pattern would become more frequent with disappearing Arctic sea ice. Moreover, Arctic sea ice has declined precipitously in the intervening decade. So it seems quite clear that there is a potential connection, in a statistical sense, between “Human Caused Global Warming,” declining Arctic sea ice, and the anomalous blocking pattern this winter that has added to other factors we know are tied to “human-caused climate change” (warmer temperatures and increased soil evaporation, and decreased winter snowpack and freshwater runoff) to produce the unprecedented drought this year in California.
To claim that it is “quite clear” there is no connection at all turns the burden of scientific evidence completely on its head. Such a statement defies logic.
Climatologist and California water expert Dr. Peter H. Gleick:
Dr. Hoerling is answering the wrong question and his wording is conflating different research findings. In addition, his wording is confusing.
“Occurred principally”?? This is NOT the same thing as saying there is “no link between warmer temperatures and the current drought.” But that’s seems to be what he is implying.
Yes, the drought is principally due to lack of rain, not “principally” due to warmer temperatures. But note this is NOT saying that higher temperatures aren’t playing a role. To adopt his wording but saying the opposite: “To state the obvious, higher temperatures already occurring are worsening the impacts of the ongoing drought no matter its cause.”
His second sentence is also correct but perverse and incomplete. In particular, the word “linked” is misleading (does he mean causality or influence; if the former, he is correct; if the latter, he is incorrect).
Gleick has posted a good analysis of the confusion and conflation going on. He notes “the most definitive and well-understood effect (higher temperatures) have decreased current water availability” and shares this chart:
“The extra heat from the increase in heat trapping gases in the atmosphere over six months is equivalent to running a small microwave oven at full power for about half an hour over every square foot of the land under the drought,” climatologist Kevin Trenberth explained to me via email. “No wonder wild fires have increased! So climate change undoubtedly affects the intensity and duration of drought, and it has consequences.”
Holdrem wrote: “In my recent comments about observed and projected increases in drought in the American West, I mentioned four relatively well understood mechanisms by which climate change can play a role in drought. (I have always been careful to note that, scientifically, we cannot say that climate change caused a particular drought, but only that it is expected to increase the frequency, intensity, and duration of drought in some regions ― and that such changes are being observed.)”
These four mechanisms are:
- In a warming world, a larger fraction of total precipitation falls in downpours, which means a larger fraction is lost to storm runoff (as opposed to being absorbed in soil).
- In mountain regions that are warming, as most are, a larger fraction of precipitation falls as rain rather than as snow, which means lower stream flows in spring and summer.
- What snowpack there is melts earlier in a warming world, further reducing flows later in the year.
- Where temperatures are higher, losses of water from soil and reservoirs due to evaporation are likewise higher than they would otherwise be.
Holdren reviews the scientific literature on those statements in his reply, noting “the second, third, and fourth mechanisms reflect elementary physics and are hardly subject to dispute.”
Wildfires: California experienced truly ferocious wildfires last year. If things remain this dry, 2014’s wildfire season could be especially nasty, too. An area of “significant” fire potential is predicted to grow bigger and bigger throughout California over the coming months, according to the National Interagency Fire Center. By early summer, it looks like about half the state might be at above-average risk for fires, not a great thing for the camping industry or anybody with homes in dry zones:
Food prices: Roughly 50 percent of America’s fruits and vegetables come from California, but the fecund Central Valley lately has been more suitable for a tumbleweed preserve. Farmers are letting their fields go fallow and ranchers are thinning herds rather than pay for expensive feed, measures that wind up slamming consumers. In the past year, the average price for a hamburger has risen by 20 percent, and the costs of milk, cheese, and other dairy products will also be vulnerable to hikes, according to an analyst interviewed by the Sacramento Bee.
The real worry, however, is what will happen if this drought doesn’t go away soon, writes the Bee:
It could get a lot worse. Experts say most farmers should be able to keep going this season, but many of them won’t be able to survive another season of drought.
“The general mood is, ‘We’ll get through this year, but who knows about next year?'” said Erik Balling of Green Leaf Ag, a Coalinga irrigation-services company. “If there’s another severe drought, the face of farming is going to change.”
Water rationing: With reservoirs turning into dust bowls, California has made the unprecedented decision to not supply water to many urban and agricultural agencies this spring. Other federal agencies that channel water to the state are also cutting back in huge ways. If the drought persists, it’s hard to imagine a future California in which people are not constantly scrambling to preserve the precious little water left.
Many are still asking is current global warming natural or human caused? The idea that global warming is natural is not an absurd question. In the natural cycle, global warming is natural. The better question is, ‘is current Global Warming Natural Cycle?
For now I remain a skeptic, but I’ll be keeping an eye on the forecast for any signs of significant drought relief, but at this late date, it’s doubtful any relief is in sight. In the meantime, I strongly encourage everyone in California to be mindful of their water usage in the midst of these increasingly “severe drought conditions” or “Water Grab,” and to take active conservation steps in advance of what promises to be a challenging summer and fall ahead.