California drought and global warming

C­alifornia has what is called a Mediterranean climate. This means it has two seasons, a wet one and a dry one. The wet one usually starts in November and lasts through the winter and early spring and is characterised by rain and snow in the northern part of the Sierra Nevada Mountains. In the dry season, from mid-spring through October, there is little or no rain.

In recent years the wet season has become shorter and with less rain and snow, while the dry one has lengthened and grown hotter. This reached the point four years ago that the state was officially declared to be in a drought, which has continued to the present and become more extreme.

The dry season is often marked by wildfires, but these have become progressively worse in the course of the drought. This year has had twice the usual number of such fires. One was especially destructive and virtually wiped out a small town, burning nearly 500 homes down to their foundations. Seasoned firefighters said they had never seen anything like it.

Reservoirs are at historic lows, most well below half of the historic average. Scientists also report a groundwater emergency. At the end of the wet season last April, which was hardly wet at all, the snow pack in various parts of the Sierra Nevada, the run-off from which is key to supply water to the state in the summer, was between 16 and 22 percent of normal levels.

Agriculture is big business in the state, concentrated in the Central Valley, which runs between the Sierra Nevada and Costal mountain ranges. More than half of the state’s crop value comes from fruit and nuts, and about a quarter from vegetables. These commodities amount to over 60 percent of total US fruit and nut production and 51 percent of vegetables.

Agricultural losses due to the drought are in the tens of billions of dollars. Some crops have been abandoned. As growers scramble for the depleting water supply, they have turned to pumping up more and more groundwater from ever deeper wells. A result is that the surface ground level in the valley has dropped by over 30 centimetres.

California governor Jerry Brown has declared a state of emergency and called for a 25 percent reduction in water use, a target aimed at individuals and small businesses, not agribusiness, which sucks up 80 percent of California’s water. There have been only small cutbacks imposed on this sector by necessity.

Also let off the hook is Big Oil. An article in the San Francisco Chronicle reports: “A typical Central Valley oil well pulls up nine or 10 barrels of water for every barrel of petroleum that reaches the surface. In addition, companies often flood oil reservoirs with steam to coax out the valley’s thick, viscous crude, which is far heavier than petroleum found in most other states. They pump high-pressure water and chemicals underground to crack rocks in the controversial practice of hydraulic fracturing. They use acid and water to clear up debris that would otherwise clog their oil-producing wells”.

All that leftover contaminated water has to go somewhere. According to the Chronicle, state regulators allowed oil companies to fill 170 aquifers that could be suitable for drinking or irrigation with fracking waste. Companies drilled another 253 wells close to aquifers, and the waste can seep into them.

So not only does Big Oil use up a lot of water, it also poisons the water it uses, which contaminates more water sources.

Will el Niño save the day?

Noah S. Diffenbaugh, associate professor of earth system science at Stanford University, and Christopher B. Field, director of the department of global ecology at the Carnegie Institution for Science, wrote recently in the New York Times:

“As wildfires rage, crops are abandoned, wells run dry and cities work to meet mandatory water cuts, drought-weary Californians are counting on a savior in the tropical ocean: El Niño.

“This warming of the Pacific occurs about every five years, affecting climate around the globe and bringing heavy winter precipitation to parts of California. The state experienced two of its wettest years during two of the strongest El Niños, in 1982-83 and 1997-98.

“Now climatologists have confirmed that a powerful El Niño is building, and forecasts suggest a high likelihood that El Niño conditions will persist through the next several months. So we in California expect a rainy winter.

“But before everyone gets too excited, it is important to understand this: Two physical realities virtually ensure that California will still face drought, regardless how this El Niño unfolds.

“The first is that California has missed at least a year’s worth of precipitation, meaning that it would take an extraordinarily wet rainy season to single-handedly break the drought. Even if that happened, we would most likely suffer from too much water too fast, as occurred in the early 1980s and late 1990s, when El Niño delivered more rainfall than aquifers could absorb and reservoirs could store.

“The second is that California is facing a new climate reality, in which extreme drought is more likely … Our research has shown that global warming has doubled the odds of the warm, dry conditions that are intensifying and prolonging this drought, which now holds records not only for lowest precipitation, but also for the lowest spring snow pack in the Sierra Nevada in at least 500 years.”

The study indicated that present drought conditions are a once-in-1,000 years event. It boggles the imagination to believe that this rare event is a random coincidence with global warming.

The scientists added, “We are not arguing that the drought has been caused by climate change alone, or that all weather disasters have a link to climate change … As with the California drought, climate change is an important thumb on the scale, increasing the odds of particular extremes in specific places [worldwide]”.

To understand the impact all this is having and will have in the future on California’s economy, it is useful to look at the state’s water use structure. The importance of the snow pack in the Sierra Nevada is indicated by the fact that its run-off as it melts fills reservoirs that provide a third of all the drinking water for the state, as well as water to fight fires and generate electricity.

The Central Valley is naturally a desert. It has become fertile only through massive irrigation from water pumped from the rivers that depend on the snow pack. The snow accumulates well north of the Central Valley. Water pumped from the rivers that depend on the snowpack not only irrigates the farms in the valley, but is also an important source for Los Angeles and all of southern California.

The clear present and future danger resulting from the disruption of this water use system is obvious. To carry through the large-scale revamping necessary to cope with this disaster runs directly into the obstacle of the big capitalist firms involved, which are driven by the iron necessity of maximising their profits, no matter what the costs to society at large.

As is the case with all the problems caused by the burning of fossil fuels, no long-term solutions are available under the capitalist system. Partial reforms can be fought for and won, but such struggles will pit the working people against powerful capitalist interests, which will open the door to understanding that the system itself must be changed – along the lines of the slogan that has become popular in the environmental movement: system change, not climate change.