Friday, April 24, 2015

Dealing with drought

Lately, some alarming messages have been spread via the media about drought in California - some of them are a bit misleading (e.g., that CA has only one year's worth of water left - the situation is dire, but that's a hyperbolic statement of the reality).  There are those who will lay the blame on global climate change.  This is also not an appropriate position, since there always has been a danger of drought in the semiarid and arid regions of the US, and no guarantee can be made that what we've observed in the historical record is as bad a drought as natural variability can generate.  Climate change may be making the situation worse, but it's not the whole challenge.

A major part of the problem for CA and, indeed, for much of the western third of the USA (east of the coastal mountain ranges) is that drought always has been a frequent visitor - from the Great Plains westward to those coastal mountain ranges.  The notion that the expanding population centers from the continental divide westward are living on borrowed time is not a new one.  I recommend reading "Cadillac Desert" to learn some of the history of the "water wars" in the west.  Dividing up the scarce water resources among all the competitors has always been a challenge even during non-drought years;  increasing populations demand more of everything.  Making choices is not necessarily easy.  Drought magnifies the urgency and the seriousness of the consequences for any set of choices.  Large population centers, like Los Angeles, El Paso, Denver, Las Vegas, Phoenix, Tucson, etc., are reaching out over increasing distances to find new water to support additional growth. 

A lot of agriculture west of the Mississippi River uses irrigation to grow crops that in most years would not be possible depending only on natural rainfall.  On the plains, much of this water for irrigation is "fossil water" in underground aquifers that represent finite resources.  When (not if!) those aquifers dry up, that agriculture can't be sustained.  Decreasing fresh water sources in the west leave agricultural (and industrial) uses competing with human water needs.

What's worse is that water is being squandered stupidly ... for example, building grassy golf courses in the desert is an ecological nightmare.  Where I used to live in CO, the neighborhood association discouraged xeriscaping, and encouraged homeowners to maintain Kentucky bluegrass lawns that required heavy watering at least every other day in that semiarid climate.  Wasting fresh water in such stupid ways has potentially harmful consequences even in non-drought times, but when drought is ongoing, such waste can be criminal.

Some simple calculations show that the cost in terms of energy to pipe in water from water-rich areas, mostly east of the continental divide, is quite high.  Using that much energy to import water - generally uphill - creates problems in its own right, and will make that water very expensive.  The real problem here isn't the current drought.  It's the growth of unsustainable populations in regions that inevitably are going to experience serious droughts that constitutes the real problem.  Anthropogenic global climate change may be enhancing that concern, but it's always been there.   Whenever local sources of water become inadequate for the population centers, those centers have populations that have become unsustainable.  Even before anthropogenic climate change became a topic for discussion, there were ongoing battles for fresh water resources.  Everyone feels their personal concerns take priority, but politicians who make the laws governing water rights can be influenced by the rich to favor the claims of the rich to that fresh water.

Drought has been ongoing for several years in the western half of Oklahoma and the Texas Panhandle, to the extent that an old bogeyman is making an unwelcome appearance:  cloud seeding.  It's not widely understood that the conditions of a real drought - an absence of rainclouds - make seeding completely useless in mitigating that drought.  Even in cases when rainclouds are present, the actual contribution of cloud seeding to net rainfall has never been shown to be effective in any carefully-done statistical trials.   I have a more comprehensive discussion of weather modification, but the substance of the science is that weather modification to enhance rain has never passed rigorous statistical tests of its effectiveness.  The weather modification companies who sell their "services" for the purpose of drought mitigation haven't a scientific leg to stand on, and yet are profiting from the misery of those suffering from drought.  Those companies may well honestly believe in what they're doing, but the opinion of weather modification activities from the science of meteorology is pretty much dubious.

In OK, we now have vast quantities of waste water from fracking being pumped underground, which not only consumes that water, but has the potential to contaminate the underground water (to say nothing of causing earthquakes in certain areas).  As I said, drought makes many "minor" concerns morph into serious concerns.

Dealing with drought is never easy ... as fresh water availability declines, there will be winners ... and losers.  Who decides who wins and who loses?  On what basis?  The simple fact is we can't survive without adequate fresh water, and as the resource declines, it's going to get ugly.  The sooner we face the unpleasant realities of drought and its consequences, the better.  Sticking your head in the sand won't solve anything.  Solutions won't come easily and it's impossible to use the diminishing resource to satisfy the needs of the increasing demand.