Many people will know that parts of the western USA are in the throes of a serious drought. The dry conditions over parts of western USA have been mentioned here on HotWhopper a few times (eg here and here and here) and it's been all over the internet.
Finally Anthony Watts has written about it (archived here). This is after the Governor of California has declared a drought emergency - while a wildfire raged in southern California during the heart of winter.
Perhaps Anthony felt he had to pre-empt suggestions that the record drought was associated with global warming, now that the news of it has spread far and wide. He wrote:
And the cause of this? Certainly not “global warming” though I’m sure the activist idiots will use every trick in the book to try to create a linkage. The cause is a the Pacific Decadal Oscillation and a weak to neutral and persistent La Niña pattern that some are calling “La Nada”.
I don't know how Anthony is so sure of himself. He doesn't cite any research on the subject. Here is some relevant research which he could have cited, from the IPCC AR5 WG1 report (my bold italics):
Recent long-term droughts in western North America cannot definitively be shown to lie outside the very large envelope of natural precipitation variability in this region (Cayan et al., 2010; Seager et al., 2010), particularly given new evidence of the history of high-magnitude natural drought and pluvial episodes suggested by palaeoclimatic reconstructions (see Chapter 5). Low-frequency tropical ocean temperature anomalies in all ocean basins appear to force circulation changes that promote regional drought (Hoerling and Kumar, 2003; Seager et al., 2005; Dai, 2011). Uniform increases in SST are not particularly effective in this regard (Schubert et al., 2009; Hoerling et al., 2012). Therefore, the reliable separation of natural variability and forced climate change will require simulations that accurately reproduce changes in largescale SST gradients at all time scales.
So at present, the drought may or may not be exacerbated or precipitated by global warming, but that cannot be definitively demonstrated at present. Anthony is wrong to be so sure of himself. In any case, all weather these days is affected by global warming. If there wasn't this amount of energy in the system, weather would be different to what it is. Whatever the weather, it's against the background of the warmer world.
For example, there is this research I've mentioned before from Schwalm et al (2012) in Nature Geoscience:
|Figure 4b Normalized CMIP5 summer precipitation from 1900 to 2100, ﬁve-year mean. Horizontal line denotes the turn of the century drought severity. Red and blue shading shows dryness more or less severe, respectively, than the turn of the century drought. Arrows indicate the turn of the century drought. Source: Schwalm12|
A bit too late...
Anthony has a lot of cheek, too. He wrote (my bold italics):
Yesterday, Governor Brown declared a drought emergency, which is probably a bit too late.
I don't know what Anthony meant by "a bit too late". But what struck me was that Anthony's article could equally well be described as "a bit too late". AFAIK this is the first time he's mentioned it at WUWT. And remember when last year he replied to a tweet by Peter Gleick about the California drought with: "Big F*&ing Deal" - "it's happened before" - meaning "so what!".
Anyway, he's finally changing his tune and acknowledging that it is indeed a "Big F*&ing Deal". It's a bit late though!
California has been in drought more often than not since the early 1980s. Here is a chart from Jeff Master's blog at wunderground.com.
|Source: NOAA via wunderground.com|
What to do?
Governor Brown is urging people to reduce water consumption by (another?) 20%. (I believe residential water consumption per capita has dropped a lot in California, following successive public awareness campaigns and imposition of water restrictions. I wasn't able to find any specific data - if someone knows of any maybe they can point to it).
In researching for this article I came across an interesting paper by Ryan Cahill and Jay Lund, which was published last year, with the title: Residential Water Conservation in Australia and California. Below is a table from that paper using data for 2010 - I've highlighted Australia, Portland Oregon and Californian cities for comparison:
The very low residential consumption in Melbourne and Brisbane in particular reflects the severe droughts experienced there at the time, with water storages extremely low, strong water restrictions plus wide public awareness. Remember the table is for 2010. It is likely/possible that per capita consumption in the USA has dropped since then, but I don't know the numbers.
Cahill, Ryan, and Jay Lund. "Residential water conservation in Australia and California." Journal of Water Resources Planning and Management 139, no. 1 (2012): 117-121.
Schwalm, Christopher R., Christopher A. Williams, Kevin Schaefer, Dennis Baldocchi, T. Andrew Black, Allen H. Goldstein, Beverly E. Law, Walter C. Oechel, and Russel L. Scott. "Reduction in carbon uptake during turn of the century drought in western North America." Nature Geoscience 5, no. 8 (2012): 551-556.
From the WUWT comments
Here are a few comments to Anthony's article (archived here).
Bill Jamison says, wrongly, that "models have been predicting an El Nino for a while now". They haven''t - at least the POAMA models at BoM haven't been. They've been reporting ENSO neutral for quite some time:
January 18, 2014 at 2:51 pm
“If the Nino 3.4 model ensemble is to be believed, then California will likely see a strong precipitation rebound in 2014/2015.”
Those models have been predicting an El Nino for a while now. They have no skill unfortunately. We need a pattern change and the high pressure ridge to break down but I don’t see that happening any time soon. There just isn’t enough amplitude right now to break it down.
While wazsah points out:
January 18, 2014 at 3:12 pm
This month the SOI index has moved positive – towards La Nina – both 30day and 90 day averages are trending more positive.
So just now any talk of El Nino is a touch creative.
(From BoM: Sustained positive values of the SOI above +8 may indicate a La Niña event, while sustained negative values below −8 may indicate an El Niño event. Values of between about +8 and −8 generally indicate neutral conditions. There was a recent HotWhopper article on ENSO.)
Gary Pearse says the opposite of what deniers in Australia typically advocate and says (excerpt):
January 18, 2014 at 2:51 pm
Desalination would seem to be good investment if drought is periodic. Personal ones from $1000 to $5000 producing 1 quart to 7 gallons an hour (yachtsmen know these things).
Pamela Gray says:
January 18, 2014 at 9:10 pm
ENSO neutral is a mistaken label in my opinion. I have said it before (and may have coined the label) that La Nada/El Nado may be where all the action is and should be studied as much if not more than El Niño/La Nina is.
And finally, a bit of global warming humour from down under, where we're having another hot and fiery summer. Green Sand says:
January 18, 2014 at 3:57 pm
Overheard on OZ TV:-
Hot? Jeez, chickens are laying omelets!