It is almost impossible to read a media story any more about severe weather events without seeing some blurb about such and such event being the result of manmade climate change. I hear writers all the time saying that it is exhausting to run the gauntlet of major media fact checkers, so why do they all get a pass on these weather statements? Even the IPCC, which we skeptics think is exaggerating manmade climate change effects, refused to link current severe weather events with manmade CO2.
The California drought brings yet another tired example of this. I think pretty much everyone in the media has operated from the assumption that the current CA drought is 1. unprecedented and 2. man-made. The problem is that neither are true. Skeptics have been saying this for months, pointing to 100-year California drought data and pointing to at 2-3 other events in the pre-manmade-CO2 era that were at least as severed. But now the NOAA has come forward and said roughly the same thing:
Natural weather patterns, not man-made global warming, are causing the historic drought parching California, says a study out Monday from federal scientists.
"It's important to note that California's drought, while extreme, is not an uncommon occurrence for the state," said Richard Seager, the report's lead author and professor with Columbia University's Lamont Doherty Earth Observatory. The report was sponsored by the National Oceanic and Atmospheric Administration. The report did not appear in a peer-reviewed journal but was reviewed by other NOAA scientists.
"In fact, multiyear droughts appear regularly in the state's climate record, and it's a safe bet that a similar event will happen again," he said.
The persistent weather pattern over the past several years has featured a warm, dry ridge of high pressure over the eastern north Pacific Ocean and western North America. Such high-pressure ridges prevent clouds from forming and precipitation from falling.
The study notes that this ridge — which has resulted in decreased rain and snowfall since 2011 — is almost opposite to what computer models predict would result from human-caused climate change.
There is an argument to be made that this drought was made worse by the fact that the low precipitation was mated with higher-than average temperatures that might be partially attributable to man-made climate change. One can see this in the Palmer drought severity index, which looks at more factors than just precipitation. While the last 3 years was not the lowest for rainfall in CA over the last 100, I believe the Palmer index was the lowest for the last 3 years of any period in the last 100+ years. The report did not address this warming or attempt to attribute some portion of it to man, but it is worth noting that temperatures this year in CA were, like the drought, not unprecedented, particularly in rural areas (urban areas are going to be warmer than 50 years ago due to increasing urban heat island effect, which is certainly manmade but has nothing to do with CO2.)
Update: By the way, note the article is careful to give several paragraphs after this bit to opponents who disagree with the findings. Perfectly fine. But note that this is the courtesy that is increasingly denied to skeptics when the roles are reversed. Maybe I should emulate climate alarmists and be shouting "false balance! the science is settled!"