Much of the hysteria related to global warming comes from the predictions of computer models. As I mentioned previously, even the father of global warming admits that the currently-available data are not sufficient evidence for the hysteria surrounding global warming, but if you look at the “physics” (i.e., the computer programs that attempt to model climate physics), you see that more carbon dioxide means rising global temperatures. Indeed, much of the famous IPCC report that concludes “it is extremely likely that human activities have exerted a substantial net warming influence on climate since 1750” is based on global climate models. That report further states:
Climate models are based on well-established physical principles and have been demonstrated to reproduce observed features of recent climate and past climate changes.
The problem is, when you test the models’ predictions, they generally fail. As I have already noted, model predictions regarding increasing global temperatures have failed spectacularly, and a lot of that has to do with how poorly those models take into account the negative feedback mechanisms that are a part of earth’s design.
Well, the global climate models have been tested again, and once again, they have failed miserably.
In April of 2007, the journal Science published a paper that made some very scary predictions regarding Southwestern North America:
Here we show that there is a broad consensus amongst climate models that this region will dry significantly in the 21st century and that the transition to a more arid climate should already be underway.1
The paper went on to say that the we should expect a return to the “Dust Bowl” days for much of the southwest. Not surprisingly, the data show that the global climate models couldn’t be more wrong.
A collaboration between the U.S. Geological Survey and the University of Delaware has actually looked through the records of precipitation in the southwestern United States from 1951 through 2006. Here is what the researchers found:
Since the mid-1970s, El Niño events have been more frequent, and this has resulted in increased precipitation in the southwestern United States, particularly during the cool season. The increased precipitation is associated with a decrease in the number of dry days and a decrease in dry event length.2
So the data tell us that the southwest has experienced an increase in precipitation as well as a decrease in the number of dry days since the mid-1970s. The authors find that their analysis is consistent with other analyses. They say:
Our results are consistent with analyses of trends in discharge for sites in the southwestern United States, an increased frequency in El Niño events, and positive trends in precipitation in the southwestern United States.2
So in the end, far from being on its way to a “Dust Bowl” climatology, the southwestern United States has actually become wetter over the past 35 years or so. This, of course, is precisely opposite of what has been predicted by a consensus of global climate models.
At some point, people will understand that we shouldn’t do science based on the predictions of computer models that time and time again fail when they are compared to the data. Until that time, however, expect to hear more nonsense about global warming.
2. Gregory J. McCabe, David R. Legates, and Harry F. Lins, “Variability and trends in dry day frequency and dry event length in the southwestern United States,” Journal of Geophysical Research 115:D07108, 2010 Available online
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