Friday, March 13, 2015

More Evidence California Drought Is Manmade

Researchers at Stanford University published a new paper in the Proceedings of the National Academy of Sciences concluding warming caused by humans is responsible for the conditions responsible the California drought. They put only naturally occurring variations into climate models and were unable to get the exiting conditions. It was only when manmade global warming was included that they were able to get the drought. Manmade emissions have resulted in both periods of warming as well as decreased rainfall. The simultaneous occurrance of these conditions is what is responsible for the condition California is experiencing today. They also found that any future dry period is likely to be accompanied by warm temperatures, meaning this will all likely play out again with greater frequency.

And still, people will insist it is all natural.

Here is an abstract from their paper:
A comparison of historical climate data from California with different climate models has shown the influence of human-driven climate change. Noah Diffenbaugh, Daniel Swain, and Danielle Touma of Stanford University examined the state's records of temperature, rainfall, and drought conditions and evaluated the severity of different periods of warming and drought using the Palmer Hydrological Drought Index and the Palmer Drought Severity Index. They then compared those periods with a range of global climate models. The models that included only naturally occurring variations did not accurately depict California's warm periods, but the models that included anthropogenic warming did. The researchers believe that anthropogenic warming has increased the simultaneous occurrence of periods of both warming and decreased rainfall, which has resulted in an increase in the frequency and severity of droughts across the state.


  1. Dr. Keating, I come to your blog often to keep informed about climate change and the machinations of deniers (especially those in a position of power). I appreciate all your efforts to combat their maddening and seemingly willful blindness to the need for immediate, significant action. I found the following article surprising and makes me want to get more involved in the fight to change our distressing direction. I find it encourages the redoubling of effort, and I wonder what you think. Like you say, the deniers aren't going to change their mind through pointing out why they're wrong. I think the power of this kind of article is that it can fortify the efforts of those who see the problem but feel like it's already just too late.

  2. It is never too late. We might not be able to prevent change, but we can always reduce the amount and keep it from getting any worse.

    There is a noticeable shift in international opinion. Climate change denial is a primarily American phenomenon. That isn't to say it doesn't show up in other countries, but I don't think it has as big of a public following anywhere else as it does here. The Chinese and Indians have been the largest obstacles to agreement on climate change and that was due to economic reasons. Both countries have massive poverty and they are trying to address that issue by building power plants. Both countries, while still wanting to address their economic issues, also recognize they have to address the environmental ones, as well.

    Another cause of dropping emissions is the switch in this country to natural gas-fired power plants versus coal-fired ones. Fracking has a lot to do with that by making natural gas abundant and cheap.

    I am working on a posting on the way people will not accept the science, no matter what. There is a new movie out, Merchants of Doubt, about this very issue. One of the things they talk about is how the more science you show deniers, the more they dig their heels in. From my personal experience, I can attest that this is true.