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Monday, August 26, 2013

Bombshell*: Bob Tisdale accepts a climate science paper in BAMS

Sou | 11:29 PM Go to the first of 4 comments. Add a comment

Bob Tisdale has a look at Peterson et al (2013) Monitoring and Understanding Changes in Heat Waves, Cold Waves, Floods, and Droughts in the United States: State of Knowledge from the June issue of BAMS.  He decides that because there were heat waves and droughts in the USA in the 1930s and 1950s, the world isn't getting an increase in extreme weather events.  Flawed logic?  Yes, indeed.

Bob highlights some sentences from the conclusion, which is set out below (my para breaks):

Four key types of climate extremes (i.e., heat waves, cold waves, floods, and droughts) were assessed.
The data indicate that over the last several decades heat waves are generally increasing, while cold waves are decreasing. While this is in keeping with expectations in a warming climate, decadal variations in the number of U.S. heat and cold waves do not correlate that closely with the warming observed over the United States. The drought years of the 1930s had the most heat waves, while the 1980s had the highest number of cold waves.
River floods do not show uniform changes across the country; flood magnitudes as represented by trends in annual peak river flow have been decreasing in the Southwest, while flood magnitudes in the Northeast and north-central United States are increasing. Confounding the analysis of trends in flooding is multiyear and even multidecadal variability likely caused by both large-scale atmospheric circulation changes as well as basin-scale “memory” in the form of soil moisture.
Droughts too have multiyear and longer variability. Instrumental data indicate that the Dust Bowl of the 1930s and the 1950s drought were the most widespread twentieth-century droughts in the United States, while tree ring data indicate that the megadroughts over the twelfth century exceeded anything in the twentieth century in both spatial extent and duration.

Bob Tisdale, for a change, accepts a climate science paper but for all the wrong reasons.  Here is his final comment:

Yet some members of the climate science community and the mainstream media continue to spin tall tales about weather growing more extreme in recent years. Nothing but nonsense.

First up, in Peterson et al:

  • They only looked at the USA, there is a whole other world out there.
  • The data for heat wave and cold waves only went to 2010 and missed the hottest year on record for the USA, 2012.
  • Flood data only goes to 2008, missing the very wet years in the north east USA that followed.
  • They found that heat waves are increasing and cold waves are decreasing across the USA.
  • The south west of the USA is drying while the north east is getting wetter as predicted.
  • Global warming is in its infancy.  There is a lot more to come.

Extreme events around the world are on the rise

Here is what's been happening all around the world, from Munich Re. Click the chart for a larger version.

Source:  Munich Re: Topics Geo – Natural catastrophes 2012

The future climate for the USA

Regional climate projection is still in its infancy.  Some things are more difficult to predict than others, under different scenarios.  It doesn't mean that no projections are being developed, using climate models.  

Here are indications for temperature change across the USA if the world continues on a higher emissions trajectory and if it moves to reduce emissions, from this EPA website.  Click the image for a larger version.

Here are indications for rainfall change across the USA if the world continues on a higher emissions trajectory, from the same EPA website.  Click the image for a larger version.

After those ominous predictions, I'll make another prediction.  Even if the USA experienced more extreme weather events in coming decades, or even if the south west got a whole lot warmer and drier and the north east a whole heap hotter and wetter, Bob Tisdale would still reject climate science and put it down to magical leaping ENSOs.

From the WUWT comments:

lurker, passing through laughing disputes the findings of Peterson et al, but doesn't say what they disagree with:

August 26, 2013 at 5:15 am  Once again the AGW promotion industry does not allow the lack of facts or data in support of their claim stand in the way of their chosen task.

BarryW is commenting about something else, not the Peterson paper.  There is no chart in Peterson that his comment could relate to.  Maybe he's talking about this:
August 26, 2013 at 5:36 am  Amazing, the slope of the increase since the 70′s is the same as that for the 1919 to 40 period, but the second is due to CO2 and the first can’t be by their theory. Such a perversion of science.

Ric Werme notices the brevity of Bob Tisdale's article, compared to Bob's "normal" and says (excerpt):
August 26, 2013 at 5:09 am  > A Quick Note about Peterson et al (2013)
Wow, it really was a quick note. This must be a first for Bob. :-)

*Bombshell: a jargon word used by both climate bloggers and science rejecting bloggers to denote an apparent 'victory' of the "I've caught you out" kind.  Wrongly applied more often than not.


  1. In fact the paper very clearly says

    At the global scale, trends in extreme temperature events have been found to be outside the bounds of unforced natural variability, leading to a conclusion that they are anthropogenically driven (Christidis et al. 2005; Field et al. 2012; Coumou and Rahmstorf 2012). However, at most subcontinental scales (including the United States), current anthropogenic effects are not sufficient to exceed the effects of natural modes of variability on observed trends in temperature extremes (Brown et al. 2008).

    Strange that Bob decided not to highlight that particular paragraph.

    1. The rest of the world doesn't count.

      He ignored the bit about floods, too. I've read elsewhere that floods don't necessarily reflect extreme precipitation because of improved hydro infrastructure. I'll see if I can dig it up.

    2. It must be the confusion caused by the World Series only including the USA and Canada. Maybe if they invited other countries to participate, Bob and others at WUWT may realise what the term global actually represents :-)

    3. Trying to keep the discussion civil


      And let's not forget:
      WMO, 2013: The Global Climate 2001-2010: a decade of climate extremes. World Meteorological Organization, Geneva, ISBN: 978-92-631-1103-6, 61 p.

      On the other hand, there are some indications that temperature variability may decrease, which may moderate extremely hot temps somewhat.


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