Thursday, March 8, 2012


Amidst all the swirling controversy regarding anthropogenic global warming (AGW), a subplot has arisen that involves me rather more directly than most of the science regarding global climate change.  In particular, some climate scientists (among them is Dr. Kevin Trenberth) have been making what I believe to be highly speculative claims about the climatology of severe weather in a world affected by AGW.  The essence of the situation is that Trenberth has been claiming in various media that there will be more tornadoes in an AGW-influenced future, and that the "tornado season" will start earlier and be more violent than ever.

In my studies of severe convection and tornadoes, I have not been willing to make any statement regarding the potential impact of AGW on the occurrence frequency of tornadoes.  Why so cautious?

First, the existing record of tornado events is seriously problematic, even here in the US - it's much, much worse outside the US, unfortunately.  The existing record of tornado occurrences simply will not support any speculation about trends in the observed events, in large part because the existing record is overwhelmingly dominated by non-meteorological artifacts in the data.  I've spent the last 40 years exploring that record (along with several colleagues, including Dr. Harold Brooks).  I have a number of peer-reviewed publications related to the topic of severe storm and tornado climatology.  Those data simply don't allow us to make any statement whatsoever about long-term trends.

Second, although it seems likely that increasing global average temperatures would increase evaporation, making the average atmospheric humidity rise and thereby making it possible for increased thermal instability and possibly stronger updrafts in thunderstorms, there are some other factors associated with AGW that could mitigate that.  In particular, with the AGW being more pronounced in the polar regions than near the equator, the result would be a decrease in the horizontal temperature contrast between the poles and the equatorial regions.  That, in turn, would result in a decrease of vertical wind shear.  Decreasing vertical wind shear would be notably unfavorable for the development of tornadic supercells.  There might be an increase in overall severe storm activity because of increased buoyancy, but the resulting storms might be less likely to become tornadic.

Third, the details of just what a future dominated by changes from AGW would be like remain speculative.  There could be regional variations in the frequency of conditions favorable for tornadoes, irrespective of what the global average conditions might be.  Thus, tornado frequency in some regions might increase, and yet could decrease over most regions, leading to an overall decrease - that is,  some areas could buck that global average trend and actually show an increase in frequency.

I've been a consistent supporter of the consensus of global climate change scientists regarding AGW.  This is because I have no research findings of my own that could gainsay that very strong consensus.  I know some of the scientists who are part of that consensus and I have great respect for their work.  The general findings regarding AGW are consistent with what I know about meteorology, but climate change is not my domain of expertise.  It would be foolish for me to dispute the findings of the consensus represented by the IPCC reports, since (a) this is outside my domain of expertise and, (b) I have no rational evidence-based reason for such a dispute.  What evidence I see is overwhelmingly supportive of the consensus, which is why I believe it's such a strong consensus.

But in the case of tornadoes, a few climate scientists (e.g., Dr. Trenberth) are overstepping their domains of expertise.  If I give them the respect that their work is due in an area within which I have no record of peer-reviewed publications, I would expect them to do likewise regarding the work I (and my colleagues) have done in an area wherein these climate scientists have no record of peer-reviewed publications.  I don't speculate about global climate change, so I have every reason to expect them not to engage in unfounded speculation about tornado occurrence frequency.

Tuesday, March 6, 2012

It doesn't work that way? Oh, really?

In discussions with christian believers, a huge sticking point for me is the absence of credible evidence for the "god hypothesis" (GH).  Atheism is not necessarily a belief system, it's the absence of belief.  This point is one that many religious believers have considerable difficulty understanding - it takes no belief to be an atheist - only the absence of belief in a supernatural deity.

When atheists challenge the beliefs of believers, the believers often respond with something along the lines of "We may not be able to prove to you that god exists, but you can't prove that he doesn't exist!"  This is a classic misunderstanding of atheism:  that we can offer no absolute proof of the nonexistence of god doesn't require us logically to believe in that deity's existence.  Many atheists acknowledge that we can't produce such a proof.  We accept that since we can't do so, others logically can choose to believe their god exists.  Most atheists are not out to convert believers to non-believers, since experience suggests that, for the most part, such efforts are fruitless.  Rather, we simply want to point out the irrationality of most religious beliefs and to explain why we choose not to buy into them.  Moreover, we consider the burden of proof logically is on the believer, not the disbeliever! 

And we expect that believers shouldn't push their beliefs into the lives of those who don't accept those beliefs.  I'll stop posting my opinions when believers stop posting theirs.

There are two aspects to freethinking that are characteristic of atheists: 

1.  Arguments on behalf of some idea should be rational.  They need to follow the rules of logic.  They need to make sense.  They need to be as free as possible of unfounded speculation.  They should encompass no contradictions.
2.  Arguments should be supported by evidence, if possible.  When considering an idea, a rational analysis of any idea based on a rational argument often leads to logical expectations that can be tested by collecting evidence and comparing that evidence to those expectations.  If that evidence is consistent with some hypothesis, then it's plausible to accept that hypothesis provisionally, until new evidence is found that contradicts the hypothesis.  This is, in a nutshell, the scientific method.

One aspect of the GH is that it usually involves such things as infinite knowledge, infinite power, and infinite benevolence.  When considering such infinities, many believers fail to appreciate the potential for logical traps and pitfalls when dealing with infinities, such as the classic question "Can god create an object he can't move?"  These sorts of problems are brushed aside as sophistry by believer apologists, but I find them a challenge to the logic of most believers.  It's the infinite nature of these attributes that's troublesome for non-believers, whereas believers seem all too willing to accept these assumptions with little more than perhaps a twinge of doubt.  Those infinities lead necessarily to contradictions that demonstrate the irrational (and, therefore, implausible) nature of the GH as expressed by christian believers.

The "evidence" that atheists can marshal to bolster their disbelief is, not coincidentally, an absence of evidence on behalf of the GH.  An absence of evidence makes it logically consistent to declare an absence of belief!  If the putative deity were demonstrating its existence by its actions every day so that everyone on Earth could see the evidence for themselves, then we'd have no need for the tens of thousands of religious denominations that exist today.  That hypothetical deity would be making its needs and concerns known directly to all of us on a daily basis.  Belief would not require faith at all - rather, it would be a demonstrable reality.  Belief would be rational, and based on routine experience.  The absence of that everyday evidence is a strong argument in favor of disbelief.  Why would an omnibenevolent, omniscient, and omnipotent being, creator of the universe and all within it, choose to make it so difficult to believe in that being?  What would be the point, anyway?  Why, in its infinite benevolence, would it create humans only to subject them to eternal torment?  Such a deity would be considered criminally psychotic if it were human!

Instead, we're told "It doesn't work that way.  Our deity has no wish to make it easy to believe in him!  He wants us simply to accept the idea of his existence on faith alone!  Faith is the test we have to pass!"  Fine - if that's what you believe, it conveniently allows you to "apologize" for the utter lack of evidence supporting your beliefs.  The humans who created your belief system made it possible - no, mandatory! - to explain away any absence of compelling evidence; to rationalize it by making belief in the absence of evidence a virtue, instead of an unfulfilled requirement for acceptance.  Actual controlled, scientific tests of the efficacy of intercessory prayer, for example, have failed to show any beneficial effect (and, in some cases, have shown some tendency toward negative effects!).  These tests are dismissed by apologists, saying something like "Our god doesn't work that way!  If he actually answered all prayers (as promised in the bible, by the way), there would be clear evidence of his existence!"  So I'm supposed to accept that kind of nonsense?  If your god 'doesn't work that way' so as to provide unambiguous reasons to believe in him, then the GH doesn't work for me!  The complete and utter absence of any credible evidence on behalf of the GH is enough for me to choose disbelief in the GH.  I haven't "proven" the non-existence of your deity, but I've challenged you to accept the burden of proof to convince me otherwise.  You offer no credible evidence to convince me and seem to be arguing that this actually makes logical sense!  No - it fails utterly to make any sense.   I've stated what evidence it would require to convince me of validity of the GH and it's not forthcoming.  What evidence would it take for you to disbelieve, as I do?  Are you willing to admit that no evidence would ever convince you to disbelieve, thereby confirming the irrationality of your position?  Then we could agree to disagree.

Monday, March 5, 2012

Why do I do what I do?

I just finished giving two presentations to two different groups within a few days of each other.  I think my talks went over well - at least based on the comments I received afterwards.  I also just finished reading a wonderful book about the 1925 Tri-State tornado that I'll soon be reviewing here.  And this nation again suffered a major outbreak of killer tornadoes (on 2 March).  This all got me to thinking about why people seem to appreciate the messages that always underlie my presentations.  It's my belief that the reason people respond favorably to my talks is that I say what I'm thinking, without sugar coating or resorting to innuendo to make a point.  I'm saying what many people want to say, but most of them feel too inhibited to say such things.  I decline to be so inhibited.

It was a long-standing goal of mine (since high school, actually) to be able to say what I think without having to censor myself for fear of offending someone.  When I earned my doctorate in 1976, I decided I'd reached that point, and I've never looked back or regretted that decision.  Yes, being outspoken has earned me a certain amount of enmity in certain circles and probably cost me a promotion (that I didn't really need).  The fear that many people have about speaking their mind may be unfounded in at least some cases, but that fear of retribution for being outspoken leads to self-censorship.  Of course, some people may indeed be punished in important ways for speaking their minds.  If so, I feel fortunate to have not been punished in any way that really mattered to me.  What I'm grateful for is that I've been able to be an advocate for certain things and a public critic of other things without any fear of retribution.  So when I take a clear and unequivocal position on something, there often seem to be people who let me know they're pleased that someone has been willing to say what I've said.  Of course, not everyone agrees with my positions.  For some reason, most of them decline to debate the issue with me, or even to disagree with me openly.  I much prefer they say what's on their minds, and I certainly have no means to visit retribution on anyone for disagreeing with me openly.  So the relatively scarcity of opposition bothers me because I always learn things from a rational argument, even when the outcome is that we agree to disagree.

Recent tornado outbreaks have reinforced many of the things that a few of us have been concerned about all along:  the danger of staying in mobile homes, the greedy opposition of the mobile home industry to any legislation that would seek to do something about the problem, the greedy opposition of the construction industry to changes in building code that would make buildings more resistant to damage from tornadoes and high winds, the management practices that inhibit the National Weather Service from doing the best possible job, and so on.  As a science professional, I feel obligated to share my opinions and my reasons for having them (typically involving scientific evidence).  I consider that a requirement associated with my duties.  Anything less would be a disservice to those who are depending on what my science can contribute to the welfare of society (worldwide).  My real obligation is to my science, not to any particular organization to which I might belong.  If I stay true to the science, the rest takes care of itself.

Reading the terrible tragic stories associated with tornadoes makes my participation in this science much more personal to me. The stories from the 1925 Tri-State tornado have an eerie similarity to stories about the most recent tornado outbreak.   I already know that I can't possibly understand how tornado survivors feel, simply because it's never happened to me.  For me, it's no longer possible to see these powerful weather phenomena in the same light as when I first began my career.  I began to grasp (however dimly) the devastating impact they can have on real people after the Union City tornado of 1973, when my chase team drove into the damage in the wake of the tornado (see item #32 here).  It adds an entire new dimension to realize that science isn't just a game I'm playing with the atmosphere - it's a process that can contribute something important to the society that has paid my bills for all these years.  I can give something back and offer some hope that in the future, society can be better prepared to prepare for and deal with these events.  Therefore, it's my duty to be as outspoken as possible.  I simply can't tolerate anything that would inhibit our society from doing its very best to respond to these tragedies in the most effective possible fashion.