Saturday, January 5, 2013

Superstorms - A New Phenomenon?

In the wake of "superstorm" Sandy, there seems to be a growing perception that storms of this power, capable of such massive damage, are a new phenomenon.  Some want to argue that these "new" storms are an effect of global warming, and represent an unprecedented threat to humans.  Such notions are not supported by the science of meteorology, however.  Rather, they represent a human failing that I like to refer to as "temporal myopia" - if some event hasn't happened in my personal life experience to date, then it evidently represents something dramatically different and unprecedented!

The simple reality, evident to anyone who studies the weather, is that powerful storms have occurred many times in the recorded past, and there's no reason to believe they were generally weaker than the big storms happening of late.  The historical weather records include events that were even more powerful than, say, Hurricane Katrina or "Superstorm" Sandy.  The fact that big, dangerous storms have happened in the historical past is clear and compelling evidence that they'll happen again!  Superstorms of the sort represented by Sandy are not new!!  The science has yet to establish whether global warming will increase the frequency and/or severity of storms, so any idea that storms definitely will be worse in the future as a result of climate change remains in the realm of speculation, not established scientific conclusions based on compelling evidence.

What I've said so far ignores the storms that occurred in the time before historical weather records were kept - if such a record were available, even stronger storms than in our historical records are sure to have happened.  When your paltry few decades of personal experience fail to include such an event, this isn't even close to showing that an "unprecedented" event has occurred recently.  It's ignorant and even a little arrogant to think that our brief human experience encompasses everything the atmosphere can do to us.  And, of course, what I've said also ignores really bad storms that happen in some other country, that might pop up briefly in the news but then vanish from the collective public memory.  If it happened in another country, it might as well not have happened at all (a "spatial myopia" that is also common).

Some colleagues and I are completing a scientific reanalysis of a "Super" tornado that happened on 18 March 1925 - the so-called Tri-State Tornado.  This single tornado killed more people (695, according to official accounts) by far than any other tornado in the US historical record.  Nothing quite like it has happened since.  Nevertheless we can be absolutely certain that a tornado of that duration and violence inevitably will happen again - we just can't say where or when.  Only a tiny handful of people alive today have experienced a tornado of that magnitude.  Nothing anyone has experienced since 1925 comes very close - but someday, someone will.

The terrible suffering inflicted by Katrina and Sandy is awful to consider and difficult for anyone not so affected to even imagine.  Lives lost, homes destroyed, treasured possessions lost, communities devastated - only those who have experienced it for themselves can possibly understand.  A common thread in interviews with survivors is the almost universal comment about losing their sense of security.  They were vulnerable, of course, all along - that sense of security was an illusion!  This Earth is not benign (nor is it malevolent) - only indifferent.  When humans find themselves in the path of a powerful storm, it's purely a matter of being unlucky, and not because some evil force is intent on destroying them.   Being lucky in the past is no guarantee your luck won't someday run out, especially if you put yourself in a particularly vulnerable position.

Survivors often tend to cling to the notion that they survived the very worst the atmosphere could have thrown at them.  This is another illusion, unfortunately.   Whereas they were unlucky to be in the path, they were actually fortunate the storm was not the worst possible storm.  Had it been much worse where they were, they might not have survived!  No one has ever experienced "the worst possible storm" in all of human history!  Even worse storms than Katrina and Sandy are awaiting new victims in the future.  It's just a matter of time.

The biggest factor contributing to the massive damage and dislocations caused by these powerful storms along our seacoasts (and in floodplains along rivers) is the relentless development and exploitation of such low-lying zones for profit.  Building structures in these areas is tantamount to inviting inevitable disaster from storm surge, and/or heavy flooding rains, and/or winds (without regard to whether the storm is a tropical cyclone or an extratropical cyclone or a "hybrid" cyclone).  People have been trying to call attention to these hazards for construction along our seashores (and floodplains) for decades - and unfortunately, the predictions of disaster have been almost completely ignored!  When the inevitable happens, it inevitably catches many victims by surprise!

We can no longer afford to allow rebuilding in these threatened areas.  This is not like living in "tornado alley" because we can never anticipate just where and when tornadoes will hit - even in the areas of highest frequency, you could live there a thousand years and never even see a tornado!  But living in low-lying areas along seacoasts (and in river floodplains) is comparable to living on the flanks of an active volcano or along an active earthquake fault zone.  Disaster is inevitable and it makes absolutely no sense to rebuild in that same bulls-eye once again.  Insurance should not be allowed in such hazard zones, nor should the residents receive government aid to rebuild in the same locations - if aid is to be given, it should only be to rebuild somewhere outside of the danger zones.

The threat from future storms can be reduced by some common sense preparations, but most important is the need to abandon obvious hazard zones.  Only then can we be said to be "storm ready"!