Wednesday, July 11, 2012

Welcome, hurricanes!

Well, Daniel has been reduced to a tropical depression, but 2 hurricanes are predicted to bring us rain by the weekend, right in the middle of the dry season.

I don't think it is generally appreciated how much we depend on destructive storms for our drinking water. It probably wouldn't surprise you to think that on the leeward side, where there are only about 10 rainy days a year, that most of the moisture comes during torrents, usually from konas during the winter.
 
But it might surprise you to know that 95+% of rainfall even on the windward side comes on just a few days a year, even in places where it rains somewhat on over 200 days a year. Nevertheless, that's the case, also.
 
The reason is that big storms carry hard-to-conceive amounts of water in them. The flow of Nahiku Stream varies by a factor more than 1,000: the difference between 8 million gallons and 9 billion gallons.
 
Big raised limestone areas like Florida and Yucatan would be uninhabitable without hurricanes to renew their groundwater. But because they are big, they pay the price of having to absorb destructive winds. Hawaii is small and so gets the benefit of the storms' rain without having to endure the storms, except every 20 years or so.
 
In Makawao, where I live, it has rained at least 30 days, and probably more, I haven't been keeping a record, since May 1. In most years, it hardly rains at all from May to Thanksgiving. Last summer, it rained often, too, though not as often as this year.
 
The total accumulation has not been great, although perhaps that will change over the next several days.
 
But such swings make nonsense of claims that car exhausts are changing climate. Maybe they are, but you'll never prove it by citing exceptional weather.
 
Of course, that hasn't stopped the panic-mongers. They are busy trying to show that, for example, the heat wave in the east is 20 times more likely than it was in the '60s. Whatever that means. I used to live in the East, and there were heat waves back then, and frequently.
 
But not every year.
 
Heat waves are frequent now, but not every year.
 
I was startled, last week, when NPR began a lengthy report on drought in Texas. The surprise was that the report was about a drought in the '50s. In other words, long droughts in Texas are normal. Nothing to do with car exhausts.
 
For a few minutes, I thought that NPR had converted to common sense, but no. It was an aberration. Today, their science reporter, Richard Harris -- a true believer in catatrophic global warming -- had a report on how extreme weather events are more likely than they used to be -- despite the obvious fact that they are not happening more often than they used to.

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