Friday, March 15, 2013

crisis creep

The North Coast of California typically has very stable weather and a stable weather pattern.  We are used to foggy summers and bright autumns, and rainy winters.  Lately we'd had sunnier summers, which is a little weird but hard to argue with.  And in recent years our winter rains have been starting later and later.  Until this winter when, so far, they haven't come at all.

Even our big December storm--with winds so unusually ferocious that they destroyed my basketball hoop stand which had survived many previous winters--brought very little rain to Arcata.  So far this calendar year it has been unusually warm and sunny, with clearer and colder than usual nights.  It felt more than weird.  It became oddly nerve-wracking.  It doesn't feel natural.

The National Weather Service stats bear out this impression.  Though compiled for nearby Eureka, they generally pertain.  January and February--usually the heart of the rainy season--were together almost 8 inches below normal rainfall (as figured since 1981.)  The deficit since July is 4 inches.  The February average rainfall is 5.63 inches.  We got 1.78.

The stats for Arcata in March aren't promising.  We're an inch of rain in deficit already.  It's possible that we'll have a rainy six weeks through the end of April. (Winter was late last year, too, but I'd need to see some good stats to convince me this hasn't been even drier.)  This change in our cycle is undoubtedly already having effects, and will continue to change things large and small.

Compared to the huge effects elsewhere: the sweltering summer heatwaves and fires, hurricanes and perfect storms, floods and huge snowstorms, this is small potatoes.  But small changes can lead to big ones.

It's easy to see the linear effects: less rain, less groundwater.  Less snowpack in the mountains, less runoff into the rivers for summer.  Less moisture in the forests, more potential for fires and firestorms in the ordinarily dry season.

But the nonlinear effects are harder to see, like the change in the lifecycles of animals and plants, right down to insects and fungi.  There's no particular documentation right now on what has pet owners hereabouts talking, which is the sudden influx of fleas and flea allergies in pets, and the resistant nature of those fleas.  Not earthshaking, unless your cat is important to you and you are spending unusual amounts of money on its health.

But elsewhere the effects are clearer, if not the causes just yet.  Scientific American recently ran a story (picked up by other outlets) about a "mysterious" fungus that's killing bats in 21 U.S. states and five Canadian provinces.  Killing some populations at the rate of 70% to  100%.   So who cares about bats?  Insects do, which means that all kinds of agriculture does. "Bats have an important role in regulating insect populations, a function that is vital to successful agriculture. A recent study found that the loss of North American bats could lead to agricultural losses of more than $3.7 billion per year. "  And really that's just for starters.  Insect-borne diseases may seem like ancient history but they very quickly could be very bad news.

The SA story makes no connection to climate change.  But there are other documented disasters that do.  The northern pine beetle has been devastating forests in the northern U.S. and Canada, killing trees at ten times the rate of any previous epidemic.  These beetles are highly evolved to be tree killing machines--they communicate and work together to do it.  But they were previously limited by cold temperatures in these northern mountains.  Now they aren't.  A 2012 New York Times story (when it still had environmental reporters) put it this way:

Because of warming in the West, the voracious mountain pine beetles have moved to higher elevations over the last 25 years. In the 1970’s they did not live at altitudes above 9,000 feet, but they are now found at 11,000 feet and even higher because winter temperatures there are not cold enough to kill them. It is a serious problem because trees above 9,000 feet have not evolved to deal with the bugs and therefore have few defenses. “

This was a story a year ago because it was about to get worse.  Some beetles were breeding twice in a summer instead of once.  Just this week forestry officials in South Dakota are meeting to make dealing with these beetles their top priority.

These kinds of effects of climate change can be the butterfly wings of the climate crisis: seemingly small perturbations that eventually make huge waves.
      

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