Sunday, July 29, 2012

A Level of Concern

So cable TV has a function after all.  I caught a talk on public access given this past spring here in Arcata--the kind of event I never take the trouble to attend or even know about--by a scientist for the Forest Service, Michael Furniss, talking about sea level rise and its impacts, especially locally but elsewhere, too.  I learned a lot in several different ways.

I learned more about why this amazing oasis of summer (it's cooler than usual if anything, rarely breaching 65F) will probably remain an oasis for the climate crisis of this century.  That's partly because the big earthquake that is likely to hit in this century will have greater impact than just about anything the climate crisis can throw at us, short of total polar ice loss and a sea level rise of 200 ft.  But it also goes beyond our coastal climate.  We have and will likely have enough water.  We aren't dependent on mountain snow melt, which is declining.  He believes, contrary to some recent studies, that we're not losing moisture via fog, and that there's good reason to believe that fog will actually increase. (High fog--the "marine layer"--is an almost daily feature here, like right now as a matter of fact.)   Which is good for the redwoods (which depend on moisture from fog) and he says since they've probably been here a million years, they're likely to survive.

On sea level rises, he notes that another factor that has to be considered is the land level rising or falling, which it naturally does.  Right now the land is rising in Sitca, Alaska faster than the sea level.  But the land level is lowering in Galveston, Texas.  Like sea levels, land levels are the product of complex interrelationships and forces, but even more locally determined than sea levels along a given coast.

He notes that globally, sea levels have changed a great deal over the Earth's history--responding for example to Ice Ages--but they've been relatively stable for the past 6,000 years: pretty much all of human civilization.  So the idea that it can change is not part of our history. 

In judging sea level rises, one of the factors is that warmer water takes up more space--and this thermal expansion is basically what the IPCC calculated in their initial prediction of about a 1 meter rise by 2100.  They didn't even attempt to figure in ice melt, it was too controversial at the time.  Now others have made those calculations, and that roughly doubles the rise, to over 2 meters.  That's without rapid melt, the kind scientists are worried about now because of this summer's news from Greenland and Antarctica.  That might result in a 10 to 15 meter rise in a few decades.

Sea levels have been slowly rising for the past quarter century, and this is accelerating because of the climate crisis.  At first the impact will be felt only in extreme events--"perfect storms" that involve periodical tidal events--when the extremes are more extreme, leading to greater flooding that seen previously.

But by the end of the century, the impact will be enormous, even with the most conservative estimates (he notes, by the by, that projections for Humboldt Bay don't change very much from a 1 meter to a 2 meter rise.)  The San Francisco Bay area is very vulnerable.  The airport will be under water, for one thing.  Much of Florida will be inundated, and the U.S. East Coast hit pretty hard.

Elsewhere in the world it's even worse, especially in Vietnam, Bangladesh, other southeast Asian countries.  He notes that in Asia there is no debate over the climate crisis.  The discussions are on what to do about it.

As for our neck of the woods, the information is incomplete but is coming.  Some areas that I would have thought were vulnerable turn out not to be, but others really are: like a lot of highway 101, our link to the outside world, and especially Arcata's link to Eureka and points south.

Some solutions involve engineering, but he warns against taking a total concrete and steel approach--you can't build seawalls everywhere (rivers that need access to the sea are a big problem) and a lot of ecological analysis, land analysis, etc. has to be done to protect against unintended consequences.  Even if there is enough money to do it.

Furniss ended on a note of optimism.  The changes will take place over decades, presumably with enough time to respond intelligently.  His last slide said simply, " We are adaptable.  We'll be okay."  But he also noted (without making a big point of it) that financial support for research into what to do is lacking.  Significantly, local scientists are doing almost all the local research on possible impacts as a volunteer effort, and not part of their regular jobs.

So I don't take away the idea that it won't be so bad, in due course things will be okay all on their own.  The disruptions will be enormous, even in much less than worst case scenarios.  They will require concerted and dedicated attention.  But they will occur over time, and so they will be the work of people over the next decades, even apart from responding to particular crises and events caused or made worse by the climate crisis.  But it's really really time to get started in a bigger way.

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