Thursday, June 27, 2013

Future climate: wither our weather?

          According to conventional models of climate change, adding greenhouse gases (GHG) like carbon dioxide to the atmosphere will trap heat close to the earth's surface, warming it. Such warming is expected, among other effects, to increase the speed and intensity of the hydrological cycle. The cycle can be visualized as a great wheel turning in the sky. Water vapor absorbs energy from its surroundings (latent heat of vaporization). As the climate warms more energy becomes available to transform water into vapor. A warmer atmosphere is also capable of holding considerably more water vapor than a cooler one: the capacity is strongly dependent upon temperature. These facts imply that precipitations, too, should become more violent too.

                A sped up, intensified hydrological cycle is exactly what we have been witnessing the last few decades. The big wheel in the sky turns faster and faster because the flow rate has increased..

                 Witness recent reports, articles and warnings by Swiss RE, the world's largest "re-insurance" company. (Re-insurers are, in effect, mega-insurance companies which insure smaller client insurers, the insurance company you buy your insurance from). In the financial sector Swiss RE may not be God, but at least an archangel. And they take climate change to be a serious challenge for their industry in the future: 

                   For the past week the (somewhat arid) prairie province of Alberta has been the scene of record breaking floods. 75,000 residents were forced to evacuate the great city of Calgary and only now are returning to the downtown core a week later, often without power. Preliminary property damage estimates range from 3 to 5 billion dollars and direct economic losses are pegged at another 2 billion. That's about 6 billion dollars for a province with 3.6 million people or $1,500 per capita - for a single extreme weather event! These, of course, constitute some of the "hidden costs" of non-sustainable development based on non-renewable energy sources like coal, oil and natural gas. (Another way of viewing such costs: as "hidden subsidies" to pollutors who are deferring the costs of pollution abatement equipment onto the backs of the innocent victims of pollution.)

                  Here's what's really got Swiss RE in a knot. A sped up hydrological cycle raises flood damage risks for flood plain construction, sites near rivers chosen for their scenic beauty for example.

                   Your prime value property may not be worth much if the wheel continues to spin faster and faster..

                   Will the Alberta floods of 2013 be the wake up call..


                    For a 2 minute video of what the mayor of the beautifully (and aptly) named High River, Alberta calls their "catastrophe":

                    Critical infrastructures have been damaged as a result of the water logging and erosion of river banks. A train carrying an environmentally dangerous cargo has been derailed on a sagging flood damaged bridge in Calgary, for example.

                    What will the future climate look like? No one really knows! Even if one can make generalized predictions based on computer models (General Circulation Models), local conditions - microclimate, topology and hydrology - may modify, attenuate or amplify predicted climate change patterns. The Rocky Mountains amplified the effects of heavy rains by concentrating flow patterns on their down slopes and augmenting flow velocities due to gravity. Landslides caused some damage to property. In at least one case hydrology has been modified permanently: a landslide changed the path of local streams..

                     The following article and video describe the convergence of several factors which make for a Perfect Storm. The miracle is that so few lives were lost (four so far)..

                      Here, then, are the real hidden costs of non-sustainable development in Alberta: a plausible scenario, at least. Global warming (GW) leads to wintertime "blocking patterns" in which the jet stream remains static for unusually long periods. This, in turn, can lead to heavier than normal snowfalls, increasing mountain snowpack depth. Then comes the GW warmed spring with higher than traditional temperatures to rapidly melt all that snow. What made 2013 a real bomb was the fact that, this year, spring thaw was delayed. When abnormally rains hit hard last week, they triggered catastrophic melting of the enlarged winter snowpack. I think they call it a Perfect Storm. This is exactly the type of unpredictable, locally variable climatic zaniness that the GW hypothesis claims is in store for us all..

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