Volcanoes, climate and the limits of computer modeling
Scarce a week goes by without some scaremongering headline about climate change, premised on apocalyptic conclusions drawn from a computer-generated climate model. Modeling lies at the heart of the whole vast climate-change industry, an industry sparked by the big government-backed computer modeling centers in the US and UK. To understand the frail connection between these models and the realities of world climate today and tomorrow, consider the crisis in world travel and aviation prompted by the Eyjafjallajokull volcano in Iceland.
The current eruptions began on March 20; the plume of ash from the larger, ongoing eruptions that began on April 14 led to systematic grounding of international and local European flights, losing airlines billions in revenues and paralyzing the travel industry.
There are very well-documented cases from the 1980s of volcanic ash — i.e., microscopic jagged particles of pulverized rock — bringing jumbo jets within minutes of disaster. The US leaves the airlines to decide whether it’s safe to fly, whereas European governments say Yea or Nay, based on computer models from the Volcanic Ash Center in London and Eurocontrol, an organization that coordinates air travel.
But as red ink spread across the airlines’ balance sheets, and passengers bunked down for days at hubs like Frankfurt, questions about computer modeling of the extent of the potentially lethal plume became more insistent. Exactly how far had the plume extended? How come monitoring planes were reporting safe conditions in areas the models were identifying as no-fly zones?
Computers at the Met Office, which earlier forecast a “barbecue summer” last year and a mild winter for this year, produced a stream of maps predicting the ash would cover a vast area, eventually stretching from Russia to Newfoundland. But across almost all of it, there was virtually no ash at all, and none visible to satellites. (It didn’t help that the main monitoring plane was laid up for a paint job.)
“We never understood why a blanket ban had been imposed — something that would not have happened in other parts of the world,” a senior airline executive said to The Mail on Sunday. “Safety is always our paramount concern, but this seemed like over-caution gone mad. As the days went by without the restrictions being lifted, we became more and more concerned that the policy was based on theoretical models which had little grounding in reality.”
I called Pierre Sprey, a defense analyst with a background in statistics and a healthy skepticism about climate modeling, and he gave a dry laugh. Back in the 1970s, Sprey had done some environmental consulting and speedily learned firsthand the insuperable difficulties of a seemingly elementary assignment in air pollution: modeling the behavior of a plume drifting downwind from a single smoke stack. “It was a vastlier simpler problem than some generalized climate model, but still hopelessly intractable” when it came to predicting the downwind dispersion of the plume and its toxic constituents.
Sprey found, to his surprise, that the useless air pollution models he was dealing with in the early 1970s were actually based on WWII models developed to predict the behavior of chemical warfare weapons being tested by the British at Porton Down back in the 1940s. What emerged with finality from those tests was that there was no knowing where the poison gases might head, and indeed one powerful inhibition against the use of chemical weapons has always been the ease with which, amid a sudden shift in the wind, some act of stupidity by the gassers can end up killing one’s own troops, as unforgettably described by the poet Siegfried Sassoon in his WWI memoirs.
Contrast the demonstrated impossibility of computer modeling the simple downwind dispersion of a plume from a single smokestack or volcano with the mind-boggling scientific hubris of trying to model the climate of the entire globe.
Here we start with endlessly faulty data — from instruments parked on urban “heat islands” to severely massaged data bases of daily temperature readings, from sketchy numbers for the vast reaches of the planet where there are almost no readings, to expurgation of decades of inconvenient data. Then these are meshed with models constructed around bad thermodynamics, baseless suppositions about the hugely dominant heat effects of water vapor and clouds, and hopelessly inaccurate quantifications of carbon uptake by the earth’s forests and oceans.
These quack science models are further skewed by the modelers’ doctrinaire anti-carbon passions, the vetting of their results by the corrupt bureaucracy of the UN’s IPCC and the dependence of their salaries on the expectations of funding agencies.
Small wonder, then, that the modelers’ computer “reconstructions” of the planet’s past climate conveniently wiped out the well-documented three-centuries-long Medieval Warming Period, as well as the subsequent 500 years of Little Ice Age — nor is it surprising that their terrifying computer prognostications in the IPCC’s 2001 Third Assessment failed to predict the next decade’s absence of any global warming trend at all.
Alexander Cockburn is co-editor with Jeffrey St. Clair of the muckraking newsletter CounterPunch. ‘ 2010 Creators. com