Computer modelling: fraud at the heart of science

Scarcely a week goes by without some scaremongering headline about climate change, premised on apocalyptic conclusions drawn from a computer-generated climate model. Modelling lies at the heart of the whole climate-change industry, an industry sparked by the big government-backed computer modelling centres 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 the systematic grounding of international and local European flights, losing airlines billions in revenues and paralysing the travel industry.

There are very well documented cases from the 1980s of volcanic ash - ie, microscopic jagged particles of pulverised 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 Centre in London and Eurocontrol, an organisation that co-ordinates air travel.

But as red ink spread across the airlines' balance sheets and passengers bunked down for days at hubs like London and Frankfurt, questions about the potentially lethal plume - all based on computer modelling - became more insistent. Exactly how far had the plume extended? How come the airlines' own monitoring planes were reporting safe conditions in areas the models were identifying as no-fly zones?
 
Computers at the Met Office, which forecast a 'barbecue summer' last year and a mild winter for this year, produced a stream of maps predicting that 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 told 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."

The inherent limitations of modelling were starkly displayed by the experiences on the night of February 28, 2000 when the crew of a DC-8 used for atmospheric research discovered first-hand that ash plume forecasts are not perfect. Here's how Peter Spotts of the Christian Science Monitor (April 18, 2010) described the incident:

"The DC-8 was en route to Kiruna, Sweden, for the start of a research study of atmospheric ozone over the Arctic. Some 35 hours earlier Iceland's Mt Hekla volcano had sent clouds of ash and steam soaring to altitudes of 45,000 feet.

"The DC-8 was cruising at just more than 500 miles an hour at 37,000 feet and some 200 miles north of where the plume was predicted to extend. But the highly sensitive research sensors aboard the craft detected a sudden rise in ash particles and sulfur dioxide. For seven minutes, the craft flew through a tenuous ash cloud some 800 miles from the volcano.

"The only visual clue they had: they couldn't see stars in the night sky, a common phenomenon when flying through high-altitude cirrus clouds. Cockpit instruments reported no unusual engine behavior. The crew smelled nothing unusual. And they saw no other visual clues that would tip them off to the presence of volcanic ash. The crew reported the encounter to air-traffic controllers and continued to Kiruna."

An initial inspection on landing disclosed no apparent damage. It was only later, back at home base, that "deeper inspections showed that internal cooling passages had been clogged, with some of the engines' areas of highest temperature showing signs of unusual heat stress. In essence, all the engine's internal parts were coated with fine white powder. The leading edges of turbine blades were pitted. The build-up of heat from clogged cooling passages blistered coatings on several internal components.

Moreover, some research suggests that if the plane had encountered the ash in daylight, the crew still might have had no visual clue because the ash could well have been encased in ice, looking like high-altitude cirrus clouds. The bottom line from the research team: "The insidious nature of this encounter and the resulting damage was such that engine trending [readings from in-flight instruments] did not reveal a problem, yet hot section parts may have begun to fail [through blade erosion] if flown another 100 hours."

The plume had spread in entirely unanticipated ways, ways that seem obvious after looking at photographs of the Eyjafjallajokull eruptions. Take a look at both the ground level and satellite pictures of the plume and you'll understand the hopelessness of modelling the peculiar vagaries of the plume: swirls, layering, branching, etc. Every aspect of this well-described incident defies computer modelling and prior turbine design knowledge: the plume was somewhere that would never have been predicted by a model, the ash particles were ice-encased, the expected turbine blade erosion damage didn't show up.
 
I called Pierre Sprey, a defence analyst with a background in statistics and a healthy scepticism about climate modelling, and he gave a dry laugh. Back in the 1970s Sprey had done some environmental consulting and speedily learned first-hand the insuperable difficulties of a seemingly elementary assignment in air pollution: modelling the behavior of a plume drifting downwind from a single smoke stack. "It was a vastly simpler problem than some generalised 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 behaviour 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 modelling 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 databases 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 vapour 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 modellers' 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 modellers' computer "reconstructions" of the planet's past climate conveniently wiped out the well-documented three-century-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. ·