Saturday, April 14, 2018

A chemical engineer’s view of climate change.

We chemical engineers are a privileged group. We are well grounded in chemistry, physics and math. We are used to handling complex systems and understanding the subtleties of their behaviour. We do our best to integrate environmental sustainability into our work. This may surprise those for whom the very word “chemical” is an anathema, but they do not understand the extent of the challenge posed by a cradle-to-grave system for dealing with chemicals. Once the chemicals get to the retail scale, it is extremely difficult to prevent environmental abuse.

Armed with the chemical engineer’s skill set, it is possible to take a unique view of climate change. First, it helps to define what we understand by “climate change”? The hypothesis is that an increase in the greenhouse gas concentration in the atmosphere will increase the scattering of longwave infrared which would otherwise radiate harmlessly into space. The resultant imbalance in radiative fluxes would lead to heating of the atmosphere. Both the increase in greenhouse gas concentrations and heating are observable, but it does not necessarily follow that the two are linked.

It is further supposed that the relative humidity will increase in a warmer world, and, because water vapour is a strong greenhouse gas, the rate of heating will increase exponentially. Intuitively, this makes sense. However, young chemical engineers soon learn that to every problem in a complex system there is always a simple straightforward solution – and that solution is always wrong!

The chemical engineer understands that feed forward disturbances in complex systems will indeed easily run out of control, and that there has to be feedback if the system is to be stable. The temperature control of the Earth is impressive. For any 100-year period during the past 8 000 years, the system has controlled itself within a range of ±2oC for more than 95% of the time. Climate science has been concentrating on the feed forward aspect, and seems to have completely neglected the stabilizing feedback mechanisms.

The world does appear to be warming. The official records claim to demonstrate this conclusively:
But there are a couple of problems with this official graph. If you take something like New York’s climate, and show the diurnal and seasonal changes, the official record looks insignificant:
That is “global warming”. Does it really look like a crisis? But worse is to come! Like a good chemical engineer, you check on the underlying data. You find, when you do this check, that the HADCRUT curve is a figment of someone’s imagination! The raw data has been “adjusted”. Cape Town’s data, for instance, shows slight cooling since 1880, but after adjustment the picture is dramatically different:
By ignoring the pre-1910 data and lowering the 1910 to 1960 data by exactly 1.21oC, the observed cooling has become a hypothetical warming! There are hundreds of sites to which similar “adjustments” have been made. A recent report observed “The conclusive findings of this research are that the three GAST [Global Average Surface Temperature] data sets are not a valid representation of reality.” HADCRUT is one of those three.

If you are a good chemical engineer, once your suspicions are aroused, you go very carefully. So when you are told “Extreme weather events, natural disasters and failure of climate change mitigation and adaptation” are high-ranking risks, you search for evidence in support. You go, for instance, to the climate bible, the Reports of the Intergovernmental Panel on Climate Change. There you find such warnings as:
• “There is low confidence that any observed long-term increases in tropical cyclone activity are robust
• “There is low confidence in observed trends in small-scale phenomena such as tornadoes and hail”
• “There is limited to medium evidence available to assess climate-driven observed changes in the magnitude and frequency of floods. Furthermore, there is low agreement in this evidence, and thus overall low confidence at the global scale regarding even the sign of these changes.” (Emphasis added)
• “Uncertainty in projections of changes in large-scale patterns of natural climate variability remains large.”

Now I ask you to imagine your Board’s reaction if you were to ask them for a few hundred million to address the risks posed by climate change, as assessed by the IPCC. You would probably be lucky to keep your job.

However, some Board members may have been reading Al Gore or similar science fiction. “What about the melting ice/sea level/ malaria/polar bears/coral?” And you would show them the evidence that the glaciers are only a few hundred years old – they come and go; that the sea level has been rising at about 1.7mm per year for as long as we have been able to measure it; or that, in 1923, malaria caused 10 000 deaths in Archangel, just outside the Arctic Circle; or that polar bear populations had been declining because too many hunting permits had been issued, and have since grown back; or that bleaching of corals is primarily due to short-term sea level changes such as those caused by El Nino.

They may fall back on the law. “We have signed the Paris Agreement!” But the Paris Agreement is about controlling temperatures, and that is something we chemical engineers know a lot about. The target is to control the Earth’s temperature to less than 1.5oC above some pre-industrial temperature. Look again at the first figure. The most recent data – which probably hasn’t been adjusted – shows a perfectly natural 0.6oC rise caused by El Nino. And our politicians are going to show us how to control to less than 1.5oC? Plus/minus how much?

But where we chemical engineers get really annoyed is when there are predictions about the future climate based on models. We do a lot of modelling. It is key to consistently producing chemicals of clearly defined properties from inputs of surprisingly variable composition. We maintain that quality in spite of plant disturbances, failed sensors, dramatic phase changes, ageing pumps. Our models work in real time.

The climate “models” fail. They all tell us the upper troposphere between the tropics should be warming faster than the surface of the earth. It isn’t. They can’t take into account the energy release of a single tropical cyclone, so their energy balance errs by a few zettajoules. We chemical engineers cringe at the amateur attempts to do modelling. If a model is demonstrably wrong, you should fix it before you go any further.

So what do they do with their failed models instead? They run them many times, and average the bad results. Then they use the average bad results to make predictions – invariably of worsening conditions. The extraordinary thing is that people believe them. Perhaps it is easier to create a putative problem than to rebuild a bridge or replace an ageing dam or heighten a sea wall.
Hans Andersen wrote a fable of the emperor’s non-existent new clothes. If Andersen were still alive, he would be amused to see his tale come true.

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