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.

A climate of scepticism - Part II

The first part of this piece described the weakness of the hypothetical link between increasing carbon dioxide and increasing global temperatures.  In this part, I consider the question of whether there are models which can strengthen the hypothesis and whether those models can tell us anything about other aspects of climate such as rainfall.

The proponents of the anthropogenic warming thesis claim to have models that show how added carbon dioxide will lead to a warmer world[i].  There are major problems with these models, not least of which is the fact that the proponents claim that doubling the CO₂ in the atmosphere will increase the temperature by over 3^oC. This is well above any physical reason[ii]. It results from arguments about the effect of water vapour in the atmosphere, which is supposed to exacerbate the effect of increased CO₂. 

The doubling effect is so far invisible.  Other estimates have suggested that doubling the CO₂ may increase the global temperatures by less than 1^oC[iii].  The evidence for this is building. For instance, there has been about a 40% increase in atmospheric CO₂ since 1945, which would imply perhaps 1.2^oC of warming if doubling the CO₂ caused a 3^oC rise.  Figure 1 in the previous posting showed that the actual warming over this period has only been about 0.4^oC. Has the globe cooled by 0.8^oC while the added CO₂ has been warming us? It seems unlikely.

There are further reasons to doubt the models.  For instance, Figure 5 reproduces Figure 10.7 from the IPCC Fourth Assessment Report[iv]. The sections are from the South Pole on the left to the North Pole on the right.  In the atmosphere, altitude is expressed in terms of pressure, with sea level at 1000hPa and 11km being about 200hPa. Stippling on the figures shows regions where all the models agree within narrow limits.

Figure 5. Model predictions of global temperature changes: atmospheric upper, oceanic lower

The area of particular interest is the ‘blob’ in the atmosphere over the equator and centred at about 200hPa. In 2011-2030 it is just less than 1.5^oC above today’s ground level temperatures. By 2046-2065 it is expected to be about 3^oC warmer, and by 2080-2099 about 5^oC warmer. Thus this region is expected to warm by about 0.6^oC per decade, if the models are to be believed.

For about the last 60 years, balloons carrying instruments have been flown into this region to obtain data for weather forecasts.  Examination of the temperature records has failed to reveal any heating whatsoever[v].  Satellites have been flown since the late 1970’s, and some of their views through the atmosphere can be interpreted as average temperatures of particular regions[vi].  The satellites show very slight warming – but nothing like 0.6^oC per decade.

In science, a single experiment can suffice to disprove a theory.  Any theory whose predictions fail experimental tests must be abandoned without further ado. In the present case, the anthropogenic warming hypothesis has led to theoretical models, but those models have failed experimental proof.  Such is the strength of belief in the anthropogenic thesis, however, that the modellers are most reluctant to abandon – or even revise – their models. This is one of the strongest reasons for scepticism.

The anthropogenic thesis has also led to many predictions of the possible conditions in a warmer world.  Some, such as the impact on the cryosphere, seem to be borne out. However, the models which, as noted earlier, are highly suspect, suggest such things as dramatic changes in precipitation.  The evidence is negligible.

For instance, there is a very long record of rainfall for England and Wales, shown in Figure 6[vii]. There is absolutely no sign of any change in the rainfall pattern over the last 60 years. Over the entire period, the annual average over 25 years is 913 ±42mm. The 42mm is the maximum deviation, not the standard deviation!

Figure 6. A 240-year rainfall record

Similarly, there are repeated suggestions that the sea level will increase rapidly due to the melting of ice and the warming of the oceans (warm water is less dense than cold, so it occupies a larger volume).  It is true that the sea level is rising, but you seek in vain for any evidence that it has risen significantly faster since 1945 than before.  Figure 7 illustrates this, using the tide gauge data from New York which extends back to 1858 with a gap from 1879 to 1892[viii]. The regression line for all the data from 1870 to 2011 has a slope of 2.947mm/a; that from 1945 to 2011 has a slope of 2.948mm/a.  There has been no significant increase in the rate of sea level rise at New York for the past 140 years.

Figure 7. A 150-year sea-level record.

Many of the fears about sea level rise are unfounded.  Yes, the sea is rising slowly.  Satellite measurements since the early 1990’s confirm a rate of rise of about 3mm/a[ix]. However, there are already defences against the sea. It is necessary to allow for tides, storm surges and even tsunamis.  The existing defences are measured in metres, not mm. An increase in the average level of 3mm/a can be offset by raising the defences by an additional brick every 30 years or so. The rising sea level is not a threat.

Of course, there are events where the defences prove inadequate.  This was the case when Hurricane Katrina struck New Orleans.  Several years previously, it had been reported that the levees were likely to fail[x]. They were old, and lacked modern design features. They failed, as anticipated, when the storm surge arrived. Their failure had nothing to do with ongoing rise in sea levels, and everything to do with weak defences. 

However, there are repeated references in the literature to the New Orleans levee failure being the result of “climate change.” This illustrates a feature of the debate that reinforces scepticism.  Disasters that have nothing to do with a changing climate are ascribed to “climate change” as a means of raising awareness about the supposed threats. Do we need to have our awareness raised? Or isn't it better just to be sceptical? 

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[i] Randall, D.A., R.A. Wood, S. Bony, R. Colman, T. Fichefet, J. Fyfe, V. Kattsov, A. Pitman, J. Shukla, J. Srinivasan, R.J. Stouffer, A. Sumi and K.E. Taylor, 2007: Climate Models and Their Evaluation. In: Climate Change 2007: The Physical Science Basis. WG1, Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S. et al, (eds.)]. Cambridge University Press, Cambridge

[ii] See Randall, D.A. et al, op cit p. 640: “A number of diagnostic tests have been proposed…but few of them have been applied to a majority of the models currently in use. Moreover, it is not yet clear which tests are critical for constraining future projections (of warming). Consequently, a set of model metrics that might be used to narrow the range of plausible climate change feedbacks and climate sensitivity has yet to be developed.”

[iii] Spencer, R.W. and Braswell, W.D  Potential Biases in Feedback Diagnosis from Observational Data: A Simple Model Demonstration, J Climate 21 5624-5627, 2008 DOI: 10.1175/2008JCLI2253.1

[iv] Meehl, G.A., T.F. Stocker, W.D. Collins, P. Friedlingstein, A.T. Gaye, J.M. Gregory, A. Kitoh, R. Knutti, J.M. Murphy, A. Noda, S.C.B. Raper, I.G. Watterson, A.J. Weaver and Z.-C. Zhao, 2007: Global Climate Projections. In: Climate Change 2007: The Physical Science Basis. WG1, Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., et al (eds.)]. Cambridge University Press, Cambridge

[v] Douglass, D. H., Christy, J. R., Pearson, B. D. and Singer, S. F. (2008), A comparison of tropical temperature trends with model predictions. Int. J. Climatol., 28: 1693–1701. doi: 10.1002/joc.1651

[vi] Spencer, R.W. and Christy, J.R. 1992: Precision and Radiosonde Validation of Satellite Gridpoint Temperature Anomalies. Part I: MSU Channel 2. J. Climate, 5, 847–857.

doi: http://dx.doi.org/10.1175/1520-0442(1992)005<0847:parvos>2.0.CO;2 Accessed January 2013

[vii] http://climexp.knmi.nl/data/pHadEWP_monthly_qc.dat Accessed January 2013

[viii] http://www.psmsl.org/data/obtaining/rlr.monthly.data/12.rlrdata Accessed January 2013

[ix] http://sealevel.colorado.edu/ Accessed January 2013

[x] Fischetti, M. Drowning New Orleans. Scientific American, October 2001, pp34-42