Sunday, February 10, 2013

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 3oC. 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 1oC[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 1.2oC of warming if doubling the CO2 caused a 3oC rise.  Figure 1 in the previous posting showed that the actual warming over this period has only been about 0.4oC. Has the globe cooled by 0.8oC 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 1.5oC above today’s ground level temperatures. By 2046-2065 it is expected to be about 3oC warmer, and by 2080-2099 about 5oC warmer. Thus this region is expected to warm by about 0.6oC 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 0.6oC 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? 

[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
[ix] http://sealevel.colorado.edu/ Accessed January 2013
[x] Fischetti, M. Drowning New Orleans. Scientific American, October 2001, pp34-42
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Thursday, February 7, 2013

A Climate of Scepticism - Part 1



I recently had a piece in Anthony Watt's  Watts Up With That blog.  It attracted a few hundred comments, which was gratifying.  It was written in ordinary language, so used some inexactitudes because I felt that communication was more important, in this case, than precision. Some suggested it should be republished elsewhere - so this is the first part of a long story.

The world has been getting slightly warmer.  Of that there is little doubt.  The measurements by which we know that it is warming are poor.  The figures are not accessible, and keep on changing[i].  Many points at which temperature is measured are badly sited, and bound to give misleading results[ii].  Nevertheless, almost everyone agrees that the world is warmer today than it was 150 years ago.

There are some fairly clear signals of a warmer world.  The Arctic ice is less than it was[iii]. Many glaciers are retreating[iv].  Some glaciers – for instance, those on Kilimanjaro – are shrinking because the long-term precipitation is less than it was 150 years ago, not because it is warmer[v]. Others seem to be shrinking from a warmer climate. There are, however, little data on this[vi].

Where the sceptic differs from many other scientists is in ascribing the warming to human activities – specifically, the burning of fossil fuels and the concomitant rise in the carbon dioxide concentration in the atmosphere.  The hypothesis is that the carbon dioxide traps infra-red radiation that would otherwise escape to space.  This means that some of the energy received from the sun is not lost, and the trapped energy leads to a warming of the globe. 

The physics of how carbon dioxide traps infra-red radiation is well known[vii].  But there are other molecules in the atmosphere that also trap infra-red radiation.  Water vapour is the predominant “greenhouse gas”[viii]. What is not so clear is the extent to which the trapping of energy causes heating.  There are wonderful mathematical models that claim to show how heating occurs.  Unfortunately, all the models suffer from identifiable flaws, a point considered later.

A prime difficulty with the anthropogenic warming thesis is that it is not known how much of the warming is natural and how much might be caused by carbon dioxide.  It is simple to illustrate this. Figure 1 shows the global temperature record as kept by the Climate Research Unit at the University of East Anglia[ix].
Figure 1 Global temperatures, relative to 1950-1990 average

The global temperature dropped from 1850 to 1860; rose until 1880; dropped until 1910; rose until 1945; dropped until 1980; rose until 2000; and has dropped slightly since then.

Figure 2 shows the carbon dioxide record. Careful measurements have been made at Mauna Loa on Hawaii since 1958[x].  The pre-industrial level of CO2 in the atmosphere is generally accepted to have been about 280ppm[xi]. Figure 2 shows a reasonable extrapolation of the data back to about 280ppm in 1800.

Figure 2 Atmospheric CO2 concentrations, measured and estimated.

It is a reasonable assumption that the measured rise is the result of fossil fuel consumption.  Figure 3 shows annual CO2 emissions over time[xii].  It only exceeded 5 billion tons per annum in the later 1940’s.  Thereafter it grew rapidly, passing 10 billion tons in 1963, 15 billion in 1971, 20 billion in 1986 and 30 billion in 2006.
Figure 3 Annual CO2 emissions from fossil fuel consumption.
Comparison of Figures 2 and 3 makes it clear that the rise in atmospheric carbon dioxide is very likely directly related to the emissions from fossil fuels.  However, the low levels of emissions up until about 1945 make it clear that the impact of the fossil fuel combustion prior to 1945 must have been very small if not negligible.  Therefore the changes in global temperatures prior to 1945, shown in Figure 1, were largely natural. The additional carbon dioxide from human activities cannot have played a significant part in the changes prior to 1945.

If most of the temperature changes before 1945 were largely natural, then there is great difficulty in determining how much of the temperature change after 1945 is natural and how much might be driven by increasing carbon dioxide.  This raises the question of what the natural variation in temperature might be.

To answer this question, consider the Vostok ice core record over the past 9000 years[xiii].  The core was sampled every metre of depth, which represented ~20 years of accumulation in the upper layers and ~50 years in the lower levels.  The temperature was estimated from differences in the oxygen isotope ratios.  While a point measurement such as this cannot give a good measure of the average global temperature, it is a reasonable measure of changes in global temperature, and it is primarily temperature changes that are of interest.

The data are shown in Figure 4. There has been a slight cooling over the past 9 millennia, as shown by the least-squares line.  The data were therefore detrended before further analysis – the mean temperature at any one date was added to the reported relative temperature.  The detrended temperatures were what is known as “normally distributed”, i.e. there was nothing abnormal or skewed about them. Then the rate of change between each detrended temperature and the temperature approximately 100±20 years earlier was calculated and expressed as a rate per century.  The results were also normally distributed, with a standard deviation of 0.94oC per century.

Figure 4. Relative temperatures over the past 9000 years.

Thus there is about a 2:1 chance that the temperature may vary by up to 1oC per century from natural causes, but only about a 1 in 10 chance that it will vary by more than 1.9oC naturally. Between 1900 and 2000, it varied by about 0.9oC, which is therefore within the range of natural variation.

And that, in simple terms, is why there is scepticism about the thesis that carbon dioxide is causing global warming – there is no clear signal of any such warming effect.

[iv] Paul, F., Kääb, A. and Haeberli, W. Recent glacier changes in the Alps observed by satellite: Consequences for future monitoring strategies, Global and Planetary Change, Volume 56, Issues 1–2, March 2007, Pages 111-122, ISSN 0921-8181, 10.1016/j.gloplacha.2006.07.007.
(http://www.sciencedirect.com/science/article/pii/S0921818106001603) Accessed January 2013
[v] Mölg, T., and D. R. Hardy (2004), Ablation and associated energy balance of a horizontal glacier surface on Kilimanjaro, J. Geophys. Res., 109, D16104, doi:10.1029/2003JD004338.
[vi] UNEP Global glacier changes: facts and figures. World Glacier Monitoring Service, 2008
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Thursday, December 27, 2012

Severe weather events

It is one of the great perceived truths of today, that severe weather events are on the increase.

If this were so, one would expect more and more people to be dying as a result of floods, hurricanes, typhoons, lightning, snow and all the rest.  There are, after all, many more people than there used to be, so even if the severity of the weather were not on the increase, one would expect more to lose their lives.  Add more people to a hypothetical greater severity, and you would expect many more fatalities - right?

Wrong! Very wrong.  Not only has the risk of being killed fallen, but the absolute numbers dying from extreme events has also fallen:
The average dying each year from extreme weather has fallen from nearly half-a-million a year in the 1920's to about 30 000 a year today.  Extreme events may indeed be getting more frequent, but we engineers have become better at coping with the forces of nature.  So do not be panicked into striving unnecessarily for a low-carbon world - we engineers have already taken the essential precautions!
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Friday, December 14, 2012

Something missing!!

The Second Order Draft of the IPCC's Fifth Assessment Report has now been published (http://bishophill.squarespace.com/blog/2012/12/13/ar5-second-order-draft-leaked.html). 

There is definitely something missing.  The IPCC is supposed to assess the latest peer-reviewed literature and provide a reasoned and balanced review of any differences of opinion.  In the Fourth Assessment, they made much of a prediction that the temperature in the upper troposphere (around 10-12km above the surface) would rise faster than the surface.  Indeed, their models suggested the upper troposphere between about 30 deg N and 30 deg S could warm as  much as 0.6 deg C per decade.  

However, we have been flying weather balloons with thermometers into this region for over 60 years. The measurements show no such warming.  The temperature can also be inferred from some satellite records, extending about 30 years back. These inferred measurements show slight warming, but nothing like 0.6 deg C per decade (and there is also quite a debate about the reliability of the models used to infer temperatures from satellite data).

So all the experimental evidence is against the IPCC's models.  This is particularly surprising, because the physical reasons for a more rapid warming seem sound. 

I would have expected the IPCC to consider this problem in depth.  There are recent publications drawing attention to the problem. For instance, Singer, S Fred, (2011). "Lack of Consistency Between Modeled and Observed Temperature Trends," Energy & Environment, 22, 375-406 stressed the fact that "The US Climate Change Science Program [CCSP, 2006] reported, and Douglass et al. [2007] and NIPCC [2008] confirmed, a 'potentially serious inconsistency' between modeled and observed trends in tropical surface and tropospheric temperatures." He noted further that "Santer's key graph --- misleadingly suggests an overlap between observations and modeled trends. His 'new observational estimates' conflict with satellite data. His modeled trends are an artifact, merely reflecting chaotic and structural model uncertainties that had been overlooked. Thus the conclusion of 'consistency' is not supportable and accordingly does not validate model-derived projections of dangerous anthropogenic global warming." 

Similarly 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 noted "Model results and observed temperature trends are in disagreement in most of the tropical troposphere, being separated by more than twice the uncertainty of the model mean." 

Neither of these critical references are quoted in the Second Order Draft.  Section 2.4.4.2 starting on page 36 of the Draft considers 'Intercomparisons of Various Long-Term Radiosonde and MSU Products.' It concludes that "the differences among the data sets, all of which are uncertain, means there can only be low confidence in the details of the upper air temperature trends."  In other words, because there are differences in the data, the discrepancy with the model predictions can be ignored.

This is not science as I know it.  The models represent a theory.  In my science, observations in conflict with the model show that the model is wrong and must be abandoned.  Here, the observations are being questioned and the model is assumed to be right.  

In a nutshell, at its present stage of development, the Second Order Draft is not to be trusted.  The politicians of this world seem far wiser than normal, in refusing to believe the IPCC's so-called "scientific assessment." These COP bun-fights, such as that just concluded in Doha, are clearly going nowhere while the advisers to the process (namely the IPCC) miss the absolute need to provide unbiased assessments.




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Sunday, December 9, 2012

Dohaha

So the gathering of climate politicians in Doha, also known as COP19, has come to an end with a whimper. Some will cheer the renewal of the Kyoto Protocol, hoping no-one will notice that less than a quarter of all nations have signed up.  It means some bureaucrats will remain employed for a few more years - which is probably a good thing, because otherwise they would have to return to their native land where, no doubt, they would regurgitate all the nonsense about global warming that has been keeping them employed since 1992.

But probably the greatest win will be the demise of a number of NGO's.   They have been an enormous force in the global warming debate.  They achieved their power by a form of blackmail.  Companies confessing to emitting carbon dioxide found it was cheaper to pay the NGO's than to make large cuts in their emissions.  Small cuts, by improving their efficiency for example, brought them some relief from the blackmail and actually improved the bottom line slightly.  But, of course, the NGO's kept asking for ever larger cuts, so the blackmail increased.  It was disguised as "social payments", which reduced the company's bottom line but looked good in the annual report. Overall the shareholders were impoverished but the NGO's got richer and richer.

The net result, however, was that the only people who could afford to go to meetings like the gathering in Doha were the NGO's.  I saw this in Durban two years ago. There were a few businesses, but they were relegated to 'side events'.  Municipalities gathered round the fringe, countries had stalls close to the heat of action, and the NGO's were there in the thick of things, usually as official delegates.

Not surprisingly, the real decision makers have become fed up with this charade.  They jet in for the last few days of such meetings, almost expected to rubber stamp the NGO's decisions reached in dark rooms.  They refuse to play ball; the meeting breaks up acrimoniously and late, and achieves nothing, zilch, nada. This has been the pattern of the last four meetings, and the only result has been ever shriller cries from the NGO's.  A few wimpish countries have made hand-waving promises, which has partly mollified the shrill, but achieving a lower carbon world is far removed.

The US has been mercifully sane in much of this.  It refused to ratify the Kyoto Protocol.  It stuck to business-as-usual.  And guess what - it has achieved what Western Europe and Australia, with all their carbon taxes and Clean Development Mechanisms and carbon trading and you-know-what have failed to do.  It has reduced its emissions to below 1992 levels by the simple application of appropriate technology.  As a result, it now has some of the cheapest energy in the world, and Western Europe is screaming that it can no longer compete on world markets.

So if we tend to laugh at Dohaha, it is with a strong sense of schadenfreude. Lower carbon emissions are not achievable.  Development has trumped ecological scaremongering.  Breathe deeply - CO2 is good for you!
 


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Tuesday, November 6, 2012

How green can you be?

Last night I gave a talk to the SA Academy of Engineering on "The opportunities for low-carbon energy technology for power generation." This was to present preliminary findings on some work an international team and I had been doing for the International Council of Academies of Engineering.  Suppose you desired a lower carbon world.  What could be done to keep the lights on and not see the cost of doing so spiral out of control?

We concluded that, by 2050, it was probably technically feasible to double our use of electricity and yet emit a third less carbon than we currently do. It would mean taking about half our coal-fired power plants out of service, and replacing them by hydropower, nuclear power and some renewable energy. 

At question time there were some sensible questions.  Gratifyingly, my bit of kite flying was not completely shot down in flames.  

And then my heart sank.  A student started to spout the usual collection of green beliefs.  It didn't matter that I had carefully analysed the possibilities, that I had presented a wide range of facts which taken in their totality indicated that it should be possible to reduce carbon emissions without running out of either energy or money. 

I didn't realize, he claimed, what a disaster the world was facing; how it was not enough to start talking about 2050, action was needed now if the world was to survive. We were facing increasing climate disasters that might lead to starvation at the very least.  The Government of Australia and the IPCC had spoken! I should have listened. Instead, what I was proposing was too little, too late.

It was question time, so I hoped he would forgive me if I forgave him for not asking a question, but making a series of statements.  However, it meant I should be allowed to ask him a question.  If things were so desperate, why was it that the world's leaders had failed to reach a decision at Copenhagen four years ago; failed again at Cancun a year later; and decided last year in Durban to wait until 2015 before deciding on actions to be followed from 2020 onwards?  Were the world's leaders wrong? He spluttered something about the world's leaders being nothing but a collection of politicians, which seemed to me a lame response.

But still, the incident rankled.  For once, I had tried to make a positive contribution to what some see as the world's greatest problem.  I don't see climate change that way - I think there are far more present dangers, here and now - but I needed to get to grips with the problem, such as it was.  And here was a True Believer, saying in effect that I had failed miserably, and lecturing me and the hundred or so other members of the audience about his beliefs, his fears, his questionable view of the world.

There comes a time when being green seems to mean that you no longer have to listen to any other point of view - shout loudly enough, and the conversation will be one way, your way. Debate promptly dies, and our world is the poorer.






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