Global Warming Mechanisms — Room For Debate
When I sent my letter to the NZ Skeptic (Spring 2003), I did not expect vehement denials in the next issue. Such debate is, of course, healthy and occasionally useful. My letter, though, was not intended to cover the whole subject; merely to offer some points to ponder. The responses have been rather more thorough, and I feel I must defend my position.
I must also defend Bjorn Lomborg from Alan Ryan’s critical comments. Sadly, he fell foul of an attack instigated by the most recent editor of Scientific American. The prejudiced intent of this was shown by the choice of authors, who included Stephen Schneider (who has made a fortune writing books promoting AGG global warming), and E Wilson, who has been pushing an eco-catastrophe barrow for years. This was followed by a kangaroo court called the Danish Committee for Scientific Dishonesty — which had among its members not one scientist — and which severely criticized Lomborg, apparently purely on the basis of the Scientific American article. The Danish Ministry of Science later declared Lomborg not guilty of either bias or dishonesty.
Next, I must agree with Kerry Wood that the world is warming; that CO2 is a true greenhouse gas and is increasing in the atmosphere, and that (in theory) this should be a powerful mechanism for retaining atmospheric heat. However:
- AGGs are only one variable — and not necessarily the dominant one.
- When the AGG hypothesis is used as the basis for climate models, the calculations don’t make sense. For example, by their reckoning, the 20th Century should have warmed by well over 2°C. The actual warming was 0.6°C.
- Other observations do not support the idea that AGGs dominate global temperature change. The current bout of global warming began around 1700 to 1720. In NZ, coastal glaciers like the Franz Josef began retreating about 1750. Greenhouse gases didn’t increase at all till 1850, and only to a negligible degree until about 1920. From 1940 to 1976, global temperatures fell, to the extent that Time published a special edition on “The Forthcoming Ice Age.”
Three main systems are used to measure global temperature: averaging meteorological station results; averaging weather balloon readings; and averaging satellite temperature measures (available since 1979). The latter two methods agree with each other startlingly, and show very little global temperature rise since 1979. The first method shows clear, linear temperature increases from 1920 to 1940, and then from 1976 to the present. Most measurements are taken in cities or airports, which have been growing larger for many decades, hence increasing the local warming effect of tar and cement.
AGGs contribute only 0.3% to the greenhouse effect. By far the greatest impact comes from water vapour, which averages about 300 times the insulating effect. Yet in conventional global warming models, variations in water vapour are considered unimportant.
The major alternative hypothesis to AGGs is increasing solar output. While direct (and very recent) measurements of this show too small an increase to explain global warming, it is also true that the sun does not change by small increments. Instead it is characterised by occasional spectacular changes — sunspots, flares etc. The sudden temperature increase in 1976 is better explained in this way.
During the “Little Ice Age” of 1600 to 1700, the sun experienced the “Maunder Minimum” in which almost no sunspots were seen. In 1998, which was hailed as the hottest year for many centuries, there was also increased sunspot activity. New Scientist (December 20, 2003) reports that high sunspot activity correlates with a drop in the price of English wheat, and this has been true over many centuries. This makes sense if sunspots coincide with warmer periods.
I do not want to appear to be offering a “proven” mechanism for global warming. Instead, please read my comments as simply a reminder that there is much, much more that we do not know about climate change than that which we do. Global warming — yes. Mechanism? We still do not know. (Abridged)
Lance Kennedy, Tantec
Greenhouse Gas/Climate Link Unproven
The consensus “Summaries for Policymakers” adopted line-by-line by Governments, which appear at the beginning of the various reports of the Intergovernmental Panel on Climate Change (IPCC) have never stated that there is a proven relationship between emissions of greenhouse gases and any harmful climate trend.
Instead they have resorted to ambiguous, non-committal statements like “The balance of the evidence suggests a discernible human influence on global climate”, which does not mention greenhouse gases as part of the “human influence”, and is merely a “suggestion”.
You have to go to Chapter 1 of the 2001 IPCC report to find the real truth, which is:
“The fact that the global mean temperature has increased since the late 19th century, and that other trends have been observed, does not necessarily mean that an anthropogenic effect on the climate has been identified. Climate has always varied on all time-scales, so the observed change may be natural.”
Recent reported temperatures are less than recent estimates for the “Medieval Warm Period” 1000 years ago, so they could be due to natural variability. At least part of recent “warming” has been attributed to the unusual El Niño ocean patterns.
Computer-based climate models, based on the absurd assumption that greenhouse gases are the only influence on the climate, have very limited predictive value, a point that is admitted by Kerry Wood, who mentions the IPCC projected range of 1.4 to 5.8 degrees mean temperature increase for the year 2100. He should know that this range could easily be extended further by choosing slightly different values for the many uncertain parameters in the models. The IPCC, actually, discourages the use of the word “prediction”, and prefers “projection”, which is based only on a particular set of assumptions, some of which can be absurdly exaggerated.
Emissions of greenhouse gases must have some effect on the climate, together with changes in the sun, cosmic rays, volcanoes, ocean circulation, and other human effects such as land-use changes and urban development. Without a greater knowledge of all these factors it is foolish to believe that restricting greenhouse gas emissions is likely to have any worthwhile positive change to our climate.
Vincent Gray , Wellington
Bjorn Lomborg – Misunderstood?
Bjorn Lomborg certainly touched off a powder-keg when he implied that the environmental movement could do with a session in the sweat lodge and a little critical self-assessment, and the very title of the book neatly co-opts our organisation into the debate whether we like it or not, and we probably do. The letter from Alan P Ryan directly criticises Lomborg and that by Kerry Wood indirectly. (1318, NZ Skeptic 70).
I am somewhat at a disadvantage as I have lent my copy of The Skeptical Environmentalist to a statistician friend who, before reading the book, was also of a critical inclination towards Lomborg’s arguments, along with a lot of the scientific community. But if my memory serves me well vis a vis climate change, Lomborg was not making the claims attributed to him. The criticism solely relates to the statistics but no one that I have read addresses the at least equally important aspect of the book, that of social policy. This book is about who will serve and who will eat, a very proper point of enquiry for a politics department of any university. Lomborg’s thesis, common throughout the book, is: before we go and spend a king’s ransom on Kyoto et al, let us make sure we are getting value for money. There is no end of good causes to spend public money on: glue ear operations, PKU tests for newborn children, vaccinations or even a campaign to stamp out religious stupidity — all cheap and effective in improving the general lot of mankind, but unfortunately not sexy. Saving the Earth of course is sexy, as are international conferences to discuss same. The social effects of a focus on such lovely big problems, where it is not possible to falsify assertions in any meaningful time frame, while fun, are most damaging. Smaller but nonetheless significant matters like income distribution, social justice etc, all fall beneath the pall of climate change and saving whales et al, in the same manner that Aids activists usurp R&D money at the expense of other perhaps more pressing epidemics.
I digress. Lomborg, I believe, simply states that climate change, global warming even, is happening and that the relevant question is how much and what does this mean. Your correspondent Wood states the problem fairly: “Beyond the basics, climate change is hellishly complex and far from fully understood”. No one disagrees, not even The Skeptical Environmentalist. Vladimir Putin nailed his colours to the mast recently, claiming that a bit of global warming would be a good thing for Russia. If the matter is so little understood and the modelling so variable, why not save our money so that we might spend it on problems in the here and now, not in 2100. When we have fixed the problems right in front of our faces we can proceed to the new and improved problems that will no doubt appear in the years to come. Reading the book might be a good skeptical start.
Alastair Sims, Hahei
Parliamentary Commissioner for the Environment on the Right Track
Poor Bruce Taylor! You can’t please everyone, but the Parliamentary Commissioner for the Environment (PCE) does make an honest effort to please most of them. Certainly, nothing in his reasoned article in the Spring, 2003 Skeptic warranted Vincent Gray’s diatribe in the summer 1318, which reads like a potpourri culled from the Old Testament, Mein Kampf and the worst of that archpriest of greenwashers, Bjorn Lomborg.
His anthropocentrism stems from the anti-Darwinian notion that evolution is teleological; that man is the apotheosis of an imaginary Grand Design. Worse still, he seems to envisage (Gaia forbid!) a future superman spawned solely by his limited notion of ‘science’. His rejection of pluralism and the social contract is pure Fascism.
Analogy is at best a metaphor for an underlying reality; it may be useful for simplifying a difficult concept, but it can never stand on its own as an explanation: the more so in Dr Gray’s case where the analogy is itself false. The only self-aware species is the misnamed Homo “sapiens”; we alone can invent ‘moral values’ from abstract concepts. So the first part of his letter is merely so much Social Darwinism and anthropomorphising sociobabble.
He believes that moral values have no place in modern society. Let’s indulge in a little thought experiment. Suppose a mad scientist has succeeded in cloning a human-machine hybrid to use as an Asimov-style robot. Would Gray be happy with this, or would he suddenly discover that he has values?
His second section begins: “Progress … depends on improved emphasis on human moral values … human rights … and a continued advance of science and technology”. Well, just so and who could argue with that? Certainly the PCE doesn’t so argue, other than in Gray’s imagination. Or does he really believe that possum dust proposals would influence their decisions?
I am a scientist and a dedicated atheist but I know that religious beliefs, socioeconomic considerations and cultural sensitivities should be considered, though they should not be allowed to predominate over the scientific evidence where this is strongly at variance with them. Fortunately, there is no evidence to suggest that this is happening. Vicki Hyde’s excellent editorial in the spring ‘Skeptic’ provides a balanced view on this topic.
A recent report in Nature predicts that a quarter of all species will become extinct by 2050 because of global warming. This estimate doesn’t include the effect of habitat loss, increased pollution and downstream ecological disturbance on an already over-stressed biosphere. Even the Pentagon has now released a report expressing doubt that the USA could survive the consequences of global warming. What Gray and his like ignore at the peril of the majority is that humans are not separate from the rest of “creation” but a part of it.
Alan P Ryan, Kaiapoi
Did the convenors of the first Annual Meeting of the German Skeptics (GWUP) know that they were setting themselves up to hold their 13th Conference on Friday, 13 June, 2003?
Bernard Howard, Christchurch