Global warming?

When you hear the word "consensus" reach for your gun

(Victorian Farmers Federation, Morwell, June 8, 2005)


“There is every reason to believe that the variability of global temperature and other climate characteristics experienced over the past century are part of the natural variability of the climate system and are not a consequence of recent anthropogenic activities.”

William Kininmonth, "Climate Change: A Natural Hazard", 2004, p. 134

Facts they don't want you to know                          Some balancing views                         Selected references

Contemporary discussion of climate change is bedevilled by dishonesty. The views of the public are fashioned largely by propaganda promulgated by self-interested NGO, media, industry and political pressure groups. At the same time, scientific opinions are strongly conditioned by the fashionable political requirement that research has to be "useful" to merit funding: no climate change problem, then little climate change funding.

Most western governments base their climate change policy on the advice of the United Nations Intergovernmental Panel on Climate Change (IPCC). Though in receipt of copious amounts of scientific advice, the IPCC (at the level of its "Advice to Policymakers" document) is an unabashedly political, not scientific, organisation. Its assertion that a dangerous human influence is being exerted on climate change rests on three main pillars, each of which has been demonstrated to be unsound. These are (i) the thermometer-based ground-temperature record; (ii) the claim, after the Mann et al. (1998) "hockey stick" model of climate change, that late 20th century temperatures rose to an unnatural level and at an unnatural rate; and (iii) the claim that deterministic computer models can predict climate 50 or 100 years ahead.

The focus of IPCC activity has been on comparing contemporary climate change with that of the last 1,000-2,000 years. This is a ridiculously short and atypical period over which to seek to understand climate change.

From studying climate records over the last several million years, palaeoclimatologists and palaeoceanographers have established a sound understanding of the natural patterns and some of the mechanisms of climate change. The most important evidence comes from sediment cores from beneath the deep seafloor and ice cores through the Greenland and Antarctic ice caps. Generally agreed inferences from these data are:

1. That 5 million years ago (Ma) planetary temperatures were several degrees warmer than today.

2. A gradual decline in temperature has occurred since. Superimposed on this decline since 2.5 Ma have been substantial glacial and interglacial climate fluctuations. These resulted from the waxing and waning of ice-sheets over high latitudes in both northern and southern hemispheres, the timing of which (20, 41 and ~100 thousand years (ky) spacing - termed Milankovitch frequencies) was controlled by changes in the earth's orbital geometry.

3. For about the last 0.6 million years, the glacial-interglacial oscillations have occurred on the 100 ky-scale. For more than 90% of that time earth's mean temperature has been cooler, and often much cooler (~5-10 degrees), than today. Warm interglacial periods comprise less than 10% of the time, and on average lasted only ~10 ky. Civilisation and our modern society developed during the most recent warm interglacial period (the Holocene), which has already lasted 10 ky.

4. Superimposed on these longer term climatic cycles are (i) shorter-term cyclic oscillations on all scales between the 11-yr sunspot cycle and ~1, 2 and 5 ky cycles of unknown origin; and (ii) episodes of abrupt climate change, when climate changed across almost the full glacial-interglacial range in a period as short as a few years to a few decades; the causes of abrupt climate change also remain largely unknown.

5. Changes in temperature and atmospheric carbon dioxide, which can be measured in ice cores, occur in close parallelism. In detail, however, over both annual and long-term glacial-interglacial periods, changes in temperature PRECEDE changes in carbon dioxide. Thus carbon dioxide cannot be a primary forcing agent for temperature change.

6. Compared with the ancient climate record, and especially that of the last 20 ky glacial to interglacial change, modern temperatures are neither particularly high nor particularly fast-changing. Indeed, temperatures in Antarctica for the three interglacials which precede the Holocene were respectively about 5, 4 and 6 degrees warmer than today.

Because of our lack of understanding of many parts of the climate system, and because of the non-linearity of climate processes, deterministic computer models, on which the IPCC relies so heavily, are unable to provide meaningful predictions of future climate states. As Richard Lindzen, lead-author of Chapter 7 in the Third Assessment Report of the IPCC (2001) has observed: “The General Climate Models (GCMs) are just experimental tools, and now these tools are (being) forced to make predictions that they are not able to ….. There is nothing wrong with the GCM modellers, they do the best job they are able to. The problem is that too many people believe in the unreliable predictions. The problem is thus not scientific, it is political".

Four alternative predictions of near-future climate, based on empirical models drawn largely from the palaeoclimatological record, are described. Three agree that the likely trend during the 21st century is one of cooling, and the fourth (based on Milankovitch predictions) predicts cooling over the longer term. In keeping with the generality of these predictions, the averaged global surface temperature has been falling for the last 6 years.

Climate change has always occurred and always will. Citizens are right to be concerned about the possibly deleterious effects of both the warmings and coolings which lie ahead. As with most potential natural disasters, however, the appropriate action is to have in place reactive response plans to manage the change when it occurs. Australian federal and state greenhouse offices should be disbanded. Some of the funds saved could be reallocated to Climate Response Planning organisations. These should give high priority to preparing policy advice on how to better manage Australia's water and agricultural resources, and urban growth, as climate change inevitably occurs. Attempting to stop climate change is an expensive act of utter futility.

Press Review, Melbourne Age  

Return to Comment & Opinion