Greenhouse sceptics (also called "climate sceptics", "climate change deniers", "greenhouse denialists" or "contrarians") have been a very important part of climate change policy in Australia. As a serious, almost self-taught, climate scientist, it is impossible for me to accept any cause except man-made global warming (and possibly stratospheric ozone depletion) for observed rainfall changes over Australia since 1968 because neither the instrumental record since 1885 nor the few Holocene paleoclimate records show parallels. While I actually agree with the problems greenhouse sceptics have with climate models, in a way rare among those who do believe in global warming, I am willing to suggest the possibility increased greenhouse gases will cause much greater changes (at least in rainfall) than any model suggests.
Most "believers" in global warming have a tendency to view greenhouse sceptics as a small group of industry-funded scientists whose motivation is preserving corporate profit. There is a general perception that those without a direct vested interest in the production of greenhouse gases cannot be greenhouse sceptics.
Greenhouse sceptics are much more numerous than a few businessmen. Moreover, the share of greenhouse sceptics in the Australian population is very likely to increase in the future because the small conservative sector of the population producing most future children consists very substantially of greenhouse sceptics. Most people who would consider themselves greenhouse sceptics are not scientists, but neither do they work for road transport, oil, coal, aluminium or titanium industries.
“Typical” greenhouse sceptics are ordinary working people concerned with making enough money to improve his or her standard of living. Most sceptics are fairly poor but have never relied on welfare, typically working what left-wingers in universities would consider long working hours to gain enough money for a large family house in the outer suburban "mortgage belt". Prices for the most basic necessities like food and housing are thus the essential issues for them.
A natural consequence is that greenhouse sceptics believe very firmly that any regulation by government of the economy is wrong. Private entrepreneurs, sceptics believe, will always be more efficient at using any resource as efficiently as possible: private property rights as the most essential right of all and public regulation - let alone public ownership - produces inherent inefficiencies that never solve the problems their advocates intend. Most sceptics believe that government should eliminate itself from wealth redistribution, education, health care, transport, housing, and even water supply, so that these services can be provided by what they call the "natural family", private charity or private enterprise. Greenhouse sceptics have much higher levels of charitable giving and voluntary contribution than advocates of global warming, and they are more likely even to return incorrect change or offer basic help with directions.
The philosophy underpinning this belief is known as the "Austrian School". Austrians believe that every exchange of commodities or services must be absolutely voluntary. Government taxation or regulation is called "coercion" by Austrians and equated with violence. Greenhouse scepticism is a natural result of the beliefs mentioned in the previous paragraph. When one believes all government interference to be unethical, laws to reduce emissions of greenhouse gases are seen as a particular egregious form of coercion, as is protest for radical change to achieve reductions. Consequently, Austrians (and many other conservative Christians) cannot believe anthropogenic global warming the disaster other scientists view it. A few Austrians hint in a quite far-fetched way at assigning private property rights to the atmosphere - which in Australia would mean requiring people to live without electricity or cars at all - but most believe global warming will have positive impacts and will mean longer growing seasons in cool regions, many fewer deaths from cold weather, and improved crop yields from higher levels of carbon dioxide.
In short, greenhouse sceptics, rather than being materialist businesspeople primarily motivated by money, are actually simple working people whose scepticism is caused by their firm belief in nonaggression that does not allow government regulation of private property. I myself have debated with a sceptic at RMIT - and feel I have benefitted greatly in my ability to argue in favour of man-made global warming!