The opinions of politicians, singers and film stars on the state of the climate and what should be done about it, are eagerly sought by the populist press. As a partial consequence of this, the populist press is becoming less and less popular.

On the other hand, the ABC and other leftist media organisations are quick to dismiss climate realists who do not have science qualifications. According to them, if you are a climate alarmism sceptic, you only have the right to express your views if you have an advanced degree in a relevant field of science. And even then you don’t because your scepticism marks you out as ‘not a real scientist’ or ‘in the pay of the oil companies.’

Point out that science is not decided by consensus but by evidence, that every citizen has the right to discuss matters of public policy, and that in any case, there is no consensus amongst climate scientists that the world is warming in an unusual or alarming way, and you will be greeted by the equivalent of fingers poked in ears, looking away and shouting ‘I can’t hear you.’

If that doesn’t work, they will try to stop you speaking at all, suggest you be imprisoned or tattooed so everyone can see you coming and avoid you, or even suggest you should be gassed or your children blown up if you persist in your dangerous derangement.

This is derangement in the same sense that anyone in Germany who disagreed with Nazism, or in Soviet Russia with Stalin, was thought by the state to be deranged, and dealt with accordingly.

Just don’t say you think their proposals sound like fascism, because then you really will be in trouble. Greenies apparently believe it is OK to act like a fascist. But that it is not OK, in fact grossly unfair and horrible and like, really mean, man, for anyone to point out that they are doing so.

But facts are stubborn things. And scientists with integrity can be stubborn as well.

One such scientist is Dr William Happer, Professor of Physics at Princeton University.

He has written a longish article called The Truth About Greenhouse Gasses, in the current edition of First Things magazine.

Here are a couple of paragraphs:

I want to discuss a contemporary moral epidemic: the notion that increasing atmospheric concentrations of greenhouse gases, notably carbon dioxide, will have disastrous consequences for mankind and for the planet. The “climate crusade” is one characterized by true believers, opportunists, cynics, money-hungry governments, manipulators of various types—even children’s crusades—all based on contested science and dubious claims.

I am a strong supporter of a clean environment. We need to be vigilant to keep our land, air, and waters free of real pollution, particulates, heavy metals, and pathogens, but carbon dioxide (CO2 ) is not one of these pollutants. Carbon is the stuff of life. Our bodies are made of carbon. A normal human exhales around 1 kg of CO2 (the simplest chemically stable molecule of carbon in the earth’s atmosphere) per day. Before the industrial period, the concentration of CO2 in the atmosphere was 270 ppm. At the present time, the concentration is about 390 ppm, 0.039 percent of all atmospheric molecules and less than 1 percent of that in our breath. About fifty million years ago, a brief moment in the long history of life on earth, geological evidence indicates, CO2 levels were several thousand ppm, much higher than now. And life flourished abundantly. …

We conclude that atmospheric CO2 levels should be above 150 ppm to avoid harming green plants and below about 5000 ppm to avoid harming people. That is a very wide range, and our atmosphere is much closer to the lower end than to the upper end. The current rate of burning fossil fuels adds about 2 ppm per year to the atmosphere, so that getting from the current level to 1000 ppm would take about 300 years—and 1000 ppm is still less than what most plants would prefer, and much less than either the nasa or the Navy limit for human beings.

Yet there are strident calls for immediately stopping further increases in CO2 levels and reducing the current level. As we have discussed, animals would not even notice a doubling of CO2 and plants would love it. The supposed reason for limiting it is to stop global warming—or, since the predicted warming has failed to be nearly as large as computer models forecast, to stop climate change. Climate change itself has been embarrassingly uneventful, so another rationale for reducing CO2 is now promoted: to stop the hypothetical increase of extreme climate events like hurricanes or tornados. But this does not necessarily follow. The frequency of extreme events has either not changed or has decreased in the 150 years that CO2 levels have increased from 270 to 390 ppm. …

Let me summarize how the key issues appear to me, a working scientist with a better background than most in the physics of climate. CO2 really is a greenhouse gas and other things being equal, adding the gas to the atmosphere by burning coal, oil, and natural gas will modestly increase the surface temperature of the earth. Other things being equal, doubling the CO2 concentration, from our current 390 ppm to 780 ppm will directly cause about 1 degree Celsius in warming. At the current rate of CO2 increase in the atmosphere—about 2 ppm per year—it would take about 195 years to achieve this doubling. The combination of a slightly warmer earth and more CO2 will greatly increase the production of food, wood, fiber, and other products by green plants, so the increase will be good for the planet, and will easily outweigh any negative effects. Supposed calamities like the accelerated rise of sea level, ocean acidification, more extreme climate, tropical diseases near the poles, and so on are greatly exaggerated.