The perfect essay on climate change

Every now and then I come across someone else's work that is so good I want everyone to read it. This essay, by Richard Lindzen and William Happer, is one such. They are supremely eminent scientists, and their current status is given at the end. Yes, they don't give references, but then neither do most alarmist speakers, like Steffen, Karoly, Mann and so on. They are speaking from a position of intellectual eminence. Like a few others who are outspoken in their sceptical cause, they are retired. No deans are complaining to the university president about these two.

So read on.

By obligating the United States once more to the Paris agreement, and by signaling very clearly that "climate" will be central to its policies, the Biden administration has joined other governments in the crusade against a supposed "climate emergency." We use the word "crusade" advisedly, since the frenzy over climate resembles the medieval crusades against foreign infidels and home-grown heretics. There is even a children's climate crusade.

Medieval crusaders would chant 'Deus vult' (God wants it), the ultimate virtue-signalling slogan. Few leaders of medieval Europe could resist the temptation to join the crusades. The medieval elite could count on earthly rewards to add to their heavenly treasures. The enemies of God - and the little people - paid the bills.

Some climate crusaders have invoked the mandate of heaven, and others use language all too reminiscent of millenarianism. But most claim to be following a mandate of science.

We are both scientists who can attest that the research literature does not support the claim of a climate emergency. Nor will there be one. None of the lurid predictions -dangerously accelerating sea-level rise, increasingly extreme weather, more deadly forest fires, unprecedented warming, etc. - are any more accurate than the fire-and-brimstone sermons used to stoke fanaticism in medieval crusaders.

True believers assert that this emergency can be averted only by eliminating greenhouse-gas emissions. Greenhouse gases include ubiquitous water vapor, methane, nitrous oxide, and above all, carbon dioxide, a gas released when fossil fuels are burned to power transportation, generate electricity, and are used to manufacture amenities of modern life.

Greenhouse gases in the atmosphere let sunlight warm the earth's surface. But they absorb some of the heat radiation from the surface and atmosphere that would otherwise cool more efficiently by escaping directly to space. Greenhouse gases - and clouds - keep the earth's surface temperature several tens of degrees Celsius warmer than it would be without them.

So far, climate crusaders have refrained from vilifying water vapor and clouds, which make the largest contribution to greenhouse warming of the earth. Carbon dioxide, demonized as "carbon pollution," is an improbable villain. Green plants use the energy of sunlight to manufacture sugar and other organic molecules of life from carbon dioxide and water molecules. A byproduct of photosynthesis is the oxygen of our atmosphere. Each human exhales about two pounds of the "pollutant" carbon dioxide every day.

No scientist familiar with radiation transfer denies that more carbon dioxide is likely to cause some surface warming. But the warming would be small and benign. In fact, history shows that warmings of a few degrees Celsius - which extended growing seasons - have been good for humanity. The golden age of classical Roman civilization occurred during a warm period. Cooling periods, which were accompanied by barbarian invasions, famines, and plagues, have been bad. Barbara Tuchman characterizes such periods as "the calamitous 14th century" in her book, A Distant Mirror.

More carbon dioxide will certainly increase the productivity of agriculture and forestry. Over the past century, the earth has already become noticeably greener as a result of the modest increase of CO₂, from about 0.03 percent to 0.04 percent of atmospheric molecules. More CO₂ has made a significant contribution to the increased crop yields of the past 50 years, as well. The benefits to plants of more CO₂ are documented in hundreds of scientific studies.

Water vapor, and the clouds that condense from it, warm the earth's surface at least four times more than does carbon dioxide. Paleoclimate data show little correlation between CO₂ and climate, suggesting that the effects of CO₂ are, in fact, marginal. Doubling CO₂ concentrations alone should increase the earth's surface temperature by about 1 C. Climate crusaders use computer models that include clouds, convective heat transfer in the atmosphere and oceans, and other factors to claim that "positive feedbacks" increase the predicted warming to 4.5 C or more. Supposedly, the direct consequences of any change are amplified. This would violate Le Chatelier's principle that says "when a settled system is disturbed, it will adjust to diminish the change that has been made to it."