Interview met William Happer (Princeton): klimaatsceptische consensus. Deel II

Dit is het tweede deel over het interview met William Happer, gepubliceerd op de website van ‘The Best Schools’. Het eerste deel is hier te vinden.

Allereerst wordt Happer gevraagd wat zijn mening is over de officiële opvatting van het VN-klimaatpanel (IPCC).

The IPCC’s official position may be summarized as making four claims:

• global warming is a well-established fact;

• it is anthropogenic;

• it is a major problem for humanity; and

• concerted global governmental action is required to combat it.

William Happer:

Yes, CO2 levels have been increasing, at about two parts per million (ppm) per year in recent years. Yes, CO2 is a “greenhouse gas.” That is, it is partially opaque to the thermal, infrared radiation of the earth’s surface, but transparent to most sunlight. … [The statement] the earth’s atmosphere must become warmer” is not very well posed. As you know the atmosphere, does not have a single temperature. …

The air temperature continues to decrease with altitude until you reach the “tropopause,” about 11 km of altitude over much of the continental USA. …

The troposphere — the first 11 km of air — is quite different from the stratosphere. Close to the earth’s surface, much of the heat transfer is by convection of moist air and not by radiation, where more CO2 could make a direct difference. More CO2 will probably warm the troposphere and the earth’s surface. But the magnitude of the warming is very poorly known. My educated guess is that doubling CO2 concentrations will warm the surface by about 1° C and will warm the middle troposphere by about 1.2° C. These are numbers that you calculate from the direct effects of more CO2. The much higher “equilibrium climate sensitivities” quoted by the IPCC, say 3° C for doubling CO2, come from assuming that the relatively small direct temperature increase from more CO2 is greatly amplified by the changes in the properties of water vapor and clouds. There is less observational support with each passing year for this “positive feedback” on the direct warming from CO2.

Over de klimaatgevoeligheid bestaat dus verschil van mening, niet alleen tussen AGW-protagonisten (AGW = ‘Anthropogenic Global Warming’) enerzijds en -antagonisten anderzijds, maar ook binnen beide kampen. De meeste klimatologen zijn niet in staat om een zelfstandig oordeel te vellen over de berekening van de klimaatgevoeligheid. Het is een heel ingewikkelde materie waarvoor specialistische kennis is vereist. Zij volgen hun collega’s die dat wèl kunnen. Wereldwijd beschikken slechts enkele tientallen wetenschappers over die kennis. Maar zij zijn het (nog) niet met elkaar eens. Aan AGW-zijde lopen de schattingen uiteen van zo’n 1,5 – 6 graden Celsius – aan klimaatsceptische zijde van ongeveer 0 – 1,2 graden Celsius.

Vervolgens gaat het interview in op de opvattingen van William Happer over de ‘feiten’ waarover volgens de AGW-adepten geen verschil van mening zou bestaan.

William Happer:

Global warming is a well-established fact.

This statement is only half true. A more correct statement would be “global warming and global cooling are both well-established facts.” The earth is almost always warming or cooling. Since the year 1800, the earth has warmed by about 1° C, with much of the warming taking place before much increase of atmospheric CO2. There was a quite substantial cooling from about 1940 to 1975. There has been almost no warming for the past 20 years when the CO2 levels have increased most rapidly. The same alternation of warming and cooling has characterized the earth’s climate for all of geological history.

It is anthropogenic.

No, most of the warming has probably been due to natural causes. But much of the increase in CO2, from around 280 ppm in the year 1800 to about 400 ppm in 2015, is probably anthropogenic, although the warming oceans and land have also released some CO2. The warming of urban areas has correlated well with increasing CO2. This is the well-known urban heat-island effect of expanding cities. But it is not increasing CO2 that causes urban warming; rather, it is the replacement of green fields and forests, with their transpirational cooling, by roads and buildings which do not transpire water vapor. ….

Potent natural influences on climate include relatively short-period phenomena changes in ocean conditions like El Niño and longer-period changes like the Pacific Decadal Oscillation, or the North Atlantic Oscillation. Large volcanic eruptions are known to cool the climate for a few years. There is growing evidence that changes in solar activity somehow affect the climate, and there are probably many other influences that we have not yet recognized.

Some small fraction of the 1° C warming during the past two centuries must have been due to increasing CO2, which is indeed a greenhouse gas. ….

[…] the feedback-free warming should have been ΔT = 0.51° C, or about half of the observed warming. The other half of the warming would have been due to natural causes, perhaps related to the recovery of the earth from the “Little Ice Age,” which we will discuss a bit more below.

The favored IPCC equilibrium sensitivity is S = 3° C, about three times larger than the feedback-free value of S = 1° C. So, the CO2-induced warming from IPCC models should have been three times larger, … , substantially more than the observed warming.

To cope with this embarrassing overestimate, establishment models assume that much of the warming has been cancelled by aerosol cooling — for example, by small sulfate particulates from the combustion of high-sulfur coal and oil. … But the devil is in the details, and many scientists who have looked carefully at the physics regard the aerosol corrections as largely a fudge factor, invoked by the global warming establishment to avoid admitting the equilibrium temperature rise from doubling CO2 is much less than S = 3° C.

It is a major problem for humanity.

Quite the contrary, more CO2 will be a benefit to humanity. The predicted warming from more CO2 is grossly exaggerated. The equilibrium warming from doubling CO2 is not going to be 3° C, which might marginally be considered a problem, but closer to 1° C, which will be beneficial. ….

More CO2 greatly increases the efficiency of photosynthesis in plants and makes land plants more drought-resistant. So, the net result of more CO2 will be strongly beneficial for humanity.

Concerted global governmental action is required to combat it.

In view of the comments above, this is nonsense. Government actions to combat the non-existent problem have blighted the landscape with windmills and solar farms. They have driven up the price of electricity, which has disproportionately harmed the poorest segments of society. Government actions have corrupted science, which has been flooded by money to produce politically correct results. It is time for governments to finally admit the truth about global warming. Warming is not the problem. Government action is the problem.

Aldus William Happer.

Lees verder hier.

In een volgende aflevering zal worden ingegaan op klimaatmodellen, de betrouwbaarheid en aanpassingen van temperatuurdata, de hiatus enz.

Inmiddels is William Happer ook bij Donald Trump op bezoek geweest. Zie hier.

Voor mijn eerdere bijdragen over klimaat en aanverwante zaken zie hier, hier, hier, hier en hier.