David Evans: AGWer bekeerd tot klimaatscepticus

Evans is a mathematician and engineer, with six university degrees including a PhD from Stanford University in electrical engineering. The area of human endeavor with the most experience and sophistication in dealing with feedbacks and analyzing complex systems is electrical engineering, and the most crucial and disputed aspects of understanding the climate system are the feedbacks. The evidence supporting the idea that CO2 emissions were the main cause of global warming reversed itself from 1998 to 2006, causing Evans to move from being a warmist to a skeptic.

The debate about global warming has reached ridiculous proportions and is full of micro thin half-truths and misunderstandings. I am a scientist who was on the carbon gravy train, understands the evidence, was once an alarmist, but am now a skeptic. Watching this issue unfold has been amusing but, lately, worrying. This issue is tearing society apart, making fools and liars out of our politicians.

The whole idea that carbon dioxide is the main cause of the recent global warming is based on a guess that was proved false by empirical evidence during the 1990s. But the gravy train was too big, with too many jobs, industries, trading profits, political careers, and the possibility of world government and total control riding on the outcome. So rather than admit they were wrong, the governments, and their tame climate scientists, now cheat and lie outrageously to maintain the fiction that carbon dioxide is a dangerous pollutant.

Let’s be perfectly clear. Carbon dioxide is a greenhouse gas, and other things being equal, the more carbon dioxide in the air, the warmer the planet. Every bit of carbon dioxide that we emit warms the planet. But the issue is not whether carbon dioxide warms the planet, but how much. Most scientists, on both sides, also agree on how much a given increase in the level of carbon dioxide raises the planet’s temperature, if just the extra carbon dioxide is considered. These calculations come from laboratory experiments; the basic physics have been well known for a century.

The disagreement comes about what happens next. The planet reacts to that extra carbon dioxide, which changes everything. Most critically, the extra warmth causes more water to evaporate from the oceans. But does the water hang around and increase the height of moist air in the atmosphere, or does it simply create more clouds and rain? Back in 1980, when the carbon dioxide theory started, no one knew. The alarmists guessed that it would increase the height of moist air around the planet, which would warm the planet even further, because the moist air is also a greenhouse gas. This is the core idea of every official climate model: for each bit of warming due to carbon dioxide, they claim it ends up causing three bits of warming due to the extra moist air. The climate models amplify the carbon dioxide warming by a factor of three – so two thirds of their projected warming is due to extra moist air (and other factors), only one third is due to extra carbon dioxide.

I’ll bet you didn’t know that. Hardly anyone in the public does, but it’s the core of the issue. All the disagreements, lies, and misunderstanding spring from this. The alarmist case is based on this guess about moisture in the atmosphere, and there is simply no evidence for the amplification that is at the core of their alarmism. Which is why the alarmists keep so quiet about it and you’ve never heard of it before. And it tells you what a poor job the media have done in covering this issue.

Weather balloons had been measuring the atmosphere since the 1960s, many thousands of them every year. The climate models all predict that as the planet warms, a hot-spot of moist air will develop over the tropics about 10km up, as the layer of moist air expands upwards into the cool dry air above. During the warming of the late 1970s, 80s, and 90s, the weather balloons found no hot-spot. None at all. Not even a small one. This evidence proves that the climate models are fundamentally flawed, that they greatly overestimate the temperature increases due to carbon dioxide. Etc. etc.