JoNova

A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).


The Skeptics Handbook

Think it has been debunked? See here.

The Skeptics Handbook II

Climate Money Paper


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Australian Environment Conference Oct 20 2012


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GoldNerds

The nerds have the numbers on precious metals investments on the ASX



A discussion of the Slaying the Sky Dragon science: Is the Greenhouse Effect a Sky Dragon Myth?

 ”Skeptics” are described as if they are one small block of  fringe extremists, but not only is half the population skeptical in some sense, in this debate I am not on either extreme, but a centrist, smack in the middle. On the one hand, alarmists are convinced the climate is headed for a catastrophe, and on the other some people are convinced there is no greenhouse effect at all. Wes Allen, sits in the middle with me, and he’s been engaged in an intense debate with people on both ends of the spectrum. After a scorching critique of Tim Flannery’s work, he has swung his attention the other way. Here is his synopsis of the Slayers book, for discussion, and I’m sure it will generate a long passionate defence and debate, just as previous posts on this topic have. (eg: Why greenhouse gas warming doesn’t break the second law of thermodynamics and So what is the Second Darn Law?). I know the Slayers are keen to discuss their ideas. I’m hopeful people can remain polite, as that’s where progress may be made… many thanks to Wes here who has done a diligent write up, and has gone to great [...]

Monckton on blackbody radiation

I wrote to Christopher Monckton a while back to ask him about a post Blackbody – the key error in climate science, and bless his soul, he whipped off a letter with his detailed answer and wrote it all back to me, saying that other people were asking him about that too. It’s a shame to keep it hidden and high time I brought it out. Usually this topic generates quite a discussion. Though, warning (!) it contains equations, and primarily discusses the physics of blackbody radiation from Earth. It is essentially a debate about the core physics among a few skeptics. The most curious thing being that this time — this blog is on the mainstream end of opinions. (Yes, I think there is a greenhouse effect as I explained here and here).

Huffman asserts there is no measureable greenhouse effect on Venus and Earth and that the temperatures of both planets is determined by their distance to the sun. (Michael Hammer responded to that with an explanation of why we know There is a Greenhouse Effect on Venus). My unsophisticated thought was that if distance explained it all, then ergo, albedo would have no effect at all [...]

There is a Greenhouse Effect on Venus

I‘m peppered with emails asking me if articles like this one (which claims there is no Greenhouse Effect at all on Venus) could be right.

Michael Hammer has some 20 patents in spectroscopy, and he explains why the Greenhouse Effect — where CO2 and other gases absorb and emit infra red — is very real, and backed by empirical evidence. The calculations using the Stefan-Boltzmann Law on the atmosphere of Earth and Venus, argue that the Greenhouse Effect is not-detectable. But not-detectable (by that method) does not “prove” the effect is zero. Other methods — like satellite observations of Earth’s atmosphere, and countless lab experiments, tell us that the Greenhouse Effect is real. (The Stefan-Boltzmann Law is used to create the first graph below). Huffman’s calculations suggest other factors are more important than greenhouse gases (with which we heartily agree) and that Hansen et al were barking up the wrong tree by pretending that Venus “shows” us anything much about the Greenhouse Effect. (Indeed, the IPCC mention “Venus” in their first Assessment Report back in 1990 as one of the three key reasons.)

So here in middle-of-the-road centrist land, the people who claim Earth could become more like Venus are [...]

So what is the Second Darn Law?

With nearly 500 comments on the thread on the Second Law of Thermodynamics there is obviously a need for people to discuss the basic greenhouse theory. Here’s a new thread on that theme.

So what is the Second Darn Law?

From NASA:

But there are variations

As with all these Laws of science there is no exact wording, because There Is No God Who Issues Science Decrees*.  What we have are human efforts to best explain the world around us. Note that the two well known versions of the Second Law both contain the phrase “whose sole result”, meaning that heat transfer can certainly move from a colder to a warmer body if there is some other compensating movement where more heat is transferred from a hotter body to a colder one. Voila… whatever heat transfer goes from greenhouse gases to the Earth is more than countered by the heat moving from the Sun to Earth and on to space. Greenhouse gases can heat the Earth as long as the entropy of the whole system increases.

[...]

Greenhouse Gas warming doesn’t break the second law — Comments Overflow

Here are the first 500 comments on this thread (plus some orphans*). To make a new comment go to the original page.

Why greenhouse gas warming doesn’t break the second law of thermodynamics

*Orphan comments were recent ones attached to an older comment. When the older comment was moved to this thread they lost their position, and needed to be moved here. Sorry for any disruption to the flow. – Jo

Why greenhouse gas warming doesn’t break the second law of thermodynamics

This is generating many comments, see below for an update!

Behind the scenes some skeptics are suggesting that CO2 can’t warm us because the atmosphere is colder than the planet, and  it would break the 2nd Law of Thermodynamics (see Postma*, for example, p 6 – 7). I disagree. The 2nd Law of Thermodynamics applies to net flows of heat, not to each individual photon, and it does not prevent some heat flowing from a cooler body to a warm one.

Imagine three blocks of metal side by side. They are 11°C, 10°C, and 9°C. Think about what happens to the photons coming off the atoms in the middle of the medium temperature block between the other two. If heat never flows from cooler blocks to warmer blocks, all those photons have to go “right“, and not ever go “left”, because they “know” that way is towards a cooler block? (How would they?!)

The photons go both ways (actually every way, in 3D). There are more coming from the 11°C block to the 10°C block, sure, but the the 10°C block is sending ‘em back to the 11°C block too. So heat is flowing from cold to hot. It happens [...]