Talked to one global warming scientist (my wife) about it briefly. Will consult a bigger wig soon if I get the chance. But based on that brief discussion with my wife:

Nothing new here and nothing that is supported. First off, my own question just as a scientist myself and a semi-journalist: what is this guy's qualifications. He says he did "carbon accounting, building models for the Australian Greenhouse Office..." but that isn't necessarily the same as being a scientist. My wife, who does climate modeling, though it isn't the main part of her research, didn't think a model of what the guy claimed he modeled would be very reliable. What is his doctorate in? He sounds like a computer guy, which means his grasp of the physics may be weak. That is not an accusation, but a question. He is not someone who is well known in the field from what I have been able to acertain. But my brief exploration may not have been extensive enough. So my first question is why should this guy's word be taken over top scientists who focus not on carbon accounting (which may not involve much actual climatology) but on actual physics and atmospheric sciences?

Now to Evans' four points.

1. He makes an unsupported statement here that is the basis of this point and probably the second point. Claiming that there is one definitive "signature" to look at is a big leap and not widely accepted, yet it is the basis of his claim. He needs to support this assertion before it can be taken seriously. Specifically, anthropogenic global warming does NOT require the formation of "a hot spot about 10km up in the atmosphere over the tropics" according to my wife. She would be very interested in Evans' evidence for this, but you might notice he asserts it unsupported. That is unscientific. I do intend to try and see if anyone else out there thinks this is a supported hypothesis, but so far he seems to state it from nothing. My guess is that it is one of several possible hypotheses and he is picking it without letting on that it isn't definitive, but I'd need to look into it more.

2. This is a bit silly. The physics of how pretty much every atmospheric gas interacts with solar radiation and affects temperature is well worked out. He admits that the physics is known and he admits that global warming is happening. What he fails to say is that once you have the physics you can observe what is actually happening and see if it fits the physics. In this case it does. I have always said that global warming isn't really a hypothesis so much as proof of principle. We know from physics that atmospheric carbon dioxide will trap heat. We know that carbon dioxide is rising and that temperature is rising in pace with the carbon dioxide rise. This fits the prediction quite well. No one disputes the physics and no one disputes that what is observed fits the physical theory. This would be considered standard scientific evidence in support of the anthropogenic global warming hypothesis. A prediction is made based on physics and the observed changes match well with what is predicted. Evans suggests that something more is needed. In my field you can do controlled experiments. In earth's climate we have physics and real observation (and comparisons with Mars and Venus) but of course we can't have the control where we observe earth without the carbon emissions. Yet that seems to be what he wants. Basically the realities of the field are that you have the physics and you have observation of what is really happening and in this case the observation fist precisely what you would predict from physics and supports the anthropogenic global warming hypothesis.

3. My wife laughed at this. Simply put the "urban heat island" thing is a red herring. Climatologists have been well aware of this and have taken it into account for years now. Even I know this. The surface measurements are NOT corrupted by the heat islands. The heat islands are well understood and taken into account. As to satellite data, my wife wasn't sure what the most up to date stuff is, so she wasn't ready to comment on Evans' claims, but I am thinking back to some scientific papers that came out I think two years ago that reconciled the satellite data with the surface data. Basically the satellite data combined two layers of the atmosphere, one of which is cooler than the other naturally. This masked warming. Once a way was found to separate the data from the two layers the atmospheric data from satellites fit perfectly with surface temperature measurements. I think I cover this here (buried somewhere in the middle). I am not sure if this is the satellite data Evans is referring to, though, since he isn't really clear on what part of the atmosphere he is talking about. I would like to follow up more on this if I get the chance.

4. ice cores??? My wife really laughed at this claim. No one...NO ONE claims to be able to use ice core data to pinpoint cause and effect within an 800 year time frame. Current warming of course is not judged by ice core measurements, but the half a million year record that provides context does depend on ice cores, of course. Ice core data is not precise enough to make the claim Evans does about cause and effect. No one can say anything about which is cause and which is effect from ice cores, so his fourth point is completely invalid. He is probably just looking at a graph without taking into account the statistical error, so he is assuming a precision of the timing of events that is misleading him.

So that is a brief comment based mostly on my wife's reading of the article (and she does study this stuff) and my own more limited knowlege. I will try to look more in dept at some point if I can.

Also, until I can talk with someone else I want to consult, I can refer you to here for further refutaion of Evans in general.