Here is the problem with arguing against AGW.
1) CO2 has gone up due to human's burning stuff.
2) CO2 absorbs IR and behaves as a GHG.
3) Temperature has gone up in the same time period.
Given these facts, it is very simple to claim that there is a causal relationship. You can't easily say, it ain't a problem, given the above facts. I don't think this is a scam. It is just that the above three things seem so obviously related that it is hard for people (scientists) to believe otherwise. And, doomsday is an interesting thing to investigate.
But, it is getting pretty clear that if you happen to have alternate theories, no matter how compelling, it is almost impossible to get published.
JMC Said:
3)Today both CO2 levels are at their highest levels in 10,000 years, and we've been getting the warmest summers in centuries.
Not sure what he was trying to say, but CO2 seems to be higher than it has been in many hundreds of thousands of years. The fact that temperatures are only higher than they have been in centuries rather than hundreds of thousands of years seems to indicate a lack of cause rather than cause. This and your two other points are very disputed, JMC. You should look this stuff up.
The corrected Mann hockey stick:
Another proxy study, sans tree ring data, clearly showing it has been warmer pretty recently.
So, here is the thing. Clearly, temperatures have gone up and down on scales and time frames comparable to our recent warming according to the above diagram. If they have in the past, then why do we assume it is CO2 now that is doing it? If it must be CO2 now, then what was it in the past? If it wasn't CO2 in the past, then why do we think it has to be CO2 now?
tomclark said this:
And global temperatures have increased dramatically over the last 100 years in a way which cannot be explained except as GWG effects.
But temperatures have done this in the past. Again, if it wasn't CO2 then, why assume it must be CO2 now? There has to be some other thing that can cause these temperature differences! Look at the proxy data.
I assume that anyone willing to talk about this topic understands the radiation balance of the planet, right? There is a lot of energy coming in as visible light. There is a lot of energy going out as IR. The main argument about GW being caused by excess CO2 demands that the amount of outgoing IR is reduced (actually delayed) by fractional changes in CO2. Tiny changes in CO2 cause tiny changes in the energy balance. Enough that we notice, but still tiny on the scale of the total amount of energy going out. The point being that it doesn't take much change in CO2 to change the temperature of the atmosphere. At least that is the argument.
Well, if this is true, then it should also be true that tiny changes in the amount of energy coming in would cause enough temperature difference for us to notice. Remember that visible light coming in is partially reflected by the earth and it's atmosphere. This is refered to as the albedo of the planet. Small changes in the albedo can cause tiny but still significant changes to the incoming radiation as reflected light. If there is less reflection, there is more energy coming in. More reflection, less energy coming in. Surprisingly, it takes only fractional changes to the major contributor to the earths albedo to do explain 20th century warming, and probably some past periods of warming as well. A 1% change in cloud cover would do it for example.
Heck, if that were true, it could not only explain modern warming, but small scale warmings of the past as well. Is it possible that clouds cause this warming?
Well, at least one man thinks so. Reference this info from Roy Spencer if you want to see something very interesting. He seems to be able to show that the Pacific Decadal Oscillation is responsible for MOST of the 20th century warming, including the cooling between the 40's and 70's, is probably due to changes in the Earth's albedo.
http://www.weatherquestions.com/Global- ... al-PDO.htm
Fluctuations of temperatures now and fluctuations of temperatures in our recent past (2000 years) explained by a simple hypothosis on a natural cycle. The PDO causes changes in our cloud cover that allow more or less energy in. Here is his take on the relationship:
And, speaking of people who can't get published, how about this 30 year NASA scientist, Miskolczi, who has a rather interesting theory regarding the saturation of the greenhouse effect. He updates some dubious math of the past in a recent paper. Of course to publish he had to leave NASA and publish in his native Hungary.
http://www.met.hu/idojaras/IDOJARAS_vol111_No1_01.pdf
Coincidentally, both Miskolczi and Spencer say that there is likely some warming from CO2, and, coincidentally, they both put it around 0.2 degrees C for the last 100 years, both are saying that this is not a big deal, and both are saying that the models are fundamentally flawed, Spencer because of the lack of clouds being taken into account, and Miskolczi because of fundamental mistakes in the math.
Both are able to show strong coorelations to real data.
AGW is by no way proved or a concensis. Getting published with opposing positions is nearly impossible.
It is not a scam. It is just a natural progression of a flawed assumption based around a few seemingly compelling facts. The boulder is rolling. It will be hard to stop.
Just thought I would chime in.
