Venus is a very different planet with a day longer than it's year resulting in hypervelocity winds distributing the heat and spreading out a constant opaque cloud layer which coincidentally ends at the altitude where atmospheric pressure and temperatures are Earthlike. It's important to note that regardless of the density of CO2 below the cloud layer, only 30% of heat radiation could pass through the cloud layer so the density may have nothing to do with it except is sustaining the cloud layer. As to the Earthlike conditions at the 65 km altitude, by earthlike temperatures, they mean 50 Celsius while Earth's average surface temperature is about 15 Celsius. The 65 km altitude is not an indication that the CO2 concentration doesn't have an effect.

Linlyons,

Kano is at least partially correct. The warmer mentality has density causing absolutely no warming.

Now I am not sure how much thickness of the atmosphere contributes in comparison with greenhouse effect, but I am sure that thickness does play a role.

This is not the only assumption made that would lead to overestimating the climate sensitivity. Is it any wonder why >95% of the current climate models are overestimating?

In fact, you should look at the STRONG anti-AGW sentiment. Are you surprised?

You have scientists overestimating consistently.

You have the media taking the scientists work and exaggerating to the point of absurdity.

You have the seemingly sole answer to the "problem" as a TAX during a period where the economy is struggling and people are already overly burdened with local, state, federal and social taxes.

Most of us have read the argument.

It goes something like this:

As the density of CO2 increases, it becomes less effective.

The contention comes with the understanding of the decrease in effectiveness.

Quite clearly, looking at Venus, much more CO2 induces much more warming.

That would indicate that the skeptic's contention that we are already reaching the limit of CO2's effectiveness is wrong.

"The main atmospheric gases (of Venus) are carbon dioxide and nitrogen. Other chemical compounds are present only in trace amounts."

So, the answer to your question is, yes, we have looked at the argument.

And we find that it really doesn't apply.

You mean true alarmist or people who are concerned about CO2 emissions.

I doubt that alarmist have as they would not stay as alarmists for very long, the evidence against CAGW is quite persuasive.

Your link about venus actually proves CO2 is not effective for warming, at the same atmospheric pressure as Earth, with 95% CO2, the temperatures are roughly the same, meaning it is pressure that makes Venus hot not CO2, and considering Venus is closer to the sun, that makes CO2 even less important.

Apparently not and there is not enough scientific evidence to initiate such a question. My goodness! Just look at the amount of CO2. 0.04% is not enough to control anything. It would be equivalent to the tail wagging the dog.

So exactly who is an alarmist?

What level of concern is so unwarranted to be labeled "alarmist"?

Define limits.