[lewislynn]

If there is no greenhous effect there also can’t be a greenhouse gas.

[NicknamedBob]

"If there is no greenhous effect there also can’t be a greenhouse gas."

That's an unwarranted conclusion. The primary greenhouse gas is water vapor, which affects temperature in ways both positive and negative, in the lower atmosphere as well as the upper atmosphere.

The real question is not whether carbon dioxide is increasing, as it clearly must, but whether its greenhouse gas function is totally or predominantly masked by the overwhelming presence of water vapor.

[slowhandluke]

If there is no greenhouse effect there also can’t be a greenhouse gas.

Not quite. The AGW claim was that we faced the possibility of a run-away greenhouse effect due to a positive feedback loop, caused by C02. The anti-AGW claim is that this claim was wrong on several counts.

1. CO2 is a minor player
2. C02 greenhouse effect has an upper limit, more CO2 than this limit has no further effect - and we've reached the limit.
3. There was no proof behind the idea of a run-away greenhouse effect, which would seem to violate rules of black-body radiation.

Lindzer of MIT published a recent paper proving that there is no positive feedback. The AGW claim is that the warmer it gets, and the higher the CO2, the less heat will be emitted from the upper layers of the atmosphere. The satellite record proves otherwise.

So, there are greenhouse gases, but no run-away greenhouse effect and so no catastrophic warming.