And yet comparing a simple chemical composition of water and the effects of a particular gas on a large and very poorly understood system is somehow less tripe?
The greenhouse effect is not "poorly understood" and the link between CO2 and climate is clearly established over millions of years of geologic time. If you have trouble understanding how this is done, I recommend you read more instead of posting on hackernews. You could start here:
I never said the greenhouse effect was poorly understood, however I will for a fact state that the overall climate system of earth is relatively poorly understood. If you must insist on making wild strawman arguments, I recommend you read and understand what you read more before you start posting anywhere.
Please.