there was never a consensus, but they said there was... why?. without getting into the physics of co2, i'm going with the m.i.t. guy.
CO2 Science
this is a little dry but worth reading. don't forget the argument is, you think it's a lock that global warming (when there is such a thing) is manmade, and i think we don't have enough evidence to verify and conclude your claim.
The Shattered Greenhouse - How Physics Demolishes the "Greenhouse Effect".
and:
Solar activity & climate: is the sun causing global warming?
When we consider a short period, for example an 11 years period we can argue that the intensity of the solar irradiance is decreasing; however, if we consider a longer period, for example 400 years, we can see that the intensity of solar irradiance has not decreased. Some 400 years ago the solar irradiance intensity was 1365.5946 W/m^-2, while in 2000 the total solar irradiance intensity was 1366.6620 W/m^2. This year the Sun has been mostly spotless, but the solar irradiance intensity has been 1365 W/m^-2. This constitutes evidence on the existence of other solar "pulses" that we have not understood well:
The Inconstant Sun - NASA Science
Regarding the particularity of CO2 on the global warming, I don't see why to blame the CO2 of GW when its particular thermal characteristics show that the CO2 is not capable of producing any warming. The Pp of the CO2 in the atmosphere is roughly 0.00034 atm*m, wich limits the absorptivity-emissivity of the CO2 to only 0.00092 (dimensionless value), not the 0.2 given by the IPCC. The absorptivity-emissivity of CO2 is 0.00092 conduces to its total emittancy of barely 0.414 W/m^2, not the 5.35 W/m^2 given by the IPCC. If I was to blame any atmospheric gas of a GH effect, I would blame the Water Vapor, not the the coolant CO2.
the computer generated prediction models have always been weak. i would feel better if the scientists on the government dole were working to disprove this funky assertion.
it's all in the book "atlas shrugged" by ayn rand.
If CO2 has no effect, how do explain that the world would be degrees colder, if it weren't in the atmosphere? Greenhouse effect - Wikipedia, the free encyclopedia
We know CO2 absorbs infra-red radiation and even a small amount of extra heat would cause more water vapor to enter the atmosphere, where the GH effect of water would then amplify the amount of retained heat. You're right about water, but it's not the cause of AGW, but a downstream effect amplifying the effects of humanly emitted GHGs.