How do we know more CO2 is causing warming?

Easy, just measure A and claim you have measured B.

From the Motherlode of Shite, they make the obligatory and wrong assumption that sea level temp’s should be the same as cloud temps (it is the clouds that absorb most of the arriving sunlight; not the sea level surface – this is the basis for the correct explanation of the Greenhouse Effect because that is what we are measuring – difference between cloud temp and sea level air temp = 33 degrees) and then crack on with the flimsiest of evidence:

The temperatures are going up, just like the theory predicted. But where’s the connection with CO2, or other greenhouse gases like methane, ozone or nitrous oxide?

This time, we see that during the period when temperatures increased the most, emissions of upward radiation have decreased through radiative trapping at exactly the same wavenumbers as they increased for downward radiation. The same greenhouse gases are identified: CO2, methane, ozone etc.

OK, CO2 tends to block and/ore re-radiate infra red at about 14 nanometers (= about 700/cm), there’s less going to space and more hitting the ground, clever scientists have measured it and who am I to disbelieve them?

But WTF does that have to do with temperatures?

Wien’s Displacement Law tells us the relationship between an objects temperature and peak frequency; the object absorbing that frequency can’t get any warmer than the apparent* temperature of the emitting object. 14 nanometers = apparent temperature approx 200 K = minus 73 C.

* I say apparent because the actual average temp of the CO2 is about 250K, but it emits radiation as if it were only 200K, so can’t warm anything up to more than 200 K.

Even if CO2 emitted radiation at the shorter peak wavelength we would expect from an object that is approx. 250K, that wouldn’t be able to warm an object (sea level surface) either, as sea level surface is warmer than that anyway. If you have a forge furnace burning coal at 2,000C, you can’t use it to warm anything up warmer than 2,000 C, that ain’t happening.