The main problem is that these people think that they know about what they actually know nothing about... They think they can accurately measure global CO2 content, but they actually can't, since there aren't near enough uniformly spaced and simultaneously read CO2 stations in existence.
They think they can measure global sea level, but they actually can't, as there is no valid reference point to make use of.
They think they can accurately measure global temperature, but they actually can't, since there aren't near enough uniformly spaced and simultaneously read thermometers in existence.
They think they can instead get these temperature readings via satellite, but they can't, since they have no clue what the emissivity of Earth is, and to know emissivity, they first need to know temperature.
Their claims about CO2 (and its magick) regularly reject the laws of thermodynamics as well as the stefan boltzmann law, thus rejecting science.
Until they can get past those hurdles (for starters), they are simply talking out of their asses...