Since to me (and many
scientists, although some wanted a lot more corroborative evidence, which they've also gotten) it makes absolutely no sense to presume that the earth would just go about its merry way and keep the climate nice and relatively stable for us (though this rare actual climate
scientist pseudo skeptic seems to think it would, based upon some
non scientific belief — see second half of this piece), when the earth changes climate easily as it is, climate is ultimately an expression of energy, it is stabilized (right now) by the oceans and ice sheets, and increasing the number of long term thermal radiation / heat energy absorbing and re radiating molecules to levels not seen on earth in several million years would add an enormous influx of energy to the lower atmosphere earth system, which would mildly warm the air and increasingly transfer energy to the earth over time, which in turn would start to alter those stabilizing systems (and which, with increasing ocean energy retention and accelerating polar ice sheet melting at both ends of the globe, is exactly what we've been seeing) and start to reinforce the same process until a new stases would be reached well after the
atmospheric levels of ghg has stabilized.
«Because of the system's complexity and
non — linearity, without a quite detailed understanding of the system,
scientists can not provide useful guidance regarding the impact on climate of increases in
atmospheric ghg concentration.»