Increased atmospheric CO2 tends to close this window and cause outgoing radiation to emerge from higher, colder levels, thus warming the surface and lower atmosphere by the so called greenhouse mechanism» (joannenova.com.au)
«For example, there's no political polarization on climate change with greater understanding of the greenhouse mechanism that drives global warming,» he wrote in an email. (scientificamerican.com)
We also know that the mechanism is a greenhouse mechanism because it is simultaneously cooling the stratosphere as it warms the troposphere — only greenhouse mechanisms do this. (realclimate.org)