Over the last several years I have worked to understand the origins of climate change. My conclusion is that the temperature at the surface of the Earth is affected by the presence or absence of clouds that reflect short wave energy from the sun back into space. The presence and density of cloud is a simple function of the temperature of the troposphere that is affected by the ingress of ozone, a potent greenhouse gas that absorbs long wave infrared radiation from the Earth. Ozone is injected into the troposphere in high latitudes due to the coupling of the stratosphere and the troposphere that occurs most strongly in winter in polar regions. It is carried towards the equator by the counter westerlies producing a tell tale pattern of sea surface temperature change. The amount of ozone injected into the troposphere is a function of the strength of the polar night jet that introduces nitrogen oxides from the mesosphere into the stratosphere. Nitrogen oxides erode ozone in the stratosphere. The primary control of the ozone content of the stratosphere (and its temperature) is via the poles where the night jet varies in its activity with atmospheric pressure. Initially atmospheric pressure changes according to solar activity. Atmospheric processes then amplify the change.
You can see how I have come to that conclusion by downloading the paper that is available here:
It is my conclusion that human activity has made little or no contribution the increase in the temperature of the lower troposphere and the warming that has been experienced is localized, temporally uneven and reversible.