Re: scientific (in the physics/chemistry sense)
Thumbs up for AC
Basic chemistry allows us to calculate roughly how much CO2 human activity has released into the atmosphere in the last 200 years or so since the industrial revolution. Basic thermodynamics tells us how much hotter the earth will get per increased CO2 in the atmosphere (about 1 degree per 100ppm CO2), and the observed temperature increase in the last 200 years roughly matches this approximation.
Beyond that, past temperature proxies are built on layers upon layers of assumptions, adjustments and tweaks, and future climate models, however complex, are built on an incomplete understanding, and every few months a new finding comes up that contradicts the models expected outcomes.
So it's got to be clear when 'consensus' is mentioned, what the consensus is about. If the question is: "is the world warming because of human activity", the consensus of anyone with a basic grounding in chemistry and physics is "Yes", and that is a consensus that I accept.
But that doesn't mean that I can arbitrarily extend that consensus to a number of other mantras such as : temperatures now are higher than in the last 500 years, or than they EVER have been in 300 million years, temperatures will continue to increase indefinitely, positive feedback forcing will result in runaway warming, etc etc