It is simple physics as to how CO2 works as a greenhouse gas. Seeing the clear trend of increasing CO2 in the atmosphere makes warming sort of obvious (at least to me). All of the complex second order effects (how much warming, how climate and weather patterns will react, and so on) are much more complicated and therefore less clear. Nevertheless, we are having a strong clear effect on the atmosphere which is going to warm the planet. The rest is details (though those details are getting a lot scarier, recently).
http://www.jeremyrhammond.com/wp-content/uploads/2016/03/mau...
It is simple physics as to how CO2 works as a greenhouse gas. Seeing the clear trend of increasing CO2 in the atmosphere makes warming sort of obvious (at least to me). All of the complex second order effects (how much warming, how climate and weather patterns will react, and so on) are much more complicated and therefore less clear. Nevertheless, we are having a strong clear effect on the atmosphere which is going to warm the planet. The rest is details (though those details are getting a lot scarier, recently).