What data is used in computer models run by climate scientists, and what exactly do the models tell us?

1) Some people disagree with the IPCC findings. What are the motivations of these people and how has this criticism strengthened the science?
Your response must be at least 200 words in length. All sources used, including the textbook, must be referenced. Paraphrased and/or quoted materials must have accompanying in-text and reference citations in APA format.
(2) 
What data is used in computer models run by climate scientists, and what exactly do the models tell us?
Your response must be at least 200 words in length. All sources used, including the textbook, must be referenced. Paraphrased and/or quoted materials must have accompanying in-text and reference citations in APA format.
(3) 
Do you think carbon emissions should be taxed by governments in order to manage carbon release? Why, or why not?