If people would make rational choices based on knowledge there would be no obesity (you have amount of calories on product labels).
People are aware that catastrophe is coming but they are in denial. It's just better to not think about it, like with death, you know it will come but you don't think about it, just carry with your life. And I can see the same exact thing with global warming when I talk to different people. It's better to think that I can't do nothing than think I can do something but I will need to change my style of life.
There are things one can do to live longer but they require sacrifices, do not eat bad stuff, exercise etc. For a lot of people price is too high. The problem is that in case of global warming those people are making choices for other people also.
There is no political will to change things, as every politician knows that the costs for that would be too high today. So that's why they think it's better to postpone this decisions, automatically making the cost a lot higher. There is also believe that someone will figure out a way to stop global warming in his basement and will save the humanity from itself. The problem is a lot more complex than just CO2, it's about the current economic model of the modern society in which we live. Constant growth and resource exploitation are not sustainable for long term.