I think most people do believe in it and do care. However, many just can’t do that much about it. For example, switching to green electricity is quite expensive and a lot of people just cannot afford it. The same goes to people who live in remote locations, they just cannot give up their cars. This is why it is up to us, present and future scientists and engineers, to come up with more efficient and cheap ways how to generate clean energy and reduce the greenhouse emissions from things we use everyday, so that everybody could afford them.
But there is number of ways in which everybody can contribute. And even if it is something small, if enough people do it, it will still help in our efforts reducing the effects of global warming.