Most will think something like "I want to help, but if I act and no one else does it won't make a difference" or "they should pass laws to stop people from doing what causes this and after they do I'll act." To act against your values to follow others is the opposite of leadership.
Some will realize that their actions can make a difference, that they are responsible for the results of their actions -- flying, overheating or overcooling their homes, dietary choices, etc -- and they will choose to hurt others less.
One of my biggest discoveries is that making those choices improved my life. I thought they would feel like sacrifice, and they did in the short term, but in the long term they improved my life. My diet is more delicious for avoiding packaged food and eating from local farms. My life has more adventure and cultural exchange for not flying.
It's not what you stop doing, but what you replace it with.
In other words, there is no dichotomy between polluting less and improving your life.