You are absolutely right. This is a real issue that many want to ignore or put off on the next generation. The fact that many governments around the world recognize the problem but do little if nothing at all to remedy the situation is disturbing to say the least. The United States government being one of the biggest obstacles. My answers may seem easy to say, but if a real change in not only policy but the way humanity lives as a whole could occur, then real appreciable improvement in our environment can happen. Until we discover or terraform another inhabitable planet, [most likely 150-200 years from now at best] this is the only place we have. I will begin with 3 major things, then get to the simpler things.
1. A worldwide organization such as the UN should mandate that all countries observe a non-threatening environmental policy. Again, easier said than done I realize, especially since the US would have to be a major proponent, but maybe it could be a reduction of 10 or 15% of current global greenhouse gases for instance.
2. The technology exists today to make all internal combustion engines of automobiles out of hybrids. This is a good start, however completely getting rid of fuel combustion engines has the main obstacle of Greed. Try to convince the powers that be of say, OPEC, that their pockets will be reduced by 50% and see what happens. They would not be too happy. Hence, an alternative clean fuel must be found. Hydrogen fuel engines perhaps??
3. Smart Infrastructure. Creating a smarter mass transportation system throughout the country such that the average person would actually use it. Yes, a lot of money involved but how much do we squander on useless things such as wars etc.
4. Obviously at home the first thing that comes to mind is: USE LESS. We, especially in the US, take forgranted that we have an abundance of power where countries like the Phillipines have blackouts constantly. We need to stop being power hogs and learn to sacrifice more. Turn off all your lights when not using them. In the summer, its great to have AC but reduce it a bit, sweat a bit...hell we could all stand to lose a little weight.
5. Plant an evergreen tree in your yard if possible. The exchange of carbon dioxide and oxygen will help.
6. Though we all love the independence our cars give us, once a week or maybe more use mass transportation.
7. At work, actually turn your computer off. Many people leave their computers on when they go home. That energy is coming from somewhere and that somewhere is pumping poison into our lives.
No matter what we do, it will take time to reverse the environmental effects that mankind has inflicted. However, if we do not start now, one day there may not be a mankind.