One subject at a time, I guess.
Environment... I am not pointing the finger at just you, and I am far from a tree-hugger. But the "hundred years from now" cop-out is not only selfish, but it's denial. You are wrong on the timeline and I suggest that you do the research if you are undr 60yrs old.
The environment is rapidly changing due to the greenhouse emissions we put out. There are more tsunamis, hurricanes, tornadoes, etc. than ever and they're coming faster and more powerful.
True, if you buy a hybrid, you're spending a lot more money. But if you drive it properly and keep driving that hybrid, you will save money in the long run on fuel alone, during the warranty period alone you come out even. But the Hybrids will get cheaper as time goes on. You could just drive a smaller car too, I don't have a hybrid, but my Sentra gets around 33mpg. That's better than most cars out there, even better than some hybrids(i.e. hybrid SUV's)
It's also true that cars aren't the only solution, this goes as far as building more nuclear power plants to reduce the use of coal plants. Using more windmills and dams would help too, although if you're concerned about the environment, you might cry over the habitat that gets ruined/drastically changed by the dams.
Your are absolutely correct about the trees though. They take CO2 out of the air but that's not the only greenhouse gas that causes the global warming that's happening at an exponential rate. Tree's don't cake care of the other carbon emissions, unspent fuel, and other gasses.
5,000lb cars/SUV's
Although it WAS typical for cars to weigh a lot, but welcome to planet earth. Fuel is getting more expensive by the day, cars are getting smaller and cheaper, and it's not typical for the average family to own cars that weigh over 3000 pounds. You can't fill up that 20gal tank for $5 anymore. My 12gal tank costs $35 each time I go to the pump. It is now the heavy vehicles that are the danger on the road. So to help ensure the driver's safety, we have things like crumple zones, ABS, seatbelts, airbags, electronic stability control, and more to come. But you are wrong to say that a person is selfish to buy a smaller car or a hybrid. Maybe they're trying to save some money, maybe they're trying to do thier little part in helping the environment. But it's a good thing either way, not just for the individual.
New VS Old, people and cars.
Newer cars are safer, faster, more fuel efficient, cheaper to repair, and have more convenient features than older cars. Your Oldsmobile, while a nice car, was definitely more sturdy than that crappy civic, but if you were on the tail end of a HUM-V or an 18-wheeler, you would have been the one hurting. So that's just a matter of perspective.
As far as people go, ignorance exists in everybody in one sense or another, regardless of age. But as people age, they either get hard and set in thier ways, or they become more wise and conscious of life in general. This does come in a mix, but I get the impression that you're the more of the former and less of the latter.
The worst assumption a person can make regarding age is to think that young people are less knowledgable or more ignorant simply because they haven't been around as long as you. I am not referring to the 14yr old know-it-all, but people like me. I am a nuclear reactor operator and just shy of my BSAST in nuclear engineering, yet I am only 22. Do not take any offense to that. I am not trying to say that you are not educated or that you are stupid. You seem rather intelligent, in fact. I am simply stating that times are changing and the human race needs to adapt on all levels. That includes environmental, political, and the way we act as individuals.
lastly, liscencing.
I do think that there need to be more classes of vehicles, by weight and size specifically. Along with that, I believe that the different classes of vehicles should require an appropriate liscence. This is because of today's 'norm' for vehicles is significantly different than what it was even ten years ago. I do remember when gas was under $1/gal but I can't say that I remember the prices you say you've seen. That's obviously because I wasn't alive then.
Please respond with something interesting. I think that you would be a fun person to debate with.