Is it really helping?

Awareness about climate change is, while not necessarily at an all-time high (thank you, "climate change deniers", for helping to ruin my state), it's certainly in a lot of people's minds. And I think a lot of people are working in little bits to try to help out. At the very least, it makes economic sense for people to drive less, turn off lights when no one's in a room, and use more efficient appliances, etc. But I think because the scope of this problem is so big, and so much of it is out of our control, that people end up focusing too much on one little thing and never enough on the big picture. We sign petitions for wanting cleaner water, but do we change our driving habits? We turn off lights, but do we unplug unnecessary appliances?
For instance, I saw an article a while ago talking about the "scandal" that was caused when Cameron Diaz said that she doesn't always flush the toilet in order to save water. She's environmentally conscious, which is fantastic. But...I can't help but wonder, what's the environmental toll of the large house she probably lives in? Of all her new clothes, the traveling I'm sure she does, etc? Is it at all hypocritical of someone to claim that they're "environmentally conscious" if they live in a mansion? I mean no disrespect to Ms. Diaz, I'm sure she's really working toward environmental causes. She just happened to be the example I thought of.
There was also an article (which I didn't actually look at) on the cover of the PETA magazine which periodically gets "donated" to the library touting Lea Michele's efforts to end horse-drawn carriage rides in Central Park. All I could think was, REALLY?! That's what she's going to focus on? Not puppy mills, factory farming (I think those pictures speak for themselves), or any of the other hundreds of animal causes. She chose carriage rides. As I said, I didn't read the article so I don't really know about it. Perhaps the horses aren't kept well? But it's like avoiding the part of an iceberg you can see and then saying, "Whew! That was close!" You're still about to hit the ice under the water, but you're too focused on the superficial view to understand that.
I feel uncomfortable trying to label what I'm doing as "sustainable" because I know it's not. There's a long, long way to go before my own lifestyle is sustainable. Is it even environmentally friendly? I'm sure there's so much that I don't (and that we don't, as a species) understand about the environment that I'm probably as blind as anyone else to how awful my actions are.
Of course, it would probably be best to ignore these gloomy thoughts and listen to Don Cheadle when he says, "every green thing you do has an exponential impact when combined with the actions of others." And then I can help him plant a forest.
On the plus side, I have noticed a severe reduction in the amount of garbage we have every week. So one part of this, at least, is helping.
Also, it was either great naivete or great hubris that lead me to put a compost bin in the backyard and expect that the dog wouldn't get into it. I've now moved it to the side of the house, outside of the fence, and the cat has become my favorite child for the time being.