It's a tough place for moderation right now, especially in the religion vs. science debate (and though I really respect Dawg and realize he's not a part of The Problem, one of the main Problems with monotheistic religion is that by definition it believes that A) There is one answer and B) It belongs exclusively to that religion), but as long as people can back off and consider things, progress towards something can be made.
I don't like Earth Day. One day isn't going to change anything on this scale, at all, ever. The self-righteousness that pervades conversation from both sides of the issue is nauseating. From my examination of the evidence that's been presented, I believe that while humanity isn't the greatest source of atmospheric CO2 at the moment, slowing that growth would probably be a good thing before we get to that point. Truly catastrophic "reset button" events can happen with massive climate change, and while I don't necessarily believe the "Every city under water" predictions will come to pass, I can't feel that it's good to tempt fate if it's avoidable.
Like Asher, though, I believe that we're slowly coming around to a good place on a lot of this stuff. San Diego, for example, is running low on landfill space. The city's enacted some laws with the goal of recycling more of our trash and is making it easier to do so. Landfills are expensive and building a new one would cost everyone a lot of money, so recycling has a tangible benefit here. If that's good for the planet (sometimes debatable, especially with plastics) that's cool, too. If more places with landfill problems got together and started pressuring manufacturers to use less goddamn packaging (I'm sorry, my RAM doesn't need to be outweighed by the package it comes in just so it's harder to steal off the shelf) that'd be even better.
I use some compact fluorescent bulbs (and I want some LED bulbs because they come from the FUTURE) and don't run the air conditioning during the day because that helps keep me below the "penalty" threshold on my power bill. That saves me money. When I'm in the position to buy (or hopefully build) a house, I'm planning on incorporating heavy insulation, tinting windows (for lower insolation), high efficiency appliances, passive cooling, and even a set of solar panels if I can swing it. It's good for the planet and for a healthier power infrastructure, too, but mostly it saves me money. I like money.
I refill my water bottles from a pitcher filter. I don't need to pay for my water to be shipped from another damn continent, nor do I need to haul a batch of bottles to the recycling dumpster every week. My bottles I paid 20 cents apiece for (in bulk, on sale) a year ago are still serving me fine. Again, money.
I'm not able to give up my car due to, well, the fact that most American cities have been built for cars, not people, and so you now need them in order to work and live. I chose my apartment based on proximity to where I work and where I get my food, which means I only drive about 4500 miles a year. I've also found myself being conscious of the way I drive because of gas prices. If I try not to accelerate/brake so much when driving, my mileage goes up. If I'm stricter about my preventative maintenance, my mileage goes up. This saves me money. I like money. My car's 3 months from its ninth birthday, and when it finally gives up the ghost I'm going to pay much more attention to gas mileage on the next one.
CO2 capturing mechanisms exist and are being refined for use on the industrial scale -- they take the CO2 from large operations and use it as fuel for algae farms, which means a pollutant turns into a secondary profit opportunity. While this obviously won't work for all industries (the market for algae isn't that huge, probably), it's a step that can make some businesses money while reducing pollution. That's pretty cool, and it might get other smart people thinking about other smart ways to reduce pollution and make money at the same time. Stuff like that gives me hope.
Things are changing, and while policy changes could make things change faster, by and large attaching a monetary cost to hurting the planet will probably cause a lot less hurting of the planet. Now if only cities could start building up instead of out, and mass transit could become convenient because of that...