I'm tired of people preaching about global warming to me when they don't even know what an interglacial is... or the fact they've been happening about every 100k years for the past 450,000 years. For the last 400,000 they were a normal cycle, but now this one is because I drive an SUV.
It's not just climate change that's the issue.
There's also peak oil, which is actually an even worse problem. It doesn't get a lot of press now when the oil prices are low, but everyone should be aware that there's only a finite amount of that stuff. More importantly, it's getting harder to increase production rates to keep up with demand - more and more energy is needed to get at it. Different groups have different predictions for when we can no longer increase production to meet demand but it's in the 5 to 30 year range.
Oil shale and tar sands won't be enough to help this. While there's a lot of it, you can't get the oil out of it fast enough to meet demand. Drilling the in Arctic? Likewise.
There have been "big" offshore finds recently in the range of billions of barrels. That only lasts 20 years at most given current oil demand, but again, it's not the total amount that matters but the rate you can produce it. It's pretty useless if you need an extra 5 million barrels per day to keep the lights on but can only extract 1 million.
Coal and natural gas? Those will run out too.
It's just simply much better to switch away from fuels that are going to be exhausted in the short term (20 to 100 years, including coal) as early as possible. If you wait till they run out, switching is impossible (e.g. building a power plant requires oil). Nuclear power supplemented by solar thermal, wind and hydro where feasible is far more sustainable in the long run. Conservation now will stretch out the energy supplies so we have a chance to do a massive build-up of other energy bases (it takes years to build a nuclear power plant).
Nuclear is actually much better than many environmentalists give it credit. It's just a politically charged topic combined with a lot of public ignorance.
So in short, whether it's anthropogenic climate change (which is real as far as the science is concerned), peak oil, or politics (countries are willing to fight wars to get energy), humans should reduce fossil fuel usage. And we should reduce it as fast as possible - because it takes time to build up the alternatives and we can't afford to wait much longer to get started.