There are really three separate issues that are lumped together:
1. Is something happening with the climate?
2. Is it natural or human-caused?
3. If there is something going on, is there anything humans can do about it?
For those trying to make up their own minds independently, look into these questions separately and rationally. Try not to decide based on emotions or what "camp" you are in.
We know the deniers' sources are traced to conservative think tanks and the oil companies that fund them. We also know the green side is trying to make bank off hysteria too, with wind farms, solar companies, green toilet paper, and anti-incandescent light bulb peeps. (This last one really annoys me, as regular light bulbs are getting the axe next year and then all you will be able to buy are the mercury light bulbs that you will have to treat like toxic waste when you dispose of one or it breaks!)
1. As for me, whether you want to call it global warming, climate change, or a natural cycle, I think there is something going on. Just visit Glacier NP and use your eyes.
2. The earth is ancient and there are have always been natural cycles of greenhouse earth, ice ages, and more, including warm and cold cycles within ice ages (and we are in an ice age). The majority of climate scientists state that human beings are impacting this cycle to a large degree. A minority either denies it or is unsure.
3. If human beings are impacting it, logically they can decrease that impact.
The bottom line for me anyways: something is going on, but the reality is, human societies are not proactive, they are reactive. That means we won't do anything until it is too late. We are adaptable. Some humans at least will survive whatever is coming. But our current global economic system is based on the status quo (oil, energy use, resource depletion) and IT won't survive. It will get very ugly before we come out the other end. Whatever "we" is left.
PS. Sending prayers for the people of northern Japan. I haven't yet heard anything about how this has impacted the Ainu of Hokkaido.