From xkcd: http://www.xkcd.com/164/

Science is about facts and evidence.  There is a lot of evidence that carbon dioxide is a greenhouse gas.  You can explore with our models how carbon dioxide impacts the global temperature.

Politics is about what to do about those facts.  But politics too often turns into a blame game, in which people take sides without really listening to the evidence.

Do we ban the burning of fossil fuels because it increases carbon dioxide emissions?  Do we look  for ways to capture all carbon dioxide emissions from human activities?  Do we impose a “carbon tax” on all goods?  What would be the economic impacts of these policies?  Is the electronics-centric lifestyle to which we’ve become accustomed even compatible with low carbon dioxide emissions?

In the end, it all comes down to a cost-benefit analysis of the risks and rewards for each course of action.  What risks do we undertake by doing nothing?  What risks do we undertake by completely changing the ways by which people travel around the world?  What benefits do we gain from each action?

But to do a cost-benefit analysis, we have to understand the facts; we have to understand our “known knowns”–what we know we know–and our “known unknowns”–what we know we don’t know.  We have to remember that there are always “unknown unknowns”–those things that we don’t even know that we don’t know.

That’s why it’s up to each of us, as individuals, to learn about the science–about the facts and the real evidence and what’s still not fully understood–and then choose our actions based on our own understandings of the facts and preponderance of the evidence, not on someone else’s views.  We have to think for ourselves and act accordingly.

But we also have to remember that our actions impact those around us.  We’re all on this planet together.