My thoughts: It's extremely pathetic that global warming is even considered a "controversial issue" by the general public, even when the long-term habitability of our planet is both a moral and ethical issue, and the evidence is so extremely clear that we are having a deleterious impact on the global environment that sustains us all. Our global civilzation has been pumping obscence amounts CO2 into the atmosphere since the first coal was burned, into an atmosphere thinner than a layer of paint on a ten meter by ten meter wall. The planet cannot naturally balance the levels in the atmosphere to their "safe" range of normal greenhouse effect; the kind that traps just enough solar energy and prevents our planet from freezing. Not a single atmospheric scientist or scientific publication doubts the existence of advanced global warming because of human factors (just as no biologists doubt the validity of evolution). If the public were simply less ignorant of the science and evidence for the issue in question, there would be absolutely no debate on whether global warming was taking place. Why is the public being kept ignorant or being sent mixed messages about global warming? Power, money, and the fear of disquieting facts. Let's not make the ultimate mistake and give the burden to our children of coping with the devastating and long-term ramifications of our behaviors when we neglected to act during a time when catastrophe was preventable.
My take on the ethical aspect: you cannot plan for a sustainable future when you have people in power (like Bush) who believe that the world is doomed for a bible-style apocalypse where a sky-god will come down and save us from ourselves at the darkest hour. Humans are alone, and it is we that are accountable for our own actions, something that many religious persons like to pretend isn't true. It's up to us; we have the ultimate power to prosper as a species or let our global civilization fail.
If we don't act drastically now, it will be too late. A broad understanding and recognition of global warming has to happen first. And it has taken some important steps toward global acceptance. Except, however, in the U.S., where these steps are far to small and far too slow to work toward an ultimate solution.
As Carl Sagan said, "Anything else you're interested in is not going to happen if you can't breathe the air and drink the water. Do not sit this one out. Do something."