Adam Steiner's remark, 'Anyone who would continue to risk inaction on the basis of the evidence presented here will one day in the history books be considered irresponsible' misses the mark:
There will not be future history books if we do not act on global warming now.The current and ever more increasing demands of climate change include terrible human displacement, changes or losses in food supplies.  This is in addition to what we've already managed on our own: almost worldwide depletion of fisheries, decimation of forests and natural areas.

We can turn this around by changing our carbondioxide emissions and converting to sustainable living patterns. A few good references:
Collapse, How Societies Choose to Fail or Succeed, by Jared Diamond
The Future Eaters, by Tim Flannery
The Little Ice Age: How Climate Made History, 1300-1850, by Brian M. Fagan

I guess that only a few people get that if there is no radical change, there is no civilization.  No one to write the history books, no one to read the history books.  Forget the "man behind the "button," when mother nature is unhappy, she is really unhappy.  Without immediate change, civilization will never survive the change in weather.  Lets all go play on the beach.