I give the Slashdot posters a collective D- failing grade.
The early posters get a D- for their really weird inability to say three fresh and funny things about the OP.
The middle posters, get a D- because 90% of the posts are tired sighs.
The tired sighs of many previous posts are an important sign that the global warming problem is a slow moving massive event where the principal indicator of it's progress ( CO2 levels) has not gone down even though we have been through a 5 year economic depression. The abating economic depression did not slow down society enough to affect CO2 levels. (There was a little decrease in the rate of increase, but not in the fact of increase.) The sighs reflect the disappointment and fatigue of many people on this list who have tried to reduce their CO2 footprint and see that all the effort produced no result. CO2 increase is an intractable, slow moving, massive problem.
And lets issue another D- to everybody that cites an expert and therefore excuses themselves from engaging with the global warming problem. If you live a typical drive to work life you are contributing 3,000 to 10,000 pounds of CO2 to the atmosphere every year. Could you possibly reduce your CO2 emission to the level of a 1776 pre steam engine individual? In this case, the phrase "massive problem" means exactly that: a large amount of human generated mass. No matter how subtle the argument, 3000 pounds turned into infra-red absorbing Carbon oxygen bonds is about the mass of your car. Rhetoric is not enough.
Welcome to the lonely world of social change. The problem in front of us is still how to emit 1/2 as much CO2 every day for you, your wife and your kids without losing the happy and fun mechanical conveniences we enjoy and maintaining economic and social stability.
(I am not a chemist, but 2 gallons of gasoline x 7 lb per gallon x 365 days => about 5000 lbs, not counting the weight of Oxygen from air making CO2.)