Does it? Does it matter if the Earth is getting warmer, the oceans are rising, and all of the other side effects of all of this carbon dioxide in the air?
Would people be more likely to not recycle if it was proven that global warming does not exist? Would they care if the oceans weren't going to rise? Would they not feel any regret driving their gas guzzlers, as they might do now if they believe global warming exists?
There is very good evidence for and against the existence of global warming, and I am not sure how I feel about this issue. The fact remains that, I do not care if they oceans rise and the earth gets hotter. If every bad thing global warming is supposed to cause doesn't happen, I will still feel the same.
Taking these "green" actions will still have an impact if global warming doesn't exist. Anybody who lives in or nearby a city knows what smog is like, and it is harmful to health. So, even if the CO2 given off by cars doesn't heat up the earth, the effects of less CO2 in the air would be apparent, and positive, and health would certainly be improved. Also, that can that may or may not be recycled will still have an impact.
If not recycled, that can will have to be dug out of the Earth, harming nature for the search of metals, and then wasting energy and creating pollution when brought to the plant by car, and then by being produced in the plant. On the other hand, if the can was recycled, nature wouldn't have to be destroyed to dig the metal, and less energy/pollution is used by the plant to make a new can from the old one. (I will admit, to avoid angry comments, that some pollution will be produced while the can is transported to the plant, but altogether, less harm is done.)
I think you understand my point now, that what will "prevent global warming" will still have an impact whether it truly exists or not.
Also, I ask you to never think that "this one can won't make a difference, I don't see a recycling bin, so I'll throw it out." Every little piece has an impact, no matter how small.
One person may be small, and one million people are definitely huge, but it takes one million of those individual small people to make that huge one million. Same goes for that can, that newspaper, that plastic bag, and every light that is kept on.
Everything is connected to each other, and it is up to us to break the connecting chain of waste.