I'd have to believe it does. Just as each of us does a little driving each day contributes to CO2 and thus to global warming, each of us can also switch to compact fluorescent lightbulb and hopefully decrease the CO2 that is created. I had previously asked myself this here when I started new magazine subscriptions (more trees cut down!) and when I was shredding our old checks (does it really prevent ID theft?).
Now the Washington Post is reporting that antibacterial soap can result in antibacteria-resistant germs. Here is another example of how small actions by each of us can contribute to a potential health problem. But can it? It sounds theoretically plausible but as the article points out there is very little direct evidence of this.
In economics there are also many theoretically plausible models but the evidence isn't always there to support the model. There are many smart economists who can always build a model that can deliver theoretically plausible results to demonstrate causality. However, finding the evidence and data to support the model is the real hard work. One such model is Ricardo's theory of comparative advantage but this is for another time.