It is, however, a simple way for individuals to avoid growing their carbon footprint. Not doing something is easier than changing an entrenched lifestyle. It's the same as saying "don't buy a large home", "don't buy a large vehicle (or preferably any vehicle at all)", "don't travel" - you're not missing out on anything, you're simply avoiding a destructive behavior. If you have a dog or cat already there isn't much you can do about it at this point.