The more inefficient the supply chain is, the greater your positive impact on global resources will be when you just quit buying their crap.
Peak oil does not mean a literal shut-off of supply. It is not like you will hear a sucking noise as if your soda straw had finally and suddenly pulled the last of your drink out of the glass. The gradual and inevitable process, now in full swing, will be that the amount of oil that it takes to fetch a barrel of oil to your local pump will increase steadily. The efficiency of the supply chain is up against a hard and declining physical limit. The worst danger is the years-long gradualness of the process. That creeping change will let our over-adaptive brains revise the threshold of alarm. We tip-toed past the alarms of 1973 and then sped up again. We don't hear those alarms any more. We don't hear anything but advertisements for cars.