Civilization and the thread of distribution

As the northeast braces for the season's first big snowstorm, the thread that holds the entire region together, transportation of food and fuel hangs in the balance.  More than likely, it won't be as bad as the weather channel is painting it, but what if it was worse.  30 or more inches of snow in major metropolitan areas can cripple transportation for days.  People are trapped inside and major food distributors can't get supplies or ship what they have in stock.   Within 48 hours civilization can be hanging by a thread.  In this case we are talking about a snowstorm.  What would happen if a truly global event disrupted the supply of food and fuel for weeks or longer.  What would our vaunted civilization look like then.  It is worth a thought, especially when the threats posed by climate change begin to present themselves.