Take a look at the double pendulum simulator at: http://www.myphysicslab.com/dbl_pendulum.html .  Global warning represents a shift of the pendulum a bit to the right, so grab the middle ball and move it to the right.  You’ll notice that the bottom ball swings rather wildly.  The more you disturb the middle ball, the more wildly the second ball swings.  This chaotic behavior is seen with a pendulum with only two balls.

Now realize that the Earth’s weather is like a pendulum with billions of balls.  If you add more energy (through global warming) you’ll end up with gigantic chaotic behavior with balls swinging more to the left (colder) and to the right (hotter) than usual as well as the average of the balls moving to the right (the actual global warming).  So instead of thinking, “hey, it’s unusually cold, that means global warming is false,” after looking at the double pendulum I suggest you consider: “hey, it’s unusually cold, they may be right…”