> How do you know it isnt natural? 

Because there is 49,933 years worth of data which shows otherwise.

Listen, I'm about the most rational person out there when it comes to the climate change debate -- 90% of these comments are either from deniers or from snowflakes who are picking and choosing from sources to make their (not so good) point.  But in the face of the indisputable CO2 data on hand, to call me hysterical is completely asinine.