Doesn't the climate vary naturally?
Yes - the Earth's climate swings naturally from ice age to jungle warmth. But it's usually an incredibly slow process.
It takes massive global changes to cause an ice age. One theory suggests that when continents drift into one another, pushing huge areas of land to higher altitudes, the surrounding ocean and atmospheric patterns change radically.
This time, our climate isn't following the rules of previous slow-moving changes.
| 
|
