a team of anl lalysts in britai pored over all the numbers and we have 2,795 gigatons.five times what they think they can burn. but they're going to burn it. >> we will never give up. >> reporter: he organizes and agitates and lobbies for a tax on carbon. he gets arrested for protesting that big new pipeline from canada. and tries to convince colleges to dump their oil company stock. >> so to somebody who says it's a very common political phrase, we need an all of the above strategy, we need clean energy, solar panels, but we also need the keystone xl pipeline because our economy depends on it. and people in emerging markets need to eat. to that you need to say? >> we've got to change because our economy depends on changing. if we let global warming get out of hand, the effects on our economy are equivalent to world war 1, world war ii, and the great depression combined. we look back an the first earth day in 1970. 20 million americans were in the streets, 1 in 10 of the current population then. that's the kind of movement we're going to need if we're going to stand up