"Iran's oil exports will shrink to zero in 20 years"
The thesis is dependent on the claim that the end of Iran's oil is 20 years away, but Iran has 90 billion barrels of reserves, 9% of the world total, and just discovered what is likely another 38 billion barrels. I can't see Iran running out of oil until the world runs out of oil.
There are number of ways to estimate global consumption. I just threw together a wicked simple linear estimation and it gives Iran about 40 years to pump out and deliver its 2005 proven reserves. I have faith the author spent more than five minutes [as I just did] to come up with the 20 year estimate. Nevertheless, I would like to see how the author did it... "Trust but verify" -RR
This figure also does not take into account the humongous vein assessed to be in the Caspian. There are reasons to believe the untapped oil in the Caspian may be some of the biggest sources ever discovered. Rights to these reserves are currently under dispute between the various players.