Here's an interesting email I got last week that pertains to this subject:
Read the USGS link. There's 3 to 4.3 billion barrels of "technically recoverable" oil. The rest of the "2 trillion" in that email is not accessible to current technology. Oh, by the way, 4.3 billion barrels will last the US about 7 months if you extract it fast enough to meet daily demand.
But "technically recoverable" doesn't even mean "proven reserves" and it also doesn't say anything about the extraction rate. You can have a hundred trillion barrels of oil but if you can only extract it at 1 million barrels per day, it won't be enough to supply a country that uses 20 million barrels a day. Technically recoverable means you can extract it out, but it doesn't tell you how hard it is to extract.
Bakken, oil shales, ANWR and tar sands (which doesn't even belong to you, it belongs to Canada) cannot meet all the demand. They might have a lot of oil, but the production rate isn't going to be fast.
Coal to liquid might get you out of an immediate oil crunch, but there are limits on coal reserves as well. Revised estimates are 100 years at the CURRENT consumption rate. If you use coal to displace oil, that goes down. And if you want to grow your economy as well, that goes down, too.
And for those who understand the science, we also know that burning fossil fuels is a bad thing.
Really, you'd have to be deluded to think that we can continue relying on oil and coal. The switch to alternatives like nuclear and electrified transport should have happened starting in the 70s. Any delay now is just dumb.
By the way, let's look at that email:
However, a recent technological breakthrough has opened up the Bakken's massive reserves.... and we now have access of up to 500 billion barrels. And because this is light, sweet oil, those billions of barrels will cost Americans just $16 PER BARREL!
That's enough crude to fully fuel the American economy for 2041 years straight. And if THAT didn't throw you on the floor, then this next one should - because it's from 2006!
Enough crude to last 2041 years? Never mind that they're throwing around a grossly exaggerated number for recoverable oil reserves (you can't get all of it), a grossly exaggerated number for production rate (you can't extract it fast enough to meet daily demand), the math isn't even right!
Let's see:
US demand of oil is about 20 million barrels / day [1].
At the current consumption rate, 500 billion barrels would last: (500e9 barrels / 20e6 barrels per day) / 365 days per year = 68 years. Not anywhere close.
OK, maybe the author's just a bad writer and means the 2 trillion number quoted later on. At the current consumption rate, 2 trillion barrels would last: (2e12 barrels / 20e6 barrels per day) / 365 days per year = 274 years. Not even close again.
Is he using the other definition for trillion / billion? No, because then the numbers are too big.
[1]
https://www.cia.gov/library/publications/the-world-factbook/rankorder/2174rank.html