I've read we use 3,570,000,000 gallons of oil per day on the planet. So at 80%, 2 856 000 000 gallons go's up in smoke as fuel as you stated.
Now lets address what you said he failed to cover in the interview.
How do we develop a fuel source to replace the over 2.5 billion gallons of petro products that we use to sustain life as we know it on Planet Earth? To accomplish this momentous task I would think we would actually need to ramp up oil production, no?
The development of this new source of energy and the changes to the infrastructure are going to require massive amounts of energy to complete. Not to mention the time such a huge undertaking would require, people are still going to need to burn petro-fuel while the project is underway.
Another hurdle would be financing such a project, we rely on the oil patch not only for day to day living, but its our number 1 export. We shut that down, and our other top 5 exports will also go down with it.
Too me it feels like we have 20 minutes of air left. There is another tank of air, but its 25 minutes away. Everyone is screaming to stop using the air.
If the task was easy, we wouldn't be having this conversation. The rest of the world is already ramping up oil production, and it is actually bad for business. The oil patch isn't hurting because of a bunch stinkin' hippies on a street corner. Its hurting for other reasons (oversupply, falling demand due to economic conditions, pricing cartels etc).
Ultimately, at some point we will be driven to make changes. This is inevitable. This issue is not going away. The stone age didn't end because the world ran out of stones. It ended because we found better, smarter ways to do things. We went from nitro and gunpowder to atom bombs in about 3 years (Manhattan Project 1942-45). Human ingenuity, with the right motivation and resources is amazing.