This is nonsense. When the guys/gals LOOKING for oil realize that the easy stuff is running out the price will start to rise. How "gradually" it rises will depend on the speculators. But over time the price WILL rise and it will meet on the curve with renewable sources and THAT is the point at which we will see the renewables take off.I heard that it will be a sudden drop off
But as Toshi points out - we'll probably be good for our lifetimes. So don't expect anything "drastic" to happen any time soon.