Everywhere we look we see that the continents were increased by the plastering of fresh silicates from island arc complexes. This is the fundamental deep geology of Ontario and Oklahoma, but they ignore it in the States, and for Bruce Deep Holes.
Like Einstein, I believe in a Friendly God, for things that I don't want to think about. For example, we'd all be dead if water didn't expand when freezing. What if??? Ouch, my brain hurts! But I do know that in human biology, if you find a mechanism that increases serotonin in the brain, you better start hunting for something that destroys it. This is The Balance of a Friendly God.
So, continents keep increasing, but we know that for the last billion year or so, the ratio of continents to oceans has been exactly the same. Look for something that eats continents. If the amount of carbon dioxide increases temperature exponentially and unending,-- look for a compensating mechanism. We have been hit with carbon dioxide before in geologic time. If you want to think harder and don't invoke a God, then call it dumb luck. And we wouldn't be here to yap about it.
I think the compensating mechanism for continents is heat flow. As a thought experiment, double the size of continents. What happens? All Hell breaks loose because that light and fluffy silicate is a great insulator. So, put all these continents together as a Super Continent, and watch out for the fireworks! The Deccan Traps would be nothing. So, it is a simple matter that if we increase frothy silicates, the mantle gets hotter, and pours out basalt. I think during a continental get-together, the edges get eaten off. Even without that, if a continent gets too big for its britches, its deep keel gets eaten, even to the point of creating a Michigan Basin, a great example of mantle-munchies if I ever saw one. :)
I think this will be the great next thing in tectonics -- Continental Breakfast.