What if Earth's landmass was divided into 4 large continents like in Game of Thrones?

Imagine that the Americas, Europe, Africa, and Asia are replaced by 4 large continents. By large, we mean that each of these continents would have an area similar to that of Asia or Africa combined. There are many intriguing consequences of such a world. For instance, the climate, geography, and natural resources would likely be quite different from those on our planet.