This is a map of Earth as depicted by the DeviantArtist ToonHolt:
As you can see, many new landmasses have been added, from lost worlds like Sundaland, Zealandia and Kerguelen, to fictional worlds like Mu, Atlantis and Lemuria. Some of these extra landmasses used to exist, others never did.
But in the event that this is a map of Earth in the 21st century CE, it would require a massive point of departure, one in which humanity would be butterflied out of existence. Before we get to the geography and the climate, the first question would be:
What point of departure, chronologically and geologically, would be required for this kind of Earth to exist?