The reason Scandinavia is one of Earth's most distinctive peninsulae is the Baltic Sea, which is actually the result of glacial retreat during the Last Ice Age, so it wasn't a geologically ancient body. Indeed, evidence has found that before the Pleistocene, the Baltic Sea was actually the Baltic Plain.
In this alternate scenario, the geological timeline of the Baltic Plain is as follows:
- 250 million years ago, Scandinavia collided with mainland Eurasia, resulting in a mountain range as tall as the Himalayas today. Since then, the rocks had been crumbling.
- 5 million years ago to today, repeated ice ages smothered Scandinavia, yet unlike ours, the Baltic Plain still stood strong.
So if the Baltic never became a sea, if we still have the ancient Baltic Plain, would it have any major differences to European climate, landscape and culture?