Is there any legit reason why Greenland would be considered "not a continent", while Australia is one

Question

Aside from the obvious difference - size... all continents and all islands have a different size.

Is the boundary between these two islands/continents just an arbitrary one?

Answer 1

SIZE IS THE DETERMINING FACTOR.

Answer 2

Good question!

The definition of continent is a bit arbitrary.

Greenland population is 56,000+ and the "island" belongs to Denmark. It is slightly bigger than Mexico.

If it gets warmer, it may become the 6th continent.

Remark. Europe should not be a continent, it should be called the Euro-Asia continent.

Answer 3

At one time, Greenland was considered to be a continent.  However, scientists require an island (such as Australia) to be on a separate tectonic plate to qualify as a continent.  Confer with continental drift, etc.  Therefore, Greenland is considered to be part of the North American continent, but is in fact the largest island not a continent.