Several reasons. From a current geographical point of view, it shares a tectonic plate with North America, and can reasonably be considered part of the North American continent. Additionally, while large, it is still a lot smaller than the smallest continent. read more
Additionally, while large, it is still a lot smaller than the smallest continent. Greenland’s area is 836,000 square miles, while Australia’s is 2,970,000 square miles (3.5 times smaller). It looks huge on certain map projections due to it’s polar location. read more
Even though Australia is the smallest of the accepted continents, Australia is still more than 3.5 times larger than Greenland. There has to be a line in the sand between small continent and the world's largest island, and traditionally that line exists between Australia and Greenland. read more
Greenland is the world’s largest island, over three-quarters of which is covered by the only permanent ice sheet outside of Antarctica. With a population of about 56,480 (2013), it is the least densely populated country in the world. read more
Everyone agrees that everything smaller than Australia is an island. Australians themselves are divided, and often claim that Australia is both the world's largest island and the world's smallest continent. So, there are good reasons to assert that Australia is a continent and not an island. read more