"Iceland, though it lies so far to the north that it is partly within the Arctic Circle, is, like Norway, Scotland, and Ireland, affected by the Gulf Stream, so that considerable portions of it are quite habitable"

In the quote by Harry Johnston, we discover a geographical and climatological observation that highlights the distinct environment qualities of Iceland, as well as its habitable nature despite its northern latitude. Johnston begins by keeping in mind Iceland's geographical positioning, highlighting its proximity to the Arctic Circle. This detail is crucial, as areas within such high latitudes are normally connected with severe, cold environments, which might render them inhospitable or difficult for human habitation.

Nevertheless, the quote exposes an interesting contrast by introducing the Gulf Stream, an effective, warm Atlantic ocean present that comes from the Gulf of Mexico and flows across the Atlantic Ocean towards Europe. Johnston draws a parallel between Iceland and countries like Norway, Scotland, and Ireland, which are likewise influenced by the Gulf Stream. This ocean current is known for its climate-moderating effects, significantly affecting the weather patterns and temperatures of the areas it affects.

The warming result of the Gulf Stream on Iceland suggests that, in spite of its northern area, the nation benefits from relatively milder winter seasons and more temperate environments than may be expected for an area so near the Arctic Circle. As a result, "substantial parts" of Iceland are referred to as "quite habitable." This expression suggests that while not the entire country is easily inhabitable due to its rugged surface and volatile weather condition patterns, there are considerable locations where people can and do live conveniently.

Johnston's observation highlights a remarkable aspect of geographical climate characteristics, where ocean currents can develop microclimates that defy expectations based exclusively on latitude. This phenomenon enables Iceland, along with similar areas, to support human populations and develop unique eco-friendly and cultural landscapes. The quote eventually indicates the intricate interaction between geography and climate, illustrating how natural forces form the habitability of our world.