• Choose a category
• All
• Classic-Fiction

By Root 1083 0

some of the lowest population densities on Earth, especially in Canada and Russia with only three and eight people per square kilometer, respectively (see preceding table). If all Canadians could be airlifted from their cities and sprinkled uniformly across the country, every man, woman, and child would get their own eighty-two-acre spread. The same exercise in China would yield less than two acres per person; in India less than one.393 But no landscape on Earth is settled uniformly like that. We concentrate in specific places for specific reasons—for arable soil, at strategic trading crossroads, along rivers, and so on. Physical limitations have always influenced human settlement patterns in the past, and they will continue to do so in the future. Obviously, one of the biggest limitations on human settlement in these northern areas has always been the cold.

The Uneven Cold

As a general rule the higher the latitude the more severe the cold (and seasonality, of course)—and the fewer the people. However, being near an ocean does change things. Thanks to the geography of continents and the sluggish, heat-carrying thermal properties of water, air temperatures do not simply vary from south to north, or from low elevation to high, but also with distance from a westerly ocean.394

Take, for example, the line of 45° N latitude defined earlier. On the Pacific coast of Oregon, the average January daytime temperature along this line is 52°F. Moving east through the Montana-Wyoming border, South Dakota, and Minneapolis it tumbles to 22°F. Temperatures persist in the low twenties through Green Bay, Wisconsin (home of the Packers), Ottawa (20°F), and Montreal (22°F) but leap abruptly for ship captains on the Atlantic Ocean, thanks to the Gulf Stream current and its north-flowing extensions that carry warm water north all the way from the tropics. Their heat warms 45° N’s land-fall on a beach in southern France (49°F) and lingers for a while over western Europe. But by Milan (40°F) the warm touch is fading again, and by Stavropol, Russia (25°F), it is gone. Tracing the January averages along this single line of latitude, we found temperature swings of over thirty degrees!

This is the so-called continental effect, in which the interiors of continents experience colder winters and hotter summers with distance from a major ocean, especially on their eastern halves.395 The continental effect helps create the numbing cold of the “Siberian Curse” described in Chapter 5, and the southerly dip of permafrost in eastern Canada and eastern Russia. It is what forces people living in Ottawa to bundle into parkas in winter, while due east in Milan they get by with light jackets and fashionable scarves. It is an important reason why the northern penetration of human settlements has been greater in western Canada than eastern Canada, and in western Russia than eastern Russia. Together with heat from the Gulf Stream and North Atlantic Current, it explains why most of the Eurasian population north of 45° N is piled onto the western end of the continent, and thus the historical agrarian settlement pattern of Europe.

The Coastal and Lowland Imperative

Another important consideration for human settlement patterns, especially in cold places, is terrain.396 Even prehistoric nomadic hunters, who worried little about permafrost or crop yields, preferred low-lying valleys and coasts.

The reason again is temperature. High elevations are colder than low elevations, and usually more rugged too. As a general rule of thumb, air temperatures fall roughly 6.5°C for each kilometer of increased elevation (18.8°F per mile). Thus, high-elevation ground is colder. It allows permafrost to exist farther south than it otherwise would in the mountains of Norway, the mountain cordillera of western Canada, and on the Tibetan Plateau. In Russia east of the Yenisei River, high elevation compounds the continental effect, making these lands among the coldest on Earth. They are deeply frozen in permafrost, useless for agriculture, and frighteningly cold in winter. In North