Only 10% of the world's population lives in the southern hemisphere

It's a weird population discrepancy

Photo by Andrew Stutesman on Unsplash

Have you ever looked at a world map and noticed how much of the landmass seems to cluster towards the north? It’s not because the map above is a Mercator projected map, which is infamous for distorting far northern and far southern landmasses. Our planet is home to over 8 billion people, but roughly 90% of humanity resides in the north of the equator. This leaves vast stretches of land in places like southern South America, southern Africa, and Australia with remarkably low population densities. Which is bizarre because, at least as far as Africa and Australia go, these places are home to some of the oldest continuous human cultures in the world. So why didn’t they grow into larger populations?

Speaking of Australia, I originally started pondering on this question because I created a video about Australia’s own bizarre population divide, this one inverted though. Check it out right here:

Land vs. ocean

One of the most immediate reasons for the population disparity between the north and south is the sheer difference in landmass. At its most basic the northern hemisphere simply has more land. If you look at the globe, you'll see large continents like North America, Asia, and Europe (though much smaller than the other two) located almost entirely north of the equator. In fact, only Indonesia exists both north and south of the equator, which could honestly be considered more Oceania, though that’s getting beyond the point of this article.

By contrast, the southern hemisphere is dominated by ocean which covers about 80% of its surface. And while the southern hemisphere does include South America, Africa, Australia, and Antarctica, the total land area is significantly smaller. And as far as South America and Africa go, huge parts of both of those continents are actually in the northern hemisphere. At its most basic: more land means more potential for inhabitable regions, more resources, and ultimately, more space for people to live. The fact that one whole continent of the southern hemisphere drifted so far south (Antarctica) that it became completely uninhabitable certainly didn’t help.

Climate and comfort

Beyond just the amount of land, the type of land also plays a critical role in population diffusion. As it turns out, much of the northern hemisphere benefits from a more temperate climate that has historically been ideal for large-scale agriculture and human settlement. The vast fertile plains of North America, Europe, and especially Asia provided conditions that were more conducive to supporting larger populations historically. Take the fertile crescent area of the region we know today as the Middle East. This area was so fertile that it actually bore the beginnings of continuous, settled agriculture. A place where humans could stay and live without needing to pack up and move as the weather or land changed. It’s also one of the first places where irrigation was used.

Of course, the southern hemisphere certainly has its own fertile regions but a significant portion of its land is either very arid (like much of Australia and parts of southern Africa) or extremely cold (like Antarctica, which has no permanent human population). Even within the continents of the Southern Hemisphere, a substantial portion of the population tends to cluster closer to the equator or along coastal areas where the climate is more hospitable. For instance, while Brazil is a large country in the Southern Hemisphere, its population is heavily concentrated along its eastern coast and in its warmer northern regions.

Migration and development

Historic patterns of human migration and development heavily favored the northern hemisphere. Early civilizations, from Mesopotamia to the Indus Valley civilization and ancient China, largely emerged and flourished north of the equator. These foundational societies developed agricultural techniques, established trade routes, and built empires, laying the groundwork for sustained population growth.

The "Age of Exploration," while it eventually led to European powers colonizing much of the southern hemisphere, began from northern hemisphere bases. The subsequent industrial revolutions, largely centered in Europe and North America, further accelerated population growth and urbanization in these regions. The established infrastructure, trade networks, and economic opportunities continued to draw people to the Northern Hemisphere, creating a self-reinforcing cycle of growth.

So, while the thought of vast, sparsely populated landscapes in southern Chile, the Australian Outback, or the Karoo region of South Africa might be beautiful areas of the planet (and they are!), they also serve as a stark reminder of our planet’s uneven population distribution.

But here’s the kicker…

I’ve just gone on at length about the reasons why the northern hemisphere has the vast majority of the world’s population. But it’s not even really a north vs. south thing: it’s a northeast vs. the rest of the world thing. If we just take the northeast quadrant of the world, which would include most of Europe, much of northern Africa, and nearly all of Asia, you end up, again, with most of the world’s population. Most of which is actually south, southeast, and east Asia. India and China alone are home to nearly 3 billion people, which is just a mind blowing statistic even if its well-known.

So why does the northern hemisphere have most of the population? Well because that’s where India and China are located. The rest of the world has relatively similar populations.