No. That’s the short answer. But we can elaborate a bit.

It depends on what we mean by “land.” Are we talking about land on which to live? Land on which to grow things? Or land on which to grow things in an environmentally sustainable fashion? Our answers could vary on these, depending in part on whether we choose to be technological optimists or pessimists.

World population is expected to increase from its current 6 billion to about 9 billion people by 2050, at which point, given present fertility trends, it will level off. That’s a lot of people, but the earth is big, and humanity, despite our billions, doesn’t take up too much physical space. Most of the world is sparsely inhabited—for good reasons! So it’s not like we won’t be able to find a place to stand in the future. We can always build up (like we do now) or build down (which science fiction writers like to talk about). We won’t have to completely pave the earth.

The far more important question is “With all these new people, will we run out of food?” That’s the issue that underlies the writing of Malthus, who responded to a similar question 200 years ago. He said humans periodically breed too fast, and we run out of food as a result. Certainly, parts of the world are seen to run out of food on too-frequent intervals, but most economists who’ve studied famine agree that food shortages are brought on by human political failings, not by agronomic shortcomings. We grow enough food; we just don’t distribute it well enough.

But our record is not so sterling when it comes to choosing and managing land to grow food without screwing up the environment. Erosion, nutrient and pesticide pollution, degraded habitats—we’ve done them all. Doing better is not a technical issue. We know how to grow plenty of food—enough even for the expected larger world population—and we know how to do it without making future generations worse off. Putting it all together is a matter of political will and prudent economic analysis.

For an interesting discussion of this topic, check out wikipedia.com's article on ecological footprint.

– Steve Taff, Associate Professor in the Department of Applied Economics