It was forty years ago that a group of scientists poured as much data as they could collect into a supercomputer and crunched the data. Their goal: to project trends into the future and see whether there were limits to growth. At the time — and even today by many — the assumption was that growth could continue forever. This naive concept is directly contradictory to the fact that the Earth is finite. At some point in the future, we will meet up with the fact that our finite planet will simply run out of the resources we need to continue growing.
Well, folks, it's now forty years later and we can compare those projections published in Limits To Growth and see just how close we're coming to them.
First, the amount of non-renewable resources remaining: They have been declining only slightly less than the projection. We are running out of these resources rapidly even so. By 2030, we are projected to be down about 70% from 1970 levels. What can we do? Mine asteroids as best we can and make do as best we can with what we have left.
Second, the amount of food available per capita: This is becoming an extreme problem as global warming interferes with our ability to grow enough food to feed our exploding population. The Green Revolution, it turns out, was simply a stop-gap solution and we increasingly are seeing problems feeding our 7 billion human population. What can we do? Practically, the only solution for us is a lower population. We can never hope to raise food production enough to feed an ever-increasing number of people.
Third, the level of human population itself: It has continued to grow at about the trend projected in 1972. In other words, at an unsustainable pace. Most of the growth is in areas of the world which have lifestyles much less energy-intensive than the developed countries. Newly-developing populations are going to put demands upon our resources which we frankly cannot meet. This trend will continue until 2030 according the Limits Projection, at which time human population will start to undergo a steep decline. There seems to little we can do to change this projection. The result: There will be far fewer humans on Earth at the end of this century than there were at the end of the last century. This is inevitable, and only those people who emigrate off-planet will live in relative comfort and security.
The other projections, as you can see below, are following the paths projected for them. In particular, notice that the Industrial Output Per Capita curve is now reaching its highest point right now and is projected to be rolling over and plunging in coming years. We are certainly living that curve right now, which no one can deny.
The bottom line: Without massive colonization of the solar system, the human race is running up against rock solid limits to growth over the next couple of decades. We should be planning for how we are going to deal with these limits. If we don't, we will become the victims of these limits.