Global economy: Meet Mr. Doomsday

Predicting doomsday is hardly a new concept.

Many people have put forth end-of-the-world scenarios — from the ancient Mayans, to Nostradamus, to 18th century economist Thomas Robert Malthus, to contemporary crackpots like Harold Camping (who, incidentally, has reportedly suffered a stroke).

You can now add legendary Wall Street investor Jeremy Grantham to that esteemed list of doomsayers.

With a hat tip to our friends at Business Insider, Grantham is painting a very dark picture for humanity these days.

According to the co-founder of global investment firm GMO, the world has entered a permanent "paradigm shift" whereby the number of people has outstripped planet earth's ability to support all of us.

That's especially true for economic growth materials like oil and industrial metals.

It's also true for that other thing we humans use every day: food.

Here's how Business Insider summed up the argument:

Grantham believes that the trend of the last 100 years, in which the prices of almost all major commodities have steadily declined, is permanently over. And from here on in, humans will be competing more–and paying more–for ever-scarcer resources.

Grantham believes that the planet can only sustainably support about 1.5 billion humans, versus the 7 billion on Earth right now (heading to 10-12 billion). For all of history except the last 200 years, the human population has been controlled via the limits of the food supply. Grantham thinks that, eventually, the same force will come into play again.

Of course, Grantham could be wrong and science might once again race to the rescue of humanity.

Malthus, for instance, famously underplayed the role of productivity in agriculture, which allowed fewer farmers to feed ever more people.

But if you'd prefer to bum out today, here's a handy slideshow that lays out Granthan's depressing thoughts.

Happy Monday.