So much that once seemed inexhaustible has already been worn away by our needs, our numbers, and, too often, our shortsighted greed. We've reached the place now where our hunger for more of everything has pushed the world's natural resources to the breaking point.
All but 10 percent of the large fish in the seas have been plundered; fully a quarter of the planet's fertile soils have been degraded by overuse and misuse; and the atmosphere has filled with greenhouse gases even faster than expected just a few short years ago. As human population has quadrupled during the past century, the world economy has increased 14-fold, industrial output 40-fold, and the area of irrigated land five-fold.
The past few decades have seen some of the most astounding increases in industry, trade, and overall wealth in history. The benefits of economic growth and global commerce have been enormous—more than 300 million Chinese have been lifted out of poverty. But the costs have been dramatic, too, in part because economic shock waves travel with such speed through our interconnected systems of finance, production, and exchange.
Our industrial, globalized world has been built out of a vast array of minerals, metals, and ores, and powered by vast reserves of fossil fuels. Once these are gone, we'll have to do without, find replacements, or scramble ever harder after less accessible or lower quality deposits. Take petroleum, as just one example. Initially valued for the remarkable ease with which it could be drawn from the punctured earth, most ready supplies of the fuel have already been tapped. That has pushed prices up, as well as driving production farther offshore and into more remote regions.
So many of these problems are connected, of course—the environment, population, food, access to fresh water, and the raw materials of commerce—and not just in the obvious ways. Certainly, fossil fuels and burning forests have driven climate change, and increased industrialization has spurred global warming as well as local and global pollution.
But increased wealth has also spurred people's appetites, boosting the demand for luxury foods such as seafood and beef, and leading to oceans emptied of fish and rain forests cleared not only for cattle but also for soybeans and oil palms planted to make biodiesel to replace climate-changing fossil fuels. And of course it was petroleum, in the form of diesel-powered fishing vessels, that extended the reach of our nets and lines to every corner of the oceans.
With even modest economic growth, we'll not only have more people but also more people wanting more and better food, more travel and tourism, more basic goods and luxuries and just plain stuff. And that means more mines and oil wells, more livestock raised and fertilizer- and water-hungry grains grown to feed them, and more cars and factories and airplanes to fill the air with heat-trapping gasses. It means mountains of waste of every description.
The decades ahead will present many challenges to humanity. We'll need to find new sources of energy to power our lives without choking our air. We'll need to learn to recycle and reuse on a scale not yet imagined, and to balance the convenience of consumption with the wisdom of conservation. Perhaps most importantly, we'll need to develop ways of doing much, much more with our planet's limited supply of fresh water. We'll need to do all of this with a changing climate and a growing population—and with the one very limited planet we've had all along.