Excerpt / Summary 1 MORE PRODUCTIVE LAND Share on Twitter Economists point out that we keep improving the productivity of each acre of land by applying fertilizer, mechanization, pesticides and irrigation. Further innovation is bound to shift the ceiling upward. Jesse Ausubel at Rockefeller University calculates that the amount of land required to grow a given quantity of food has fallen by 65% over the past 50 years, world-wide. 65% The amount of land required to grow a given quantity of food has fallen in the past 50 years.
2 OVERESTIMATING WATER DEMAND Estimates made in the 1960s and 1970s of water demand by the year 2000 proved grossly overestimated: The world used half as much water as experts had projected 30 years before. The reason was greater economy in the use of water by new irrigation techniques. Some countries, such as Israel and Cyprus, have cut water use for irrigation through the use of drip irrigation. Combine these improvements with solar-driven desalination of seawater worldwide and it is highly unlikely that fresh water will limit human population. Drip Irrigation
ASSOCIATED PRESS 3 THE SHALE REVOLUTION Until about 10 years ago, it was reasonable to expect that natural gas might run out in a few short decades and oil soon thereafter. If that were to happen, agricultural yields would plummet and the world would be faced with a stark dilemma: Plow up all the remaining rainforest to grow food, or starve. But thanks to the shale revolution, peak oil and gas have been postponed. Hydraulic Fracturing
ASSOCIATED PRESS 4 ALTERNATIVE SOURCES Phosphorus is vital to agricultural fertility. The richest phosphate mines, such as on the island of Nauru in the South Pacific, are all but exhausted. Does that mean the world is running out? No: There are extensive lower grade deposits, and if we get desperate, all the phosphorus atoms put into the ground over past centuries still exist, especially in the mud of estuaries. It’s just a matter of concentrating them again. 5 GREATER AFFLUENCE AND NEW TECHNOLOGY In many respects, greater affluence and new technology have led to less human impact on the planet, not more. Richer people with new technologies tend not to collect firewood and bushmeat from natural forests; instead, they use electricity and farmed chicken—both of which need much less land. In 2006, Mr. Ausubel calculated that no country with a GDP per head greater than $4,600 has a falling stock of forest (in density as well as acreage). |