The Wild File: Food Production
Your urgent inquiries about the world. Answered.
Q. What are we going to eat when the earth can’t produce enough food?
A. You mean, like, when are we going to start cracking open tins of Soylent Green? That 1973 sci-fi flick was prescient in several ways, foretelling everything from global warming to globe-altering famines. There are already famines, of course, and we’ll probably be exploring outlandish nutrition sources this century as the world adds another 2.5 billion people by 2050. ” There just aren’t enough resources to support this kind of demand,” says Arnold van Huis, a professor of entomology at Holland’s Wageningen University and a consultant for the UN Food and Agriculture Organization. The average American eats more than 200 pounds of red meat and poultry per year, and each pound of beef requires six pounds of feed to grow. Scientists like van Huis think we can do better. One answer, he argues, is insect farming. Aside from being easy to raise and nutrient rich, insects require a third as much feed as mammalian protein sources. Better yet, they create a fraction of the CO2 and methane emissions. Still, though grasshoppers and larvae are a delicacy in countries like China and Thailand, making them palatable to an American appetite is a tall order. To solve that problem, van Huis has a plan to turn insect protein into something that looks and tastes similar to a hamburger patty.
The Wild File: Altitude Acclimatization
Your urgent inquiries about the world. Answered
Q. How are Tibetans able to acclimatize so easily?
A. It’s in their genes, of course, but the precise mechanics are still a mystery. This summer, researchers identified 30 genes with DNA mutations that are more prevalent in Tibetans (and presumably Nepali Sherpas) than in ethnic Han Chinese. Tibetans split off from the Han less than 10,000 years ago, a fact that allows scientists to determine which specific genes gave them a high-altitude advantage. Variants of one in particular, the so-called “super athlete” gene EPAS1, have already been linked to improved performance. “Tibetans have a mutation in that gene that is very, very rare,” says University of California at Berkeley geneticist Rasmus Nielsen, who worked on the analysis of the Tibetan data. “Presumably, that is one of the particular variants that helps them perform well in a high-altitude environment.” But how it all works isn’t completely understood. When you or I head to the Himalayas, our bodies compensate for the thinner oxygen levels by producing more hemoglobin, increasing the blood’s ability to transport oxygen. But more hemoglobin also thickens your blood, making it harder for the heart to pump and sometimes leading to acute mountain sickness. Tibetans produce less hemoglobin in their blood yet function well at altitude. Still, not having the gene mutation doesn’t mean you should forget about climbing in the Himalayas. Good training can get you to the top, too.
The Wild File: Carbon Fiber
Carbon is the sixth-most-common element, but while pure carbon in nature can take the form of both diamonds and graphite, you’ll never find carbon fiber in the ground. The high-tensile gossamer strands—which are reinforced with epoxy to make pricey carbon-fiber bikes, fly rods, and tennis rackets—are formed under extreme temperatures in an artificial, inert-gas atmosphere. “The capital investment to make those strands is huge,” says Luc Callahan, engineering manager for road bikes at Specialized. “Like a billion dollars huge.” Indeed, there are only a handful of companies capable of making carbon fiber—all of them focused primarily on aerospace. Once you get beyond startup costs, the raw material isn’t cheap, either. Unlike diamonds produced for industrial use, carbon fiber starts not with graphite but with a tough-to-brew chemical polymer called Polyacrylonitrile. “Compared with steel and aluminum, the inputs are much more expensive,” says Callahan. And, finally, there’s the market. Since carbon fiber’s development, in the late 1950s, demand for it has been set by the aerospace industry. Sports manufacturers get the scraps and don’t even have access to the best military stuff. “We could get 50 percent stronger in some grades,” says Callahan.
By the Numbers
75 Percentage of the carbon-fiber supply used by the transportation, infrastructure, and electronics industries
7 Percentage of the supply now used to fabricate wind turbines
65:35 Ratio of carbon fabric to epoxy resin needed to produce a stable composite in a typical bicycle
42 Man-hours a frame takes to make
$250,000 Cost of the molds and tools for the production run of a single carbon-fiber bike model