When the heat came to Russia this summer, torching forests and fields, Lewis Ziska was home in Baltimore tending his weeds. In a matter of weeks, Russia lost a third of its wheat crop and prices rose nearly 50 percent worldwide, prompting bread riots in Mozambique as fear of a grain shortage rippled south and west to Egypt and Eastern Europe. But in the Baltimore sun 90 degrees and suffocating with the humidity the weeds were just fine, which is a good thing, since Ziska believes that one day his weeds could replace wheat altogether.
A plant physiologist with the U. S. Department of Agriculture, Ziska, fifty-three, has spent much of his career thinking about the two hundred thousand people added to the world population every day and how we're going to feed them as the climate heats up. To find out, in the early 2000s he went to where the future climate already existed: inner-city Baltimore. He cleared an abandoned lot, planted it with weeds, and watched in fascination. Fueled by the city's warm temperature and high levels of CO2 both of which match almost exactly the conditions predicted globally for 2050 the weeds in the city lot outgrew their country cousins by 50 percent or more. The lesson was simple: Weeds could survive the worst climate projections, even thrive. Now all Ziska had to do was figure out a way to make them nutritious.
Back in his lab, Ziska and his team are hybridizing cultivated crops which for decades have been engineered to grow spectacularly well under very precise conditions, such as with abundant water and fertilizer with their more weedlike cousins. Currently, they're crossing cultivated rice with wild red rice, a close cousin that is drought-tolerant, grows over a wider temperature range, and, crucially, flowers at night, when cooler temperatures encourage better pollination rates. The new rice should be farm ready in five to ten years. Meanwhile, other researchers are experimenting with weed varieties of oats, wheat, and field vegetables.
Ziska concedes his rice weeds will not be as productive as pure cultivated rice. But they will be a lot more useful. "Modern agriculture is sort of geared up to make Porsches the crops do really well, but only if the track is really fast," he says. "We're looking to come up with a '64 Volkswagen that will go pretty well under all conditions." Even 99 degree heat in the Russian pale.