Global warming, empty bellies
News stories about the recent United Nations climate meetings in Doha, Qatar, generally leaned on the old-standby climate-change impacts: melting glaciers, droughts, heat waves, sea-level rise, and, of course, superstorms.
But of late, a second-order problem has been getting more attention: the worrisome effects of climate change on food supplies.
A recent World Bank report on the dangers of a 4-degree-Celsius (7.2 degree Fahrenheit) temperature rise by the century’s end put food front and center:
The 4°C scenarios are devastating: the inundation of coastal cities; increasing risks for food production potentially leading to higher malnutrition rates; many dry regions becoming dryer, wet regions wetter; unprecedented heat waves in many regions, especially in the tropics; substantially exacerbated water scarcity in many regions; increased frequency of high-intensity tropical cyclones; and irreversible loss of biodiversity, including coral reef systems.
That 4-degree temperature rise could well happen before the century’s end, according to a recent study by scientists John Fasullo and Kevin Trenberth of the National Center for Atmospheric Research in Boulder. They looked at how much warming various climate models – those supercomputer-riding crystal balls – predicted with a doubling of greenhouse gas equivalents over the preindustrial baseline (we’re well on our way). It turns out that models that estimated lower temperatures with such doubling had assumed too little subtropical humidity (humidity being a plug-in proxy for clouds, which are too complex to model globally). The ones with the higher, more accurate assumptions with respect to humidity predicted more warming, Fasullo and Trenberth found.
What’s the connection with food?
Lester Brown and colleagues at the Earth Policy Institute set that table nicely. Brown’s new book,Full Planet, Empty Plates: The New Geopolitics of Food Security paints a disturbing picture of a world on the cusp of food crisis.
Brown, who in 1974 founded the Worldwatch Institute before peeling off in 2001 to create his current think tank, has long since gone global with his Plan B books. But having come up through the U.S. Department of Agriculture, he has a sweet tooth for food issues.
Full Planet, Empty Plates is a thin book with heaps of evidence that global food system, already stretched thin, could well snap with the combined stresses of population growth, soil degradation, freshwater scarcity, and higher temperatures. Climate change will directly impact the latter two, he describes. A few stats:
- Each day brings 219,000 new mouths to our collective dinner tables, or a Colorado’s worth every 24 days
- World food prices have doubled in the past decade.
- Yields (bushels per acre) have plateaued globally, the hybridization, fertilizing and irrigation behind the green revolution having essentially pushed staples such as corn, rice, soybeans and wheat to their photosynthetic limits.
- For every degree Celsius of increased average temperature above growing-season norm, there’s a 10 percent drop in crop yield.
- A one-meter rise in sea level (well within the bounds of scientific estimates) would wipe out half the rice production of Vietnam and Bangladesh (“It is not intuitively obvious that ice melting on a large island in the far North Atlantic could shrink the rice harvest in Asia, but it is true,” Brown quips, in a rare toe-dip into something approaching humor).
- Half the world’s population depends on grain fed from declining fossil (unrechargeable) aquifers.
One comes away realizing that food is water (it takes 1,000 tons of water to produce a ton of grain; 70 percent of our freshwater use goes to irrigation) and vice-versa. And also that dwelling on whether to buy the iPad with Retina display or the iPad Mini may represent a misapplication of our collective cognitive energies. Let’s take it a step further – the notion that we’re somehow becoming a digital society is a total load of manure (which has, despite the organic farm movement, largely given way to synthetic fertilizers). Or maybe just: there’s no app for that. Meat and potatoes are a lot more important than bits and bytes – though meat, given the immense amounts of water and grain it takes to grow it, is part of the problem, too.
Of course, the poor will suffer the most as scarcity spikes prices. According to a 2010 Nomura report, we Americans spend 13.7 percent of our incomes on food, on average, so a doubling of food costs doesn’t hurt as badly as it does in, say, Mexico (34 percent of income), China (39.8 percent) Egypt (48 percent), India (49.5 percent) or Nigeria (73 percent).
If you don’t want to take Brown’s and the World Bank’s word for it, fabled investor and megatrend-spotter Jeremy Grantham wrote in a recent, passionate editorial in the preeminent British journal Nature: “Especially dangerous to social stability and human well-being are food prices and food costs. Growth in the productivity of grains has fallen to 1.2% a year, which is exactly equal to the global population growth rate. There is now no safety margin.”
What to do?
Brown has a few suggestions. Eat less meat. Boost water productivity. Promote family planning and the education of young women. Beat back poverty in the world’s poorest places. Zealously promote low-carbon energy and roll out renewable energy with national-security fervor. Back out ethanol mandates because anything converting grain to fuel (corn-based ethanol being the worst culprit) is exacerbating global hunger.
“Food is the weak link in our modern civilization—just as it was for the Sumerians, Mayans, and many other civilizations that have come and gone,” Brown writes. “They could not separate their fate from that of their food supply. Nor can we.”
Science writer Todd Neff was a speaker at TEDxMileHigh 2012: Risk and Reward and is the author many articles and books, including his newest acclaimed book: From Jars to the Stars
