농업의 버팀대: 더 나은 식량과 기후

The National Climate Assessment, released this week, predicted increasingly negative impact of weather extremes on crops. But with industrialized farming as a key player in greenhouse gas emissions and climate change, the vicious cycle needs breaking.

Jacky Chen/Reuters

This past year treated us to a climate change preview in spades: crazy heat waves, prolonged drought, and epic storms like Sandy. To help us stabilize the climate, before we reach the point of no return, we must tap the immense potential of our food system.

Since becoming an agrarian society, we've known that growing food successfully depends on climate stability. Not enough water, crops wither and die. Too much, they rot. Beyond this, we know that crops have specific climatic requirements. Wheat, for instance, grows best in a dry, mild climate. Stone fruits like cherries need a minimum number of "chill hours" in order to blossom and later fruit. Intense heat disrupts pollination and can even shut down photosynthesis. These are basic parameters. If we continue to disregard them, food will become more scarce over time and we will go hungry. Indeed, as the National Climate Assessment, the government's 1,146-page report released earlier this week states: "The rising incidence of weather extremes will have increasingly negative impacts on crop and livestock productivity because critical thresholds are already being exceeded."

Agriculture, positioned as it is at the intersection of food and climate, presents a unique fulcrum. Pushed in the direction of industrial agriculture, it contributes egregiously to our climate problem: As activist Bill McKibben has noted, industrial agriculture -- predominant in the U.S. -- "essentially insures that your food is marinated in crude oil before you eat it." This is because at every step, from the production of fertilizers and pesticides to the harvesting, processing, packaging, and transporting of materials, the industrial food system depends on climate-changing fossil fuels. Indeed, in a new report on climate change and food systems, the agriculture research organization CGIAR concluded that our global food system is responsible for nearly a third of all greenhouse gas emissions.

But we can tip the scale in the other direction toward sustainable agriculture, working in concert with natural systems instead of depleting them. This side of the scale presents an elegant, under-recognized opportunity to stabilize the climate. Not only do agro-ecological, organic and other sustainable farming methods emit significantly less greenhouse gas (GHG) overall, they can also sequester or store excess carbon. Given our long list of existing environmental worries -- erosion, polluted watersheds, dead zones in the Gulf of Mexico -- strengthening our top soil is a lot smarter than loading it up with nitrogen and washing it down the Mississippi.

Sustainable agriculture not only recaptures GHG, it eliminates the need for synthetic fertilizers like manufactured nitrogen which emits nitrous oxide. According to the EPA, agriculture is directly responsible for 68% of U.S. nitrous oxide emissions (a potent GHG; each molecule has 310 times the atmospheric warming potential of one molecule of carbon dioxide). By favoring biodiversity, productivity, resource efficiency and resilience -- sustainable agriculture also offers tangible benefits like cleaner water, preserved wildlife habitat, and reduced exposure to pesticides.

Despite these obvious advantages, sustainable systems are often dismissed as backward or as some romanticized fantasy, particularly by multi-national chemical companies with a vested interest in maintaining the industrial system. In reality these low-impact methods of farming are rooted in the realities of local climate and culture and provide promising models of resilience. Consider, for instance, Angelic Organics, a biodynamic farm in north central Illinois: it grows more than 55 different crops on 100 acres while using cover crops that sequester atmospheric carbon in the soil, harvest nitrogen from the air, protect the soil from erosion, and provide habitats for beneficial insects. Examples of such productivity combined with critical ecosystem services can be found all over the country and on every continent. Most importantly, a 2009 scientific report known as theInternational Assessment of Agricultural Knowledge, Science and Technology for Development (IAASTD) concluded that sustainable agriculture is, in fact, more resilient in the face of climate change than industrial mono-cropping -- the mile after mile of corn and soy that now dominates our farming states.

Imagine what we could do for the climate if instead of blanketing 30 percent of the nation's farmland with a single industrial crop (corn), the U.S. were to create a thriving network of rural farms and urban gardens. To tip the climate scale in our favor we need the energetic,good food movement to care as much about politics as peaches. By flexing its growing political muscle, the movement can support legislation that promotes research and training in sustainable agricultural practices. These practices mitigate climate change and put good food on our tables. Legions of young people who understand the climate change imperative are turning to agriculture. As a country we must make it as easy as possible for them to pursue careers in sustainable farming, and support them with forward-looking agriculture policies that are grounded in the climate reality of 2013.