Agriculture’s critical dependence on fossil fuels and the clearing of forests, grasslands and prairies for farming are the top two factors responsible for today’s massive global increases in CO2.

Factory smokestacks, once seen as icons of industrial progress, are now viewed with the same concern as a smoking tailpipe. Climate change has fueled an onslaught of droughts, floods and fires that have buffeted the world, killing tens of thousands and causing billions of dollars in damage. Some island nations like the Maldives are fated to see their countries swallowed by the sea. The Global Humanitarian Forum holds climate change directly responsible for 300,000 deaths a year – a figure that may need to be ratcheted upwards now that scientists have linked climate change to the increasing frequency of deadly volcanoes, earthquakes and landslides.

While an increase of 2 degrees Celsius could cause the extinction of millions of species, climate change is already threatening food yields and the livelihoods of peasant farmers around the globe. The Food and Agriculture Organization (FAO) warns that a global temperature increase of two-to-four degrees Celsius over pre-industrial levels could reduce crops yields 15-35 percent in Africa and Asia and 25-35 percent across the Middle East. When most of us think about the root causes of global warming, we think of companies like Ford, GM, Toyota, Honda, Chevron and ExxonMobil. But the problem isn’t just one of cars and smokestacks; it’s also a problem of cows and cornstalks. While governments, the media and even the some climate activists tend to focus on industry and automobiles to rein in pollution, the largest single factor stoking global warming may be the industrial food system.

Powerful corporations like Archer Daniels Midland, Cargill, Dean Foods, Dow AgroSciences, Monsanto and Tyson share a major – though largely overlooked – role in fueling climate change. These giant multinationals have seized control over much of the planet’s food resources, dominating the growing, processing and sales of meat, grains and oils. ADM and Cargill now control 65% of the world’s trade in grain. Monsanto and Syngenta control 20% of the $60-billion market in bio-engineered seeds. The corporate campaign to “patent nature” and control the world’s food supply has been so successful that today, 85% of US corn is genetically engineered.

Agriculture – at least the high-input, chemical-dependent, fossil-fueled system favored by the Agribusiness giants – has become a major part of the climate crisis. In addition to producing food and fiber, agriculture produces a harvest of three major greenhouse gasses (GHGs) – carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). Carbon dioxide is produced when fossil fuels are burned for energy and transportation and in the production of chemical pesticides and artificial fertilizers. Fertilizer manufacturing emits around 41 million metric tons of CO2 a year. Up to 60 percent of human-caused nitrous oxide (which has 296 times the Global Warming Potential of CO2) is released largely by the use of chemical fertilizers. Fifty percent of methane (with 25 times the GWP of CO2) is produced by industrial livestock operations. The impact is compounded by a global trade structure that was created to turn farming from a local enterprise into a planet-sized business.

Soils contain vast stockpiles of carbon in the form of organic matter. Industrial agriculture’s practice of plowing the land for immediate gain rather than long-term sustainability releases land-stored carbon into the atmosphere, exacerbating climate change. According to varying estimates, oil-dependent farming, livestock operations, destruction of carbon-storing fields and forests to accommodate farming, the use of chemical fertilizers and the combustion of fuel to process and distribute food all add up to between one-fifth and one-half of the human-caused pollution that is driving climate change.

The Intergovernmental Panel on Climate Change (IPCC) has warned that, in order to avoid a climate calamity, the world’s industrialized nations must cut GHG emissions 25-40% below 1990 levels by 2050. The G-77 countries and the People’s Climate Declaration have called for cutting emissions by at least 40% below 1990 levels by 2020 but neither pending US legislation nor the non-binding Accord signed at the end of the Copenhagen Climate Summit comes anywhere close to meeting this goal.

The industrialized nations are responsible for 7 of every 10 tons of CO2 emitted since the dawn of the Industrial Era – with much of that stemming from the conversion of land to large-scale commercial farming and the growth of energy- and chemical-intensive industrial agriculture. So far, the response of most of the industrialized world has been to insist that the solutions to world hunger and climate change lie in “more of the same” – agrofuels, genetically engineered “climate-ready” seeds, nuclear power, the Global Marketplace and “cap-and-trade” pollution-trading schemes. At the same time, the World Bank continues to increase its lending to fossil fuel projects around the world (up 165% in FY2008).

Fortunately, evidence is mounting that much of the damage done by industrial farming can be undone by small, local, organic farming. “If we can change the way we farm and the way we produce and distribute food,” a report from GRAIN concludes, “then we have a powerful solution for combating the climate crisis.”