Agriculture & its impact to Global warming!

11 JUN, 2014
by Bikash Mohanty

When we think about threats to the environment, we tend to picture cars and smokestacks, not food. But the truth is, our need for food poses one of the biggest dangers to the planet.

Agriculture is among the greatest contributors to global warming, emitting more greenhouse gases than all our cars, trucks, trains, and airplanes combined — largely from methane released by cattle and rice farms, nitrous oxide from fertilized fields, and carbon dioxide from the cutting of rain forests to grow crops or raise livestock. Farming is the thirstiest user of our precious water supplies and a major polluter, as runoff from fertilizers and manure disrupts fragile lakes, rivers, and coastal ecosystems across the globe. Agriculture also accelerates the loss of biodiversity. As we’ve cleared areas of grassland and forest for farms, we’ve lost crucial habitat, making agriculture a major driver of wildlife extinction.

The environmental challenges posed by agriculture are huge, and they’ll only become more pressing as we try to meet the growing need for food worldwide. We’ll likely have two billion more mouths to feed by mid-century—more than nine billion people. But sheer population growth isn’t the only reason we’ll need more food. The spread of prosperity across the world, especially in China and India, is driving an increased demand for meat, eggs, and dairy, boosting pressure to grow more corn and soybeans to feed more cattle, pigs, and chickens. If these trends continue, the double whammy of population growth and richer diets will require us to roughly double the amount of crops we grow by 2050.

Unfortunately the debate over how to address the global food challenge has become polarized, pitting conventional agriculture and global commerce against local food systems and organic farms. The arguments can be fierce, and like our politics, we seem to be getting more divided rather than finding common ground. Those who favour conventional agriculture talk about how modern mechanization, irrigation, fertilizers, and improved genetics can increase yields to help meet demand. And they’re right. Meanwhile proponents of local and organic farms counter that the world’s small farmers could increase yields plenty—and help themselves out of poverty—by adopting techniques that improve fertility without synthetic fertilizers and pesticides. They’re right too.

But it needn’t be an either-or proposition. Both approaches offer badly needed solutions; neither one alone gets us there. We would be wise to explore all of the good ideas, whether from organic and local farms or high-tech and conventional farms, and blend the best of both.

How can the world double the availability of food while simultaneously cutting the environmental harm caused by agriculture? After analyzing reams of data on agriculture and the environment, scientists have proposed five steps that could solve the world’s food dilemma.

  • Step One       : Freeze Agriculture’s Footprint
  • Step Two      : Grow More on Farms we’ve got
  • Step Three   : Use Resources More Efficiently
  • Step Four     : Shift Diets
  • Step Five      : Reduce Waste

For most of history, whenever we’ve needed to produce more food, we’ve simply cut down forests or plowed grasslands to make more farms. We’ve already cleared an area roughly the size of South America to grow crops . To raise livestock, we’ve taken over even more land, an area roughly the size of Africa. Agriculture’s footprint has caused the loss of whole ecosystems around the globe, including the prairies of North America and the Atlantic forest of Brazil, and tropical forests continue to be cleared at alarming rates. 

Starting in the 1960s, the green revolution increased yields in Asia and Latin America using better crop varieties and more fertilizer, irrigation, and machines—but with major environmental costs. The world can now turn its attention to increasing yields on less productive farmlands—especially in Africa, Latin America, and Eastern Europe —where there are “yield gaps” between current production levels and those possible with improved farming practices. 

We already have ways to achieve high yields while also dramatically reducing the environmental impacts of conventional farming. The green revolution relied on the intensive—and unsustainable—use of water and fossil-fuel-based chemicals. 

It would be far easier to feed nine billion people by 2050 if more of the crops we grew ended up in human stomachs. Today only 55 percent of the world’s crop calories feed people directly; the rest are fed to livestock (about 36 percent) or turned into biofuels and industrial products (roughly 9 percent).

An estimated 25 percent of the world’s food calories and up to 50 percent of total food weight are lost or wasted before they can be consumed.