Genetically modified crops and foods have advantages and disadvantages

WHAT ENVIRONMENTAL PROBLEMS ARISE FROM INDUSTRIALIZED FOOD PRODUCTION?

Food production’s harmful environmental effects

Producing food has major environmental impacts

• According to many scientists, industrial agriculture has a greater total harmful environmental impact than any human activity.

• Soil Erosion of topsoil has 2 major harmful effects.– Loss of soil fertility through depletion of plant nutrients in

topsoil. – Water pollution in nearby surface waters, where eroded

topsoil ends up as sediment.

Topsoil erosion is a serious problem in some parts of the world

Agriculture contributes to air pollution and projected climate change

• Account for more than 25% of the human-generated emissions of carbon dioxide, other greenhouse gases.

• Industrialized livestock production alone generates about 18% of the world’s greenhouse gases; cattle and dairy cows release the greenhouse gas methane and methane is generated by liquid animal manure stored in waste lagoons.

• Nitrous oxide, with about 300 times the warming capacity of CO2 per molecule, is released in huge quantities by synthetic inorganic fertilizers as well as by livestock manure.

There are limits to expansion of the green revolution

– Without huge inputs of inorganic fertilizer, pesticides, and water, most green revolution and genetically engineered crop varieties produce yields that are no higher (and are sometimes lower) than those from traditional strains.

– Clearing tropical forests and irrigating arid land could more than double the world’s cropland, but much of this land has poor soil fertility, steep slopes, or both. (plus decrease biodiversity!!!)

Meat production has problems

• Between 1961 and 2010, world meat production—mostly beef, pork, and poultry—increased more than fourfold and average meat consumption per person more than doubled.

• Global meat production is likely to more than double again by 2050 as affluence rises (China and India).

• Feedlots and CAFOs, and the animal wastes and runoff associated with them, create serious environmental impacts on the air and water.

• Such systems use large amounts of energy (fossil fuels) and water and produce huge amounts of animal waste

• Animal waste produced by U.S. meat is roughly 130 times that of its human population.

Animal feedlots and confined animal feeding operations have advantages and disadvantages

HOW CAN WE PRODUCE FOOD MORE SUSTAINABLY?

Reduce soil erosion

• Soil conservation involves using a variety of ways to reduce soil erosion and restore soil fertility, mostly by keeping the soil covered with vegetation.

• Some of the methods farmers can use to reduce soil erosion: – Terracing and contour planting are ways to grow food on

steep slopes without depleting topsoil.– Strip cropping involves planting alternating strips of a row

crop and another crop that completely covers the soil, called a cover crop.

– Polyculture (grow many crops at once on the same plot)

Soil conservation methods

Restore soil fertility

• Topsoil conservation is the best way to maintain soil fertility.

• Organic fertilizer from plant and animal materials.– Animal manure: the waste of cattle, horses, poultry, and

other farm animals adding organic nitrogen, stimulating the growth of beneficial soil bacteria and fungi.

– Green manure: consists of freshly cut or growing green vegetation that is plowed into the topsoil to increase the organic matter and humus available to the next crop.

– Compost is produced when microorganisms in soil break down organic matter in the presence of oxygen.

Restore soil fertility

• Organic agriculture uses only organic fertilizers and crop rotation to replenish the nutrients.

• Synthetic inorganic fertilizers are usually inorganic compounds that contain nitrogen, phosphorus, and potassium.– Inorganic fertilizer use has grown more than 900% since

1950; now about one-fourth of the world’s crops.

– Fertilizer runoff can pollute nearby bodies of water and coastal estuaries where rivers empty into the sea.

– They do not replace organic matter. To completely restore nutrients to topsoil, both inorganic and organic fertilizers should be used.

Produce meat more efficiently and eat less meat

• Meat production and consumption account for the largest contribution to the ecological footprints of most individuals in affluent nations.

• If everyone in the world today was on the average U.S. meat-based diet, the current annual global grain harvest could sustainably feed only about one-third of the world’s current population.

The efficiency of converting grain into animal protein varies

Shift to more sustainable food production

• Industrialized agriculture produces large amounts of food at reasonable prices, but is unsustainable because it:– Relies heavily on fossil fuels.– Reduces biodiversity and agrobiodiversity.– Reduces the recycling of plant nutrients back

to topsoil.

More sustainable, low-input food production has a number of major components

Shift to more sustainable food production

Organic farming.• Sharply reduces the harmful environmental effects of

industrialized farming and our exposure to pesticides.• Encourages more humane treatment of animals used

for food and is a more economically just system for farm workers and farmers.

• Requires more human labor than industrial farming.• Yields can be lower but farmers do not have to pay

for expensive synthetic pesticides, herbicides, and fertilizers; typically get higher prices for their crops.

Major advantages of organic farming over conventional

Shift to more sustainable food production

– Organic polyculture.• A diversity of organic crops is grown on the same plot. • Use polyculture to grow perennial crops—crops that

grow back year after year on their own.• Helps to conserve and replenish topsoil, requires and

wastes less water, and reduces the need for fertilizers and pesticides.

• Reduces the air and water pollution associated with conventional industrialized agriculture.

– Shift from using imported fossil fuel to relying more on solar energy for food production.

Ways you can eat more sustainably

Three big ideas

• About 925 million people have health problems because they do not get enough to eat and 1.1 billion people face health problems from eating too much.

• Modern industrialized agriculture has a greater harmful impact on the environment than any other human activity.

• More sustainable forms of food production will greatly reduce the harmful environmental impacts of industrialized food production systems while likely increasing food security.