Green Revolution

Revolution in agriculture productivity, resulting in huge yield increase. Two key things drove increases:

- Invention of new seeds.

- More inputs (fertilizer, pesticides, irrigation).

==> Result: Food has gotten cheaper.

Agriculture

Globalization

Food system is globalizing. Sort of. Most of the stuff produced is consumed domestically, but everyone's increasing international exports.

Environmental Consequences

Fertilizer

Vandana Shiva - "Fertilizer ... is a weapon of mass destruction". Referring to hypoxic areas (dead zones) caused by run of of fertilizer.

GHG

Agricultural Activities are a substantial greenhouse gas (GHG) emissions source.

- 20% of global greenhouse gas emissions.

BUT Without Yield Increases

We would have needed 2x the land for agriculture! That would mean "Goodbye Forests!".

Hunger Going Down

Going down, but slowing down. Also, population is increasing, so while the proportion of hungry is going down, the actual count is going up.

Food Systems and Hunger

Hunger Problem

Hunger is not a problem of production. It's a problem of distribution.

- Most hungry live in rural areas, grow their own food.

- Food systems here are thus very local.

Solution

Solution is not distribution. Instead, help the hungry people increase their productivity; not "get them more food".

Key Points

1. Globally: We see impressive production increases, driven mostly by yield improvements. (uneven progress: Asia saw improvements, Africa did not).

2. On net, these developments probably positive for environment. Without them, we'd have to cut down a lot more trees, etc. Of course, there are still environmental costs (runoff, CO2 emissions).

3. Mixed progress on hunger. Need to improve yields for poorest, not improve distribution.

Climate Change

Will depress agricultural yields in most countries in 2050, given current agricultural practices and crop varieties.

Sources of Agriculture Emissions

1) Enteric Fermentation (43%) - due to digestive system of animals

2) Manure deposited (NO2)

3) Fertilizer

GHG from Agriculture

Rising, but much slower than crop and livestock output.

GHG Emissions

Land Use Change

Declining emissions in the last 20 years.

Summary on Mitigation

What you eat and how it's grown has some effect on climate.

- Beef and other ruminants are the problem.

- Most important of all is avoiding re-expanding of agriculture.