How Organic Food Contributes to Climate Change

scpg02 · How Organic Food Contributes to Climate Change

What are the odds the left will stop pushing organic farming do to AGW?

How Organic Food Contributes to Climate Change

By Robert Wager : BIO| 08 Aug 2007

Andre

That's a remarkable article.

An element that seems to miss is that soils should produce larger amounts of CO2 for the benefit of the plants enhancing photosynthesis with extra CO2 fertilization.

scpg02

NileQueen

And rice paddies are a source of methane!!

I think there was also a recent study where plants were found to be emitting methane...quite unexpectedly, but I'll have to double check that. Do you recall that, Andre?

scpg02

Andre

There has been some commution about plants producing methane but the latests news seems to nullify that.

Incidentily the greenhouse effect of methane is usually overexagarated. It is true that the emission spectrum of methane is larger than that of CO2 but it's in the wrong frequency area and the actual contribution of methane is small, doubled or not:

Results of MODTRAN runs comparing CO2 and CH4. The X axis is logarithmic concentration, going to unrealistic high values quickly. The Y-axis shows the increase in temperature required to restore thermal radiation balance. A process that in reality may take hundereds of years.

HighPlanesDrifter

There was an article in either Nature or Science a couple months ago touting the low carbon benefits of GM crops due to reduced tillage. If I remember correctly they made the comparison between conventional agriculture and low or no-till agriculture. (not organic v conventional)

What Robert Wager seems to miss is the fact that compared to conventional and GM techniques “Organic” farming soils are much higher in “sequestered” organic carbon in the form of humus. Some humeric acids take hundreds of years (or more) to break down. Organic farming soils may respire more CO2 than conventional soil, but they also sequester more of it. The part of the equation he leaves out is that the manure (or other organic material) would be decomposing somewhere else (possibly in anoxic conditions producing more methane if it were not reintroduced into the soil by organic techniques. Not all organic farmers rely on animal manure.

The main issue is no-till v tillage farming techniques as tilling does indeed release more soil carbon more quickly. Some organic techniques are also no or low till such as those advocated by the Biointensive folks.

It is true however that genetically modified “Roundup-ready” crops do have an inherent advantage for reducing tillage and subsequent soil carbon release.

scpg02

HighPlanesDrifter

scpg02

Probably right. I like seeing ones like Golden Rice and the sweet potato that Dr. Wambugu was creating. There are some tomatoes that are being engineered to withstand saline soil and have longer shelf life.