Soybean boom spells bad news for climate - New Scientist

[Eugene]

Source: New Scientist

Soybean boom spells bad news for climate
21 April 2007
From New Scientist Print Edition.
Kate Ravilious

CHOPPING down the Amazon rainforest to plant soybean crops is more
detrimental to the climate than clearing space to graze cows. Fields
of soybean reduce rainfall dramatically, over four times as much as
pastureland.

Around 13 per cent of the original Brazilian rainforest has been cleared
so far, with 85 per cent turned into pasture and 15 per cent into
soybean fields. However, these plantations are rapidly expanding
thanks to soya's popularity as a food and suitability as a biofuel.

To measure how different land use affects climate, Marcos Costa from
the Federal University of Viçosa in Brazil, and colleagues, measured
changes in albedo or reflectivity over experimental plots of soybean
and pastureland. They then plugged the data into a climate model to
investigate the effect of the change in land use.

-snip-

Read more: http://environment.newscientist.com/channel/earth/climate-change/mg19426004.800-soybean-boom-spells-bad-news-for-climate.html

[Dervill Crow]

1. Crap, and here I thought I was helping the environment and animals by using soy.

Can't win from losing.

So what do you know about rice?

[jpak]

4. The vast majority of Brazilian soy production is exported to Europe for livestock feed

Very little is used for people food - you *are* doing the right thing BTW...

:hi:

[hughee99]

2. So soy reduces rainfall, but also does not produce methane

like cows do. Which is more harmful to the climate?

[Eugene]

3. Soy is expanding like crazy and is driving a new wave of deforestation.

Soy production is driving and funding new road building in the Amazon.
Cutting down (and burning) the forests for soy releases large amounts
of CO2.

While methane is a more powerful GHG, efforts to control emissions
are progressing much faster than those for CO2.

[hughee99]

5. As I read it, the argument seems to be that

basically an acre of soy was worse than an acre of pasture. If that's the argument, then this would have nothing to do with new road building or cutting down trees since you would have to do that for either land use.

[Eugene]

6. Soy is the big money maker now and it is driving the growth.

Soy is the minority land use, but it is growing fast
as more and more forest is cut down. The soy export
business is also driving the demand for better roads.
Big soy producers have been driving deforestation
for a long time now.

Earlier this week: The long road to ruin for the Amazon forest - The Observer

Some more background: Brazil Shuts Down Cargill's Amazon Port - AP

[hughee99]

7. I understand that Soy is driving the growth,

but the study isn't really about growth. It seems to me to be saying "given X amount of land, the climate is more damaged by growing soy than it would be as a cow pasture"

From the article:
"CHOPPING down the Amazon rainforest to plant soybean crops is more detrimental to the climate than clearing space to graze cows. Fields of soybean reduce rainfall dramatically, over four times as much as pastureland."

What I'm wondering is whether they're just doing this comparison based on the albedo of the land itself, or if they're also taking into account the methane that cows produce. Is the overall negative climate affect of the methane from cows more, less, or about equal to the reduction in rainfall seemingly caused by soy?

[Eugene]

8. Methane may not figure into drying.

Anyhow as the rest of the article says. They observed an almost 16% drop in rainfall
for land mostly cleared for soy vs. a near 4% drop on land mostly cleared for pasture.
Drying out the rainforest climate contributes its own damage on top of warming.