Thursday, May 7, 2009

Livestock as Industry: No Way To Make it Work

I've been reading a lot about various global climate change causes and implications recently because I've been asked to talk to a local high school chemistry class about energy and sustainability. Most of what I want to talk about I can't because of time limitations. I'm going to rant here instead.

In looking at dust storm activity in the US Southwest, I came across this paper (PDF).

It discusses the impacts of multi-decadal grazing on soil properties in southeast Utah. Basically, the point is that over-grazing does a few things to the soil:
  1. It destroys the cyanobacteria, lichens, and mosses in the upper part of the soil. This causes loss of nitrogen in the soil. As you all know, nitrogen fixing is necessary for the generation of proteins and DNA, and is therefore necessary for life. When the nitrogen fixing stops, the soil loses its life-sustaining capabilities. Nitrogen levels in the grazed soils vs. the ungrazed soils was 60-70% less.
  2. Carbon, another essential ingredient for life is decreased by 60-70% as well.
  3. The loss of life on these soils allows wind erosion to increase dramatically, which reduces the amount of Mg, Na, P, and Mn by 14-51% (different for the different elements).
  4. Silts are decreased by 38-43%.
Basically, nutrients of all kinds are lost from these grazed lands. It's been 30 years since the last cow was grazed there, and the lands have not recovered; cyanobacteria takes at least 100 years to recover.

What does this mean for climate change? Well, for one, the loss of nutrients to erosion makes the drylands of Utah more sensitive to small variations in moisture variability. What was once considered a dry spell will be a drought. Higher sensitivity to rainfall will also quickly cause decreases in plant life. Plants, bacteria, mosses, lichen, etc. are what keep the nutrients available to...feed life. A decrease in one causes a positive feedback loop that eventually causes a loss of both.

What happens once the plant life is mostly gone? Winds remove the nutrients. You get massive dust storms as seen here. So, what? It's just a little wind, it's not like that has ever hurt anyone.

So what happens is you get this:

Aww... The poor skiiers have to ski on dirty snow. So, what?

Dirty snow is darker snow. Darker snow absorbs more sunlight and melts earlier. Early melting of snow can have many affects, but most importantly, it changes the timing of when meltwater is available to downstream plants and animals. If the plants are not yet ready to receive the water, they'll die off.

Here's a great article on how changing climate and specifically changing of timing in the climate affects creatures in differing ways. Go read it now. I'll wait. Seriously. Go!

Basically, it turns out that some plants and animals time their various activities based on temperature while others time their activities on available sunlight. So, some creatures/plants will peak earlier than they used to while their migratory predators show up late to the party because their sunlight- or other time-based clocks are out of sync with the climate.

Early meltwater running (and necessarily less on-time meltwater) will dramatically affect the creatures that depend on it and the creatures that depend on them, and the creatures that depend on... ad nauseum.

So, can't they just evolve to deal with it? Sure, if they have several tens of thousands of years.

This is the entire problem with human-induced climate change. Things are changing too quickly for most life to adapt. Sure, eventually it'll figure itself out, with likely only a few surviving species and a few new, unrecognizable species, but it's going to be a bleak, bleak place if we don't get our heads out of our asses soon.

2 degrees C of warming is going to push us to the tipping point with no room for error after that; we have less than a decade to figure that out and to do something about it.

What does all of this have to do with livestock? They're unsustainable. The only way eating beef makes sense is if you own 80 or 100 acres of grassland (that's nowhere in the southwest--those are not grasslands, they're drylands.) and have a single cow and calf. Then, it still doesn't make sense to eat the cow when you can get dairy from it. Eating beef from large (in number of head) ranches doesn't make sense at all, whether they're grassfed or cornfed. Grazing livestock (beef) in the way we've been doing for the last 100 years or so is simply not sustainable and it is killing the drylands of the mid- and southwest.


Jennifer said...

I've read on a couple of "how to go green" websites the suggestion to try going one day without eating meat. Americans tend to eat meat based meals for every meal of the day so people consider going without a hardship. This is amusing to me. Once you start thinking outside the hamburger box, it's not hard at all to do with a little less meat during the week. And if everyone would do this, the positive impact on the environment could be impressive!

Debbie said...

I don't think it would hurt any of us to eat a little more fruit and vegetables....and it has a lot of positive effects for good health and weight control which seems to be a concern for many.