Cowboys can save the planet!!!

I cannot view the video, so I comment on Chuck's summary. Whether cows have positive or negative effects have a lot to do with the stocking density and (rather small) variations in rainfall.

In the late 19th century, cattle grazing increased desert areas. Perhaps that was limited to areas to the west of those discussed here. Anyway, you can google scholar

desertification desert grassland

to see some research on the topic.

 

Tochatihu maybe you can view these videos.He says grazing herds stop desertification.

2009 Feasta Annual Lecture

 

Amazing.
This Man Shot 40,000 Elephants Before He Figured Out That Herds Of Cows Can Save The Planet | Co.Exist: World changing ideas and innovation

"For a long time, experts blamed desertification on over-grazing. And in Africa, where Savory was working on national parks, he blamed elephants. So they started culling them, eventually killing 40,000 of the animals (this was back when you could kill elephants with impunity).
But killing the elephants didn’t work."

 

I nominate him for the Idiot /Savant award.
Lets hope hes got it right .

 

TED talks generally feature pretty smart people. But the synopsis above makes this guy sound ... not very smart. I believe that's because the synopsis doesn't accurately reflect the gist of what he says.

1) He starts by saying that fossil fuel is isn't the only driver of climate change. That the loss of carbon stored in soils adds to it. "Fossil fuels ... are by no means the only thing that is causing climate change."

That's completely true.

Only later, in the windup, does he say that desertification is causing as much climate change as other source, but that is firmly qualified with "I believe". He can believe what he wants, but that's not what the best available evidence shows. Land use changes account for maybe 10% of the overall climate forcing.

2) Here's the story. In grasslands with only seasonal moisture, if the tall grass is allowed to stand, it eventually stifles new growth. You can burn if off, but it's better to graze it in a particular fashion. Not with a spread-out, static herd. He requires bunched herds of moving cattle that stamp the grass down into the soil, so it decays. So that the cattle herds mimic the behavior of the wild animals that would otherwise have occupied those grasslands.

So, to be clear, he doesn't say, graze cattle. He says, graze cattle in a specific way that mimics wild herds. That means bunched together and moving. This stomps the grass into the soil and improves overall productivity of the soil.

He seems to have excellent evidence to support this, and this form of land management appears to be becoming the norm in parts of Africa.

3) To clarify for others, he's not talking about desertification caused by climate change, he's talking about desertification caused by current land management practices. So this is land that has adequate seasonal moisture to support grasslands. By not planning the grazing to mimic nature, it encourages the grassland to convert to desert, per 2) above.

4) He says that if you converted half the grassland in the world to his grazing system, it would sequester enough carbon to reach pre-industrial levels of atmospheric CO2. Emphasis there is on sequestering carbon, not on some unspecified mechanism. So that's very mainstream. I doubt that the magnitude is correct, but I'm not going to take the time to look it up.

The upshot is, this guy figured out that, for grasslands with seasonal moisture, if you prevent grazing, you encourage desertification, because the standing dead grass stifles growth. That's contrary to (what used to be) the convention wisdom. He says (and fairly clearly demonstrates) that, in the right climate, you get much higher land productivity, and carbon sequestration, if you graze livestock in a specific fashion that mimics the behavior of wild herds. His assertion that land use changes are as important as other drivers of climate change is not supported by any source I know of. His assertion that employing his system on half the grassland in the world would sequester enough carbon to get to pre-industrial levels seems far higher than any other estimate I've seen of sequestration potential in grasslands, but I'm not going to look up the data.

 

This, and the associated thread with link to Savoy's TED talk covers a very interesting topic. In fact he shows the place where I did MS research (Jornada) and comes to the opposite conclusion from 'the leaders' there.

I try to keep an open mind where non-conventional science is involved. Because nearly any level of scientific understanding is subject to be overturned by new findings.

There is no reason at all to oppose experiments to test this. There may be reason to be cautious about extrapolating to much larger scales of time and space. Ideally, it would be taken up by people who realize that water cannot evaporate more than about 1 cm per day, that non-human-caused fires are recurrent in seasonally dry grasslands, that grazing animal traffic substantially reduces hydraulic conductivity of soils (except where they are dominated by clay), that termites eat the dry grass, and several other things that I do not hear about in Savoy's TED. I have not viewed the 1-hr Feasta; perhaps he talks about such things here.

So, proceed with the demonstrations by all means. Just keep in mind that an empirical demonstration by itself does not overturn scientific principles. It can only demonstrate that that our understanding of them is incomplete.

 

A recent paper:

The role of land use change in the recent warming of daily extreme temperatures
Nikolaos Christidis, Peter A. Stott, Gabriele C. Hegerl, and Richard A. Betts
GEOPHYSICAL RESEARCH LETTERS, VOL. 40, 1–6, doi:10.1002/grl.50159, 2013

Touches on the idea. As grassland area have increased and forest decreased, extreme temperatures are moderated. This is an 'attribution' question; among the most vexing that we now face.

The question is whether grass has deeper roots than forest trees, getting that water back upstairs where latent heat exchange can happen. Y'all will be most disappointed to learn that ecologists haven't yet a clear handle on that.

Now, annual grasses in the desert transition are not deep rooting, but I am in no position to rule out their climate wonderfulness. I am like a climate skeptic except (a) I read the literature and (b) I happily accept the possibility that I may be wrong about stuff.

So, let Savoy's experiments continue and extend to other regions. Let's see how it goes in the face of high decadal rain variability that characterizes the grassland/desert transition.

 

I'm not even sure what is controversial. In a healthy ecosystem Grazers eat and fertilize the vegetation. Get rid of the grazers, and the system becomes less healthy. Too many grazers, the vegetation is over grazed, plants are destroyed and then there is less food, killing some of the grazers. In texas with high weather variability, there have been long periods of feast and famine. 2011 was a famine drought year. Ranchers could buy feed - grain to supplement the grasses, or cull the heard, sell the meat before the animals started to starve. The big negative on texas was the lumber industry in the 1800s to early 1900s cutting down trees, to set up farms and sell the timber. This has been corrected, and tree farms are now rotated. It doesn't fix the damage done. Cattle are less destructive than sheep or goats. Factory meat farming is the most destructive of all for the environment, and the least humane, but it keeps meat prices lower and grain prices high, something that appears to be US government policy.