Livestock populations have long been vilified as major culprits behind desertification. But one scientist believes the animals could actually be used to heal some of the world's most degraded landscapes.

Desertification is a phenomenon that occurs when in a stretch of already dry land becomes so barren that the ground is no longer able to absorb rainwater. This soil becomes unproductive — which may limit the planet's farmable land — and it also becomes incapable of safely storing carbon dioxide, meaning more CO2, a greenhouse gas, gets released back into the atmosphere.

Biologist Allan Savory explained in a talk at the TED 2013 conference in Long Beach, Calif., last month that he was taught to hold livestock accountable for incurring such damage on the land, since overgrazing strips the Earth of vegetation. And in Africa, where he was working to set up national parks in the 1950s, Savory thought elephants were also to blame for the land's deterioration. Savory said his research led to the shooting of 40,000 elephants, but the damage only got worse.

"Loving elephants as I do, that was the saddest and greatest blunder of life, and I will carry that to my grave," Savory told the audience.

"One good thing did come out of it: It made me absolutely determined to devote my life to finding solutions."

Turning course, Savory now believes that the only option left to combat desertification is "to use livestock, bunched and moving, as a proxy for former herds and predators and mimic nature."

He argues that Earth's soil and vegetation developed alongside very large numbers of grazing animals, which traveled in packs, were constantly moving — sometimes quite frantically when being chased by predators — and left a natural layer of fertilizer in the form of droppings.

"It was that movement that prevented the overgrazing of plants while the periodic trampling ensured good cover of the soil," Savory said.

Savory has worked with communities to implement a holistic style of grazing that attempts to mimic this process. It involves keeping cattle in dense herds and moving them frequently so that the land is not overused and the soil becomes productive, retaining water instead of letting it evaporate or run off in floods.

The Savory Institute, which he founded, and its sister organization, the Africa Center for Holistic Management, are leading these efforts. Savory says his methods are being are being practiced on 15 million hectares across five continents.

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