Fight global warming with MORE cattle?
Mar 5, 2013
I just finished watching Allan Savory's talk at TED: http://www.ted.com/talks/allan_savory_how_to_green_the_world_s_deserts_and_reverse_climate_change.html In it he proposes using rotational grazing to reverse desertification and global warming. What do you think?
Mar 14, 2013
Allan's approach is fundamentally sound, and I love it. I have promoted his approach for the past ten years. So I'm 100% supporting Allan's work. HOWEVER, this is one small slice of the host of solutions that are needed to tackle climate change. This method does not have the ability, as Allan claims, to reduce the planet's overburden of atmospheric carbon to 280 parts per million. We have an excess of 250 gigatonnes of carbon in the atmosphere: we're currently at 840 Gt, and we need to get back to 590 Gt, the equivalent of 280 parts per million of CO2. We are adding 10 Gt a year, of which 5 Gt is accumulating in the atmosphere (5 Gt in the oceans). The data for increased soil carbon storage in the grasslands suggests that planned rotational grazing could store max 6 Gt of carbon a year. If we were to cease burning all fossil fuels and cease destroying all tropical forests tomorrow morning, this 6 Gt annual withdrawal could (purely mathematically) reduce the 840 Gt back to 590 in 42 years. However, 6 Gt is the max, and 1.5 Gt a year is more realistic, and meanwhile, we're still adding 5 Gt a year to the atmosphere. So please don't walk away thinking that this is an easy fix for climate change. It's one of a hundred similar solutions. Allan's claim that a billion hectares of Afrtica are being lost to fire every year is also wrong, as Chris Hounsome says below. In Bethesda Maryland, where Martha Holdridge has been using management intensive grazing, soil testing by West Virginia State University demonstrated a five-year increase in soil carbon content in the top two inches from 4.1% to 8.3%, storing an additional 4 tons of carbon per acre over five years (1.8 tonnes per hectare per year). If this could be replicated on 3.4 billion hectares of grassland, it could sequestrate 6 billion tonnes (6 Gt) of carbon a year. http://soilcarboncoalition.org/opportunity and http://soilcarboncoalition.org/calculation