Shifting scientific consensus are fascinating trends to follow. Mounting Evidence Suggests Early Agriculture Staved Off Global Cooling published in the University of Virginia’s UVAToday demonstrates that exact type of change.
After analyzing ice core samples for carbon dioxide levels as well as pollen deposits, researchers have found that agriculture first started affecting global climate 7,000 years ago by preventing the expected cooling cycle.
Beginning 7,000 years ago, carbon dioxide levels began rising. The author attributes this to slash and burn techniques of clearing land for farming.
Beginning 5,000 years ago, methane levels started rising which coincides with large scale rice production. My assumption is the flooding of rice paddocks caused anaerobic decomposition conditions resulting in the release of large quantities of methane which is a greenhouse gas four times as potent as carbon dioxide. The author also states that domestication of ruminants could also be a factor or it could be a combination of both rice and ruminant husbandry practices.
After 12 years of debate, the consensus is shifting to agriculture being the main cause for staving off expected cooling trends.
Samarrai, Fariss. “Mounting Evidence Suggests Early Agriculture Staved Off Global Cooling.” UVA Today. University of Virginia, 15 Jan. 2016. Web. 22 Jan. 2016.
I need to write a post on a relevant and absolutely eye-opening article published in Acres USA magazine about using soils to bank carbon. The interviewee is phD in soil sciences that explains the only way to build carbon (organic matter) permanently in soils is to keep plant roots pumping sugar into the soils to feed the symbiotic mycorrhizal fungi then leaving the soils undisturbed so the fragile humic globules are not destroyed. She asserts that all carbon from compost will eventually oxidize into carbon dioxide if plants do not constantly utilize those products of decomposition. Same goes for nitrogen in the form of off-gassing ammonia.