Ancient technique eyed to cut greenhouse gases

December 6, 2008

Poland (ChattahBox) — An ancient technique of plowing charred plants into the ground to revive soil may also trap greenhouse gases for thousands of years and forestall global warming. Pre-Columbian Amazonian Indians used it to enhance soil productivity and made it by smoldering agricultural waste. Plants absorb carbon dioxide from the atmosphere as they grow. Subsequently storing that carbon in the soil removes the gas from the atmosphere.

Heating plants such as farm waste or wood in airtight conditions produces a high-carbon substance called biochar, can store the greenhouse gas carbon dioxide and enhance nutrients in the soil. The ancient method for producing biochar as a soil additive was the “pit” or “trench” method, which created terra preta, or dark soil. While this method still has potential to produce biochar in rural areas, it does not allow the harvest of either the bio-oil or syngas, and releases a large amount of CO2, black carbon, and other GHGs (and potentially, toxins) into the air. Modern companies are producing commercial-scale systems to process agricultural waste, paper byproducts, and even municipal waste.

The International Energy Agency (IEA) said in November that global greenhouse gas emissions were so out of control and that avoiding more dangerous levels of climate change depended on creating negative emissions later this century. The energy adviser to 28 industrialized countries cited biochar as one way of achieving that.

Under ambitious scenarios biochar could perhaps store 1 billion tons of carbon annually, equivalent to more than 10 percent of global carbon emissions, which amounted to 8.5 billion tons in 2007. Under a more conservative scenario the technique could store 0.2 billion tons of carbon annually. That would still require heating without oxygen — called pyrolysis — some 27 percent of global crop waste and plowing this into the soil. Experiments also suggest biochar can also increase yields by up to three times, because the organic matter holds on to nutrients.

Soils containing biochar made by Amazon people thousands of years ago still contain up to 70 times more black carbon than surrounding soils and are still higher in nutrients, said Debbie Reed, director of the International Biochar Initiative (IBI). The IBI was in Poznan to lobby for research funding for biochar. In Poznan, 187 countries are meeting in ongoing talks to agree a new climate treaty to replace the Kyoto Protocol after 2012. They hope to finalize a deal next year. The technique however is not a substitute for fighting climate change by curbing man-made greenhouse gas emissions, especially carbon dioxide from burning fossil fuels.

The technique does ring alarm bells though among some environmentalists worried it could spur deforestation, but its chief problem may be that it is barely proven on a commercial scale.


One Response to “Ancient technique eyed to cut greenhouse gases”

  1. Erich J. Knight on December 7th, 2008 1:22 am

    Biochar, the modern version of an ancient Amazonian agricultural practice called Terra Preta (black earth), is gaining widespread credibility as a way to address world hunger, climate change, rural poverty, deforestation, and energy shortages… SIMULTANEOUSLY!

    Modern Pyrolysis of biomass is a process for Carbon Negative Bio fuels, massive Carbon sequestration,10X Lower Methane & N2O soil emissions, and 3X Fertility Too.
    Every 1 ton of Biomass yields 1/3 ton Charcoal for soil Sequestration, Bio-Gas & Bio-oil fuels, so is a totally virtuous, carbon negative energy cycle.

    Charles Mann (“1491”) in the Sept. National Geographic has a wonderful soils article which places Terra Preta / Biochar soils center stage.
    I think Biochar has climbed the pinnacle, the Combined English and other language circulation of NGM is nearly nine million monthly with more than fifty million readers monthly!
    We need to encourage more coverage now, to ride Mann’s coattails to public critical mass.

    Please put this (soil) bug in your colleague’s ears. These issues need to gain traction among all the various disciplines who have an iron in this fire.

    I love the “MEGO” factor theme Mann built the story around. Lord… how I KNOW that reaction.

    I like his characterization concerning the pot shards found in Terra Preta soils;

    so filled with pottery – “It was as if the river’s first inhabitants had
    thrown a huge, rowdy frat party, smashing every plate in sight, then
    buried the evidence.”

    Biochar data base;

    I also have been trying to convince Michael Pollan ( NYT Food Columnist, Author ) to do a follow up story, with pleading emails to him

    Since the NGM cover reads “WHERE FOOD BEGINS” , I thought this would be right down his alley and focus more attention on Mann’s work.

    I’ve admiried his ability since “Botany of Desire” to over come the “MEGO” factor (My Eyes Glaze Over) and make food & agriculture into page turners.

    It’s what Mann hasn’t covered that I thought should interest any writer as a follow up article and your transition team

    The Biochar provisions by Sen.Ken Salazar in the 07 & 08 farm bill,

    NASA’s Dr. James Hansen Global warming solutions paper and letter to the G-8 conference, placing Biochar / Land management the central technology for carbon negative energy systems.

    The many new university programs & field studies, in temperate soils; Cornell, ISU, U of H, U of GA, Virginia Tech, New Zealand and Australia.

    Glomalin’s role in soil tilth, fertility & basis for the soil food web in Terra Preta soils.

    The International Biochar Initiative Conference Sept 8 in New Castle;

    Given the current “Crisis” atmosphere concerning energy, soil sustainability, food vs. Biofuels, and Climate Change what other subject addresses them all?

    This is a Nano technology for the soil that represents the most comprehensive, low cost, and productive approach to long term stewardship and sustainability.

    Carbon to the Soil, the only ubiquitous and economic place to put it.

    Michael Pollan is well briefed about Biochar technology, but did not include it in his 8000 word, “Farmer & Chief” NYT’s article to President Obama, but I’m sure Biochar will be his 8001th word to you.

    540 289 9750

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