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I find it hard to believe that you read the entire section on environmental impact, let alone the paper, if that single sentence in that section is all you coul
by jcranberry 5y ago
I find it hard to believe that you read the entire section on environmental impact, let alone the paper, if that single sentence in that section is all you could find. The quote from the press article does not disagree with what the paper says.
"The evidence suggests that organic agriculture uses less energy per unit of land, and to a lesser extent, also per unit of output than conventional agriculture (Table 3). This difference is mainly attributable to the nonuse of synthetic fertilizers and pesticides in organic systems. Fuel use for agricultural operations is similar across systems. However, for certain crops (especially vegetables) more fuel is sometimes required in organic production, when repeated mechanical or thermal weed control becomes necessary (Lynch et al. 2011, Scialabba & Müller-Lindenlauf 2010, Smith et al. 2015). This may also lead to higher overall energy use in organic systems in certain situations (Lee et al. 2015).
"Concerning GHG emissions, most studies conclude that organic farming has lower impacts when expressed per unit of land but not when expressed per unit of output (Table 3). Generally, organic systems are characterized by lower nitrogen inputs, and thus lower N2O emission potential. However, balancing nutrient supply and plant demand is typically more challenging in organic systems; oversupply of nitrogen from organic fertilizer may also lead to significant N2O emissions, while undersupply leads to lower yields (Clark & Tilman 2017, Lynch et al. 2011, Skinner et al. 2014). In crop production, soil carbon stocks and sequestration rates were found to be significantly higher in organic than in conventional systems (Gattinger et al. 2012, Lori et al. 2017). In livestock production, less intensive organic husbandry systems lead to larger quantities of manure per unit of meat, and thus higher methane and N2O emissions (Treu et al. 2017). Overall, the evidence does not support the widely held notion that organic agriculture is more climate friendly than conventional agriculture (WBA 2016)."
Unfortunately that last citation is some 500 page document in German which I'm unable to read.
- guerby 5y agoDid you really read table 3? Per output organic vs conventional: Energy use 15–21% lower a,b Nitrous oxide emissions 8% higher a GHG emissions 0–10% lower a,b,c GHG emissions of organic diet equal to conventional diet d One 2012 paper (I did not track it) says nitrous oxide higher 8% but GHG less up to 10% or identical, so less air pollution overall. For reference Nitrous oxide is around 7% of all GHG in the USA, so the +8% by 70% by 7% doesn't amount to much vs 0-10% when you add up, source: https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emis...
- jjoonathan 5y agoWhat is the rationale for calculating relative impacts per acre instead of per unit output? This appears like a hustle to make organic agriculture look better than it is. I am prepared to be wrong about that, of course. It isn't completely beyond the realm of possibility that there are legitimate "dilution is the solution to pollution" effects at play. I just... have doubts.