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First of all, a large portion of that graph refers to methane not carbon dioxide. Methane has a half life of 10 years, as compared to carbon dioxide's thousands

First of all, a large portion of that graph refers to methane not carbon dioxide. Methane has a half life of 10 years, as compared to carbon dioxide's thousands or tens of thousands. Also take care to inspect, carefully, what these figures represent. This graph only counts transportation of final food product to stores under the "transportation" category: "Emissions from energy use in the transport of food items". In other words, the emissions from taking the packets of meat from a slaughterhouse to grocery store shelves. Not shipping loads of grain to ranches. The actual article [1] this image comes from explains this more clearly, "Food transport accounted for only 5% of this. This means that if we were to take the case where we assume a household sources all of their food locally, the maximum reduction in their footprint would be 5%". Transportation of feed to ranches is categorized under feed, not transportation. This is why estimates for the amount of carbon emissions meat is responsible often vary by a large margin. Some place meat, alone, as responsible for 14-19% of emissions. Others place all food production (not just meat) as under 5%. It largely depends on whether you include things like transportation, nitrogen fixing via the haber process, and land conversion under the umbrella of food production or in their own separate categories. 1. https://ourworldindata.org/food-choice-vs-eating-local https://ourworldindata.org/food-choice-vs-eating-local

smokey_circles 6y ago
I disagree, going so far as to call this intentionally obtuse or misinformed. 1. CO2 is not the sole measure of environmental impact. The land usage problem is also pretty serious. Deforestation chief among it. 2. I can't find any literature to back up the claim that CO2 has an atmospheric residency of thousands of years, seems to be 100 at best estimates [0] 3. Over that 100 year period, Methane has 25x greater effect than CO2 [1] 4. Methane oxidises into CO2 and H20, so transport is still not the greatest contributor [0] https://scholars.unh.edu/cgi/viewcontent.cgi?httpsredir=1&article=1605&context=earthsci_facpub https://scholars.unh.edu/cgi/viewcontent.cgi?httpsredir=1&ar... [1] https://unece.org/challenge https://unece.org/challenge
- manfredo 6y ago
  1. Land use for agriculture is going down in the US [1], as with most developed countries. Factory farming is more intensive per acre, leading to fewer. Likewise forests in Europe are expanding [2]. Industrialized agriculture leads to less land cultivated because of its greater production per unit of land. Much of the land used for agriculture today was deforested over 70 years ago. 2. NASA puts the estimate at 300-1000 years [3], but it looks like this includes carbon sequestration as one of the decay methods not decay in the atmosphere like methane. Absent sequestration, carbon dioxide lasts a lot longer. 3 & 4. While methane has greater short term effect, the total amount of methane being released is orders of magnitude less. About 2.5 ppm of carbon dioxide is added each year, as compared to methane's 5-7 ppb added each year. Note the difference in units, parts per million versus parts per billion. Sure it's 25x greater impact, but it's emitted 500x less and decays 30-100x faster. That's why methane's contribution to thermal imbalance is relatively static while carbon dioxide's is increasing [4]. Carbon dioxide is overwhelmingly the cause of climate change. 1. https://www.ers.usda.gov/amber-waves/2017/december/a-primer-on-land-use-in-the-united-states/ https://www.ers.usda.gov/amber-waves/2017/december/a-primer-... 2. https://www.weforum.org/agenda/2019/07/forest-europe-environment/ https://www.weforum.org/agenda/2019/07/forest-europe-environ... 3. https://climate.nasa.gov/news/2915/the-atmosphere-getting-a-handle-on-carbon-dioxide/ https://climate.nasa.gov/news/2915/the-atmosphere-getting-a-... 4. https://www.climate.gov/news-features/understanding-climate/climate-change-annual-greenhouse-gas-index https://www.climate.gov/news-features/understanding-climate/...

smokey_circles 6y ago

I disagree, going so far as to call this intentionally obtuse or misinformed. 1. CO2 is not the sole measure of environmental impact. The land usage problem is also pretty serious. Deforestation chief among it. 2. I can't find any literature to back up the claim that CO2 has an atmospheric residency of thousands of years, seems to be 100 at best estimates [0] 3. Over that 100 year period, Methane has 25x greater effect than CO2 [1] 4. Methane oxidises into CO2 and H20, so transport is still not the greatest contributor [0] https://scholars.unh.edu/cgi/viewcontent.cgi?httpsredir=1&article=1605&context=earthsci_facpub https://scholars.unh.edu/cgi/viewcontent.cgi?httpsredir=1&ar... [1] https://unece.org/challenge https://unece.org/challenge

manfredo 6y ago
1. Land use for agriculture is going down in the US [1], as with most developed countries. Factory farming is more intensive per acre, leading to fewer. Likewise forests in Europe are expanding [2]. Industrialized agriculture leads to less land cultivated because of its greater production per unit of land. Much of the land used for agriculture today was deforested over 70 years ago. 2. NASA puts the estimate at 300-1000 years [3], but it looks like this includes carbon sequestration as one of the decay methods not decay in the atmosphere like methane. Absent sequestration, carbon dioxide lasts a lot longer. 3 & 4. While methane has greater short term effect, the total amount of methane being released is orders of magnitude less. About 2.5 ppm of carbon dioxide is added each year, as compared to methane's 5-7 ppb added each year. Note the difference in units, parts per million versus parts per billion. Sure it's 25x greater impact, but it's emitted 500x less and decays 30-100x faster. That's why methane's contribution to thermal imbalance is relatively static while carbon dioxide's is increasing [4]. Carbon dioxide is overwhelmingly the cause of climate change. 1. https://www.ers.usda.gov/amber-waves/2017/december/a-primer-on-land-use-in-the-united-states/ https://www.ers.usda.gov/amber-waves/2017/december/a-primer-... 2. https://www.weforum.org/agenda/2019/07/forest-europe-environment/ https://www.weforum.org/agenda/2019/07/forest-europe-environ... 3. https://climate.nasa.gov/news/2915/the-atmosphere-getting-a-handle-on-carbon-dioxide/ https://climate.nasa.gov/news/2915/the-atmosphere-getting-a-... 4. https://www.climate.gov/news-features/understanding-climate/climate-change-annual-greenhouse-gas-index https://www.climate.gov/news-features/understanding-climate/...