| You seem to leave out the results of the second study, and slightly misrepresent the numbers you state. The second study focusses on global warming potential (kg CO2 eq.). It states that Cotton bags break even with the most efficient solution "HDPE with 100% reused as bin litters" at 327 times, and "HDPE reused 3 times" at 393. The explanation of the 7.100+20.000 numbers of the first study is incomplete. They refer to ALL impact categories. Not just energy and water requirements. If we focus on the climate change impact (kg CO2), cotton breaks even at 52/149 reuses. Obvioulsly you'd have to consider the total impact at some point. Here, their methology is important. They say that: "Cotton bags are assumed to be manufactured in Europe, but the cotton used for the manufacturing is assumed to be retrieved from the market. The dataset used for cotton pro-duction (Ecoinvent, version 3.4, consequential) is based on a global average based on inputs from China, India, Latin America, and Turkey." (page 39). The cotton production should be the greatest reason for the bad environmental impact considering all impact categories. Shouldn't it? The countries listed aren't really known for their environmental friendly policies. The menufactoring process itself is just some rather simple sewing. Both studies also seem to NOT consider the environmental impact of plastic bags being thrown away. Which should be important as their aren't biodegradable. I think the overall impact of non-plastic bags leaves room for discussion/further research. Based on the global warming potentiall, cotton bags seem like a good alternative. Reuse rates of 50-400 are realistic. There are also different materials like jute or hemp where the production should be more environmentally friendly compared to cotton with similar perks (high reuse rate, biodegradable). Hanf can even be grown in Europe/NA such that there is less CO2 impact due to transport. |