Organic cotton is ahead of plastic for greenhouse gases after 149 uses. That's a small number of uses for a cotton tote bag, which should last several years of daily wear. That means that from the 150th use you are reducing greenhouse gases every time you take the bag out, while potentially still net polluting in a couple of other ways.

But greenhouse gas emissions are by far the most critical and potentially catastrophic environment issue. If we can effectively and reliably lower greenhouse gases while causing a few extra rhino deaths or depleting the ozone layer marginally, we should enthusiastically seize that opportunity.

Given this, the "average over all pollution types" seems particularly useless and intentionally misleading here. That number literally cannot be coerced into meaning anything that should affect your decision making process.

Who uses it every day? My trips to get groceries are every week or two weeks. I'd have a decent chance of misplacing the thing before I offset its carbon. If I forgot it just once and had to turn the car around to get it I'd probably double its footprint.

There are 52 weeks in a year. After several years of weekly use you have offset the carbon.

> I'd have a decent chance of misplacing the thing before I offset its carbon.

You can keep things simply and only use it for groceries if you have trouble keeping track of things. Keep it in the same location every time, ideally by the door, always return it to it's spot immediately after unloading groceries when you get home. Don't leave a full bag of groceries at the store. You're pretty much set.

You could also go for a recycled PET reusable bag if you just can't trust yourself to hang on to a cotton bag for a few years. Still better than single-use plastics by many metrics as long as you aren't losing bags multiple times per year. And yeah, don't turn around to get your bag when you're halfway to the store; get single-use plastic on that occasion and spend a few moments gently reaffirming your habit/routine that includes grabbing the bag when you head out for groceries.

Is it a small number? I put my bags in my shopping cart so I always wash them after each use since the carts are unsanitary. Once you start washing them after each use, the bags fall apart rather quickly. It might not be less than 149 uses, but I wouldn't be surprised if it was.