They're starting off by replacing a potentially renewable resource (trees) with two nonrenewable resources (plastic and limestone). It could still come out ahead in the lifecycle analysis, but it's not a great place to start.

>and are fully recyclable

How about after mixing them with a bunch of limestone? Generally "hybrid" materials aren't recyclable (tetrapacks, mylar bags, wet strength cardboard, etc).

Serious question.

So I know limestone is technically a non-renewable resource, since we're using it far faster than it is being created.

Should, uh, we actually be worried? It's like 7% of the Earth's crust; are we actually using limestone fast enough to use up a significant fraction of the usable limestone in the expected lifetime of humanity?

Not in the least. There are other resources that we do need to worry about, of course. But lime and limestone are not on the list.

I've always wondered the same about iron ore, granite, marble etc.

The BBC put together a world resource list a couple years back that I think you might find interesting.

http://www.bbc.com/future/story/20120618-global-resources-st...

It lists a variety of elements (like antimony) that are surprisingly constrained. If I were to pick the most critical material on the list, though, it would be phosphates. The green boom that feeds the world needs phosphates, the world supply of phosphate-bearing rock is small, and there are no possible substitutes.

This. They are not making paper out of stone, they are mixing limestone in plastic. No doubt there are some benefits to it (less plastic is used - though not 80% less because limestone has higher density), but marketing this as "paper" is highly misleading.

Plastics are commonly whitened with Titanium Dioxide and Zinc Oxide already. Calcium Carbonate is a pretty benign chemical as far as potential problems for the plastic waste stream go. I don't see any outstanding issue with its recyclability.

I did not say that polyolefins were dangerous. But they are less biodegradable and less renewable than the trees of which paper is normally made. And while polyolefins like empty distilled water jugs are easily recycled, I very much doubt that this blend of limestone and polyolefin can be recycled by the usual curbside collectors.

>But they are less biodegradable and less renewable than the trees of which paper is normally made.

This is not the safe bet many people think. If you look at the entire lifecycle of a product, plastic bags (to take an example) have a better footprint across the board than paper ones.

http://www.alternet.org/environment/whats-better-environment...

> If you look at the entire lifecycle of a product, plastic bags (to take an example) have a better footprint across the board than paper ones. //

Importantly we don't factor in destruction of the planet: use of non-renewable oil and pollution (and is impact on food supplies, etc.). This is where the cost seems higher with disposable plastic, a cost we are yet to pay.

The footprint calculation is our best effort to factor everything in, and that includes environmental degradation.

I don't want to minimize the difficulty of this- it's really, really hard to get right. But we do learn things, and (perhaps most importantly) we learn counter-intuitive things. And one of them is that plastics, even taking the tremendous problems with garbage patches in the ocean and the like, and not the clear-cut negative that our emotional side tends to think.

I guess the birds getting killed by plastic bags in the environment and the sea are happy to know that the life cycle energy consumption is better than paper.

That said I do not use paper bags or plastic bags but a recycled canvas bag I've used for hundreds of shopping trips.

Good to hear it. You're probably close to breaking even on the environmental cost it took to make that canvas bag.

//

The more energy it takes to make something, the greater the potential environmental impact.

Plastic in the ocean is awful. The vast majority of it comes from just a few countries. What some westerner uses to take home their groceries isn't even a rounding error in terms of source waste.

https://www.fastcompany.com/3051847/most-of-the-plastic-in-t...

I probably am, 2x a week, 104x a year, Yx years.

"even a rounding error in terms of source waste."

Reading the report says "Low-residual-value plastic waste is more likely to leak than high-value plastic [...] his means that products or packaging with low residual value (plastic shopping bags, for instance) are less likely to be collected; they therefore become a particularly significant contributor to ocean plastic"

Yes, that is correct.

Please also note that the biggest contributor, and the biggest reason for China being that contributor, is simple lack of a functional garbage collection system at all in large parts of the country.

I emphasize this because I think people tend to focus on the minutiae (ie, paper, plastic or canvas when it comes to grocery bags) when the bulk of the problem has nothing to do with bag choice, it has to due to a complete lack of wastestream infrastructure. It is understandable to a degree. The problem is so overwhelming, it feels like what one person can do is never going to be enough.

40% of plastic waste is not from the 5 countries. You make it sound as if China is only responsible for the oceanic plastic waste.

China is the primary contributor. It certainly isn't the only one! Plastic control is a worldwide problem.

Do you know how heavy duty reusable plastic bags made from recycled plastic fare?

I have some that have lasted for years now.

The only information I have regarding durable, intended-for-reuse grocery bags is for canvas, and the carbon break-even point is somewhere ~150 uses compared to getting one-off bags every time.

I would guess that heavy-duty plastic would fare significantly better, because cotton in general is an awful crop from an energy input standpoint, but I can't give you a more precise answer than that, I'm afraid.

If canvas bags are better after 150 uses, and in general are seen as wasteful to produce, I think that recycled plastic bags are fine. Thanks for the info.