No, a paper bag is not “sustainable.” Here is the math to prove it

Not many people spend their idle hours reading research findings about trash management. I do. What happens to a material at the end of its life is at the core of the work I do.

So imagine the shock I felt when I learned that a newspaper could be buried in a landfill and still be perfectly legible more than 40 years later.

We know this is true because of William Rathje, an archaeologist at the University of Arizona who spent decades doing something nobody else wanted to do. He dug up garbage. His Tucson Garbage Project excavated 10+ American landfills between 1987 and the 2000s, pulling out layer after layer of buried waste. His team recovered 2,425 newspapers, some from the 1950s, still readable. And paper was not some minor finding. It was the single largest category of waste by volume in every landfill they opened.

That fact stayed with me.

So when India banned identified single-use plastic items in July 2022 and tightened carrier bag thickness rules to 120 microns by December that year, paper bags flooded every retail counter and e-commerce shipment in the country. I assumed, like most people, that this was progress. Paper is natural. Paper is biodegradable. Paper is sustainable. Right?

Then something very odd hit me.

I looked at the numbers. The global packaging industry is valued at over $1.2 trillion. The paper packaging segment alone is worth over $370 billion. Bioplastics packaging, the industry I work in, accounts for roughly 1% of total packaging materials worldwide.

Paper has had a decade-long head start as the “sustainable” alternative, and yet the global packaging waste problem is far from solved. The oceans are full of it. Landfills are overflowing. Your grandchildren will inherit dirtier water, dirtier air and dirtier soil because of decisions being made right now.

So I got curious. If paper packaging has been positioned as the responsible choice for this long, why has it not moved the needle? Is paper sustainable in the way we have been told, or is something else going on entirely?

What I found was unsettling. And I think every entrepreneur making packaging decisions deserves to see the same data I did.

From forest to checkout counter: The environmental price of one paper bag

When we ask if paper is sustainable, we need to look at the full production chain, not just the finished product sitting on a shelf.

A paper bag passes through multiple stages before it reaches your hands: forestry, pulping, chemical processing, bleaching, drying and converting. Each stage carries an environmental cost. Let me walk through the big costs.

1. Start with energy. Manufacturing a single paper bag requires roughly four times the energy of manufacturing a comparable plastic bag.
2. Then water. For context, United States pulp and paper mills use an average of 17,000 gallons of water per ton of paper produced. India’s Central Pollution Control Board (CPCB) reports that wood-based Indian mills consume 40 to 60 kiloliters of freshwater per tonne. By one widely cited industry comparison, paper bags use approximately 17 times more water per bag than plastic bags.
3. Then chemicals. The kraft pulping process, which produces most of the world’s paper bags, digests wood using sodium hydroxide and sodium sulfide. Even modern bleaching methods that avoid elemental chlorine still discharge dioxins and adsorbable organic halides into waterways. A peer-reviewed study of Indian paper mills found effluent with chemical oxygen demand levels of up to 19,100 milligrams per liter, well above permissible limits.

Of course, every manufacturing process has environmental costs. That is not the problem in itself. The real question is whether those upfront costs are offset by what happens next.

Paper is marketed as reusable and biodegradable. Those claims are supposed to justify the heavier production footprint. But the numbers I found next made that trade-off very hard to defend.

The 43-reuse problem: What lifecycle research says about paper versus plastic

Two government-commissioned lifecycle assessments (LCAs), considered the gold standard in environmental accounting, have quantified exactly how paper bags compare to plastic bags across their entire existence.

1. The United Kingdom Environment Agency’s 2011 study tested supermarket carrier bags across 10 environmental impact categories. The result: a conventional high-density polyethylene (HDPE) plastic bag was found to have the lowest environmental impact in nine of those 10 categories. For a paper bag to match a plastic bag on climate impact alone, it had to be reused at least three times.

Three times sounds manageable. But then came the Danish Environmental Protection Agency (EPA) study in 2018.

1. Conducted by researchers at the Technical University of Denmark and published as Environmental Project No. 1985, this LCA measured bags across 16 indicators, including acidification, water use, ozone depletion and ecotoxicity. Their finding: An unbleached paper bag must be reused 43 times to match a low-density polyethylene (LDPE) plastic bag across all environmental indicators.

Forty-three times.

Now ask yourself honestly. How many times have you reused a paper bag? They lose structural integrity when wet. They tear under moderate weight. Most are used once and go straight to the bin.

That is the gap between the story we tell ourselves and what the data actually says about whether paper is sustainable.

And this is not an isolated result.

A 2024 study published in Environmental Science and Technology by researchers at the University of Sheffield, Cambridge and KTH Royal Institute of Technology examined 16 plastic product applications covering roughly 90% of global plastic volume.

In 15 of 16 applications, plastic had lower lifecycle greenhouse gas (GHG) emissions than its alternatives, including paper.

So if the production footprint is heavier and the reuse math does not add up, what about the end-of-life story? Is this where paper is supposed to redeem itself? It does not.

Your paper bag is not composting — it’s generating a greenhouse gas far worse than CO2

Most people assume paper bags decompose quickly after disposal. Rathje’s landfill excavations proved otherwise. But the reason is not some quirk of paper chemistry. It is how modern landfills actually work.

Sanitary landfills are engineered to be anaerobic. They are sealed, compacted and kept dry. When there is no oxygen, paper does not compost. It just sits. And when it does eventually break down in those oxygen-starved conditions, it does not simply disappear. It generates methane, a GHG with roughly 28 times the warming potential of carbon dioxide (CO2) over a 100-year period.

The scale of this matters. According to the U.S. Environmental Protection Agency, municipal solid waste (MSW) landfills were the third-largest source of human-related methane emissions in the U.S., responsible for 14.4% of the country’s total methane output in 2022. That equals the emissions from 24 million passenger vehicles driven for a full year.

A plastic bag sitting inert in a landfill is not good. But a paper bag actively generating methane in that same landfill is even worse.

What paper gets right, and why it still falls short as a solution

I want to be fair here because the data is not all one-sided.

1. Paper does biodegrade in open, aerobic environments where plastic would persist for centuries.
2. In coastal regions with high waste leakage into oceans, paper causes far less marine damage.
3. India’s paper industry sources roughly 70% to 75% of its raw material from recycled fiber, which dramatically reduces the virgin wood and water footprint.

So the point is not that paper is bad. The point is that swapping one single-use material for another single-use material is not a solution. It is a sideways movement, dressed up as progress.

The question is not paper or plastic. It is why we still design for single use

The United Nations Environment Programme’s (UNEP) own meta-analysis of lifecycle assessments reached a conclusion that belongs on the wall of every packaging startup: reuse, not material substitution, is the only consistently effective intervention.

The question is not paper or plastic; it’s “why are we still designing for single use at all?”

For entrepreneurs building products, supply chains or packaging systems, this reframe changes the game. The opportunity is not in finding a slightly less harmful disposable. It is in designing materials and systems where disposability itself becomes unnecessary:

• Materials derived from agricultural waste that meet real composting standards
• Closed-loop packaging that comes back after use
• Products engineered for dozens of cycles, not one

The market is ready. Consumers want sustainability. But they deserve solutions backed by lifecycle evidence, not by marketing copy printed on a brown paper bag.

So the next time someone hands you a paper bag and says “at least it is not plastic,” I would encourage you to ask a harder question. Not “what is it made of?” but “how many times will it be used?”

That is the question that separates sustainability theatre from actual progress. And for entrepreneurs, it is where the opportunity begins.

Not many people spend their idle hours reading research findings about trash management. I do. What happens to a material at the end of its life is at the core of the work I do.

So imagine the shock I felt when I learned that a newspaper could be buried in a landfill and still be perfectly legible more than 40 years later.

We know this is true because of William Rathje, an archaeologist at the University of Arizona who spent decades doing something nobody else wanted to do. He dug up garbage. His Tucson Garbage Project excavated 10+ American landfills between 1987 and the 2000s, pulling out layer after layer of buried waste. His team recovered 2,425 newspapers, some from the 1950s, still readable. And paper was not some minor finding. It was the single largest category of waste by volume in every landfill they opened.