Sewers have been hiding a climate problem in plain sight, and this new tool finally exposes its true scale. The team estimates that sewers worldwide emit 1.18 to 1.95 million tons of methane annually.

From searching: “Global methane emissions reached approximately 610 million tonnes (Mt) annually as of 2024, according to the [IEA – International Energy Agency](https://www.iea.org/reports/global-methane-tracker-2025/key-findings).”

So sewers contribute 1.2 to 1.9 mt of 610 — lets see, that’s 0.3%

From the linked article:

>The team estimates that [sewers worldwide](https://phys.org/news/2026-02-methane-countries-underestimating-wastewater-greenhouse.html?utm_source=embeddings&utm_medium=related&utm_campaign=internal) emit 1.18 to 1.95 million tons of methane annually. This reveals that global wastewater management has a far more significant impact on greenhouse gas emissions and global warming and is crucial for improving greenhouse gas emissions accounting and promoting global emissions reduction.

No, global wastewater management is not crucial for improving GHG at 0.3%. If through some miracle the world united behind addressing sewer methane and pumped billions of dollars into upgrading infrastructure, and over the course of years managed to reduce this number by 50% — we would be saving 0.15% of global annual methane emissions, which is not material.

That time, energy, and money could get much better GHG reduction returns elsewhere.

So —- good job, study team, this is interesting, but not really meaningful. Now, why don’t you turn your attention to methan emissions from energy production, live stock, or the things we know are significant contributors. Oh – I know: Because studies are easier to do than it is to muster the political will to actually address the results of the studies.

There are known solutions for this. A couple of decades back, Straus Dairy bought a bioreactor to turn their barn washings into electricity.