PittMoss

PittMoss makes growing media out of recycled paper and cardboard, replacing the peat moss that most potted plants on earth are grown in. Peatlands store about a third of all soil carbon, and harvesting them releases it, along with nitrous oxide, while destroying habitat that took thousands of years to form. The UK has banned peat for horticulture. Most of what North America uses is shipped in from abroad.

The substitute has to grow better plants, or growers won't touch it, and PittMoss's does: more vigor on less water and less fertilizer, made regionally from a waste stream that is abundant everywhere people live. Peat is one of those materials nobody chose so much as inherited. It is dug out of one of the densest carbon stores on the planet so that a plant can sit in it for a season.