The bottle, like the rest of our trash, may slip easily from our hands and minds, but it doesn’t leave our collective refuse piles so quickly. Landfills, which are lined with clay and plastic, layered with soil, and capped, are not extremely hospitable when it comes to microbial degradation. The three necessary components for decomposition—sunlight, moisture, oxygen—are hard to come by in a landfill; items are more likely to mummify than to break down.