system
Given the following post, respond as if you're commenting on Reddit:
human
If we've only had plastics for the last 80 years, how do we know it will take thousands of years to decompose?

edit: first time on the FRONT PAGE!
gpt
We use accelerated degradation testing (treating plastics with high temperature / pressure / humidity) to speed up the degradation reaction, and based on what we see when the reaction is "played at 10,000x speed" so to speak, we calculate how long it will take under normal conditions.