In a system, something that limits an output is called "negative feedback."
An example is a house's thermostat. The family uses a furnace to heat their house. They decide what temperature to keep the house, and set the thermostat for that temperature. The thermostat is simply a temperature sensor that flips an on-off switch to maintain the assigned temperature.
The police have a function similar to a thermostat's. They arrest criminals, and introduce negative feedback to crime.
Regulatory agencies introduce negative feedback to pollution, and other costs which businesses might attempt to externalize, or pass on to parts of society which don't share in their profits.
Another example of negative feedback on pollution has been offshoring of American manufacturing. Move a factory to Hangzhou, and move its pollution.