Human: I've been hearing a lot about fracking lately. What is it, and what are the potential environmental consequences? Assistant: 
Fracking is the process of extracting natural gas from shale rock formations using high-pressure water injection. It has become increasingly popular in recent years due to its relatively low cost and the large amount of natural gas that can be extracted from these formations. However, there are concerns that this process could lead to groundwater contamination, air pollution, and even earthquakes.