Answer: hydrosphere
Risks associated with gas hydrate mining were uncertain for a long time. But since it is done on the deep oceans, it is the hydrosphere is the earth’s subsystem that will be directly affected.
The hydrosphere is the liquid portion of the Earth which covers about 70% of the Earth’s surface, includes the oceans, seas, lakes, ponds, rivers, and streams and is a home for many plants and animals.