Question

what role does water play in the earths energy system?
it only affects the earths surface temperature
it stores and transfers energy due to its high heat capacity and phase changes
it only acts as a medium for chemical reactions
it has no significant role in energy transfer

Explanation:

Water has a high heat - capacity, which allows it to store a large amount of heat energy. Also, during phase changes (e.g., evaporation/condensation), it transfers significant amounts of energy in the Earth's energy system. It does more than just affect surface temperature or act as a medium for chemical reactions, and it has a very significant role in energy transfer.

Answer:

It stores and transfers energy due to its high heat capacity and phase changes