Question

what energy changes have occurred in the environment as a result of human activity?
how might humans and the rest of the environment be affected if we do nothing?
how might humans and the rest of the environment be affected if we carry out the solutions we have discussed?

Explanation:

The questions are about the impact of human activities on the environment and energy changes, which falls under Environmental Sciences (a subfield of Natural Science). The questions explore energy changes due to human activity, and environmental impacts of inaction or action, all relevant to studying the environment and human interactions.

Answer:

Environmental Sciences (Natural Science subfield)