Explain the process behind the scientific method and how it has the potential to lead to a "feedback loop"

The process of the scientific method involves making conjectures (hypotheses), deriving predictions from them as logical consequences, and then carrying out experiments or empirical observations based on those predictions. ... Scientists then test hypotheses by conducting experiments or studies.

the answer is:

carbon dioxide

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.