Question

what factor has the biggest impact on climate?

Explanation:

Among many factors, the sun is a major influence as it provides the energy that drives Earth's climate system. However, in the context of recent human - influenced changes, greenhouse gas emissions, especially carbon dioxide from burning fossil fuels, have a huge impact by trapping heat in the atmosphere.

Answer:

The sun is a fundamental natural factor, but human - caused greenhouse gas emissions are having a large and growing impact in modern times.