Final answer:
The primary contributor to carbon emissions impacting the human carbon footprint is d. energy production due to the burning of fossil fuels. Renewable energy sources are critical in reducing these emissions.
Step-by-step explanation:
The greatest source of carbon emissions impacting the human carbon footprint is energy production, which primarily involves the burning of fossil fuels like coal, natural gas, and oil. It is this combustion process that significantly contributes to the increased levels of CO₂ in the atmosphere. To illustrate, energy production for generating electricity made up 26.9 percent of U.S. emissions, while transportation systems, which include passenger cars and light-duty trucks, contributed 28.2 percent.
However, energy production has a more significant impact globally. Furthermore, advancements in renewable energy sources like solar and wind power have the potential to reduce these emissions, as seen in Morocco and The Gambia's commitments to green energy programs.