Final answer:
Energy efficiency is important in reducing CO2 emissions as it cuts down on the amount of fuel needed, lowering greenhouse gas emissions and combating global warming. Higher energy efficiency leads to less CO2 emitted, reducing the enhanced greenhouse effect and helping stabilize the climate.
Step-by-step explanation:
Energy efficiency is crucial to reducing CO2 emissions because modern industrial society relies heavily on energy obtained from the combustion of fossil fuels -- processes that release significant amounts of carbon dioxide into the atmosphere, driving the greenhouse effect and global warming.
The greenhouse effect, responsible for maintaining Earth's habitable temperature, is exacerbated by the increasing CO2 concentrations, leading to a rise in global temperatures. Thus, enhancing energy efficiency serves as a key strategy to address the steep rise in CO2 levels caused by fossil fuel burning and deforestation, contributing to a reduced greenhouse effect and assisting in stabilizing the planet's climate.