Rank the sources of carbon dioxide emissions from greatest to least.

The correct answer highlights that fuels are the largest source of carbon dioxide emissions, followed by iron and steel production, cement production, and finally municipal solid waste combustion.

Fuels, particularly fossil fuels like coal, oil, and natural gas, are the primary contributors to global carbon dioxide emissions due to combustion processes that release CO2 when used for energy. This significant contribution from fuels comes from their widespread use in industries, transportation, and electricity generation.

Following fuels, iron and steel production is a major industrial process that emits a large amount of carbon dioxide. The production methods, particularly the reduction of iron ore in blast furnaces, involve significant energy consumption and chemical reactions that lead to CO2 emissions.

Cement production stands as a notable source of CO2 emissions as well, primarily due to the calcination of limestone (calcium carbonate), which releases CO2 as a byproduct. The energy needed for heating the materials also contributes to emissions.

Municipal solid waste combustion, while it does produce emissions, tends to be lower in comparison to the industrial processes mentioned. The amount of CO2 emitted from burning waste is generally less significant than that from the combustion of fossil fuels or other industrial activities.

By ranking the sources as fuels, iron and steel production,