How does a heating system pollute what percentage of pollution comes from heating hot water systems?

Heating systems can contribute to air pollution primarily through the burning of fossil fuels, which releases carbon dioxide (CO2) and other harmful emissions. Approximately 10-15% of total greenhouse gas emissions in residential buildings come from heating water systems, depending on the energy source used. Using electric or renewable energy sources can significantly reduce this pollution. Transitioning to more efficient systems and technologies also helps mitigate their environmental impact.