A combination of conservation efforts and a new high-efficiency heating system can often cut your pollution output and fuel bills by one-third, and in some homes by half. Just upgrading your furnace or boiler to a high-efficiency model can save 1–2 tons of CO2 emissions each year in colder climates.
More than three-quarters of all U.S. households have air conditioners. Energy consumption for home air conditioning accounts for more than 8% of all the electricity produced in the U.S. for all purposes, at a cost to homeowners of over $15 billion. That amount of electricity results in the release of roughly 196 million metric tons of carbon dioxide (CO2) per year, or an average for homes with air conditioning of close to 2 tons per year. A switch to high-efficiency air conditioners and implementation of measures to reduce cooling loads in homes can reduce this energy use by 20–50%.