Two popular methods of measuring your home’s ecological impact are the Ecological Footprint (EF) and the Household Carbon Footprint (HCF).
Ecological Footprint (EF) – The EF has emerged as a leading measure of humanity’s (and your personal) demand on nature. It measures how much land and water area a human population requires to produce the resources it consumes and to absorb its wastes, using prevailing technology. Your EF is broken into Consumption Categories and Biomes.
• Consumption Categories – Consumption Categories show where you consume resources and generate waste. The categories include Carbon Footprint, Food Footprint, Housing Footprint and Goods & Services Footprint. This is usually represented in a percentage breakdown, all categories together adding up to 100%.
• Biomes – Biomes describe how many ‘global acres’ are required to support your lifestyle. Biomes include energy land, crop land, grazing land, forest land, built-up land and fishing grounds.
There are many EF assessment tools available online that can help you determine the EF of your home.
Household Carbon Footprint (HCF) – Your HCF describes the total volume of greenhouse gas emissions caused by the activities of your home over a period of time. The concept of a carbon footprint is important because it creates a relationship between your actions and the amount of greenhouse gasses emitted because of them.
Common greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide and ozone. For simplicity, the total volume is measured in carbon dioxide equivalents (CO2e), which combine all the greenhouse gasses together. CO2e is a quantity that describes, for a given mixture and amount of greenhouse gas, the amount of CO2 that would have the same global warming potential (GWP), when measured over a specified timescale (generally 100 years).
Greenhouse gasses, which are primarily created from burning fossil fuels and by raising livestock, are released into the atmosphere where they absorb solar radiation. This radiation takes the form of trapped heat that would otherwise escape back into space. This process is the fundamental cause of what scientist refer to as the Greenhouse Effect. The term Greenhouse Effect is used because, much like a greenhouse, when solar radiation is trapped, it will cause a rise in temperatures.
Global annual temperatures have been rising since the beginning of the industrial revolution, when factories (and later automobiles) began emitting high volumes of CO2. The rise in global temperatures has increased exponentially over the past several decades. It is predicted that if left unchecked, this rise in global temperatures will have catastrophic economic and ecological effects in the coming century.
✔ Calculate your Household Carbon Footprint – There are many online resources available that can help you calculate your HCF. They will generally be in the form of an online survey. The survey will require you to submit information about your home (size, location, number of windows, etc.), appliances, driving and flying habits and other carbon factors.
✔ Take direct steps to reduce your HCF – Once your HCF is known, you will be able to take steps to track and reduce it. Increasing the energy-efficiency of your home and living a ‘greener lifestyle’ are excellent places to begin. Steps such as driving less, reducing your home energy consumption, buying locally grown food, and buying ‘green energy’ from your utility company are some examples.
✔ Consider buying carbon offsets – Despite the direct steps you take to reduce your HCF, some volume of CO2e will remain. In order to bring your HCF to zero (carbon neutral), consider buying carbon offsets. Carbon offsets reduce your carbon impact by ensuring that somewhere else on the planet, an equivalent amount of carbon dioxide is reduced as a result of your offset purchase. Except for reforestation projects, which can sequester emissions currently in the atmosphere, carbon dioxide isn’t removed from the atmosphere; rather emissions of new carbon dioxide are prevented. In either case, the environmental benefit is the same.
Because carbon offsets are fairly intangible, you need to take precautions to ensure that your purchase is having the intended impact. Try to make sure that the offsets follow one of the major industry standards. A variety of standards such as the U.N. Clean Development Mechanism, Chicago Climate Exchange, Environmental Resources Trust, California Climate Action Registry, Voluntary Carbon Standard, Green-e Climate and Gold Standard provide assurance that projects follow rigorous quality metrics. Environmental Defense and the U.S. EPA Climate Leaders program also have standards they endorse for high-quality offsets.
This is an excerpt from the book “Greening your Home” by Anthony Gilbreath.