We hear a great deal today about the carbon footprint we, our homes, and our businesses generate. For many people, the term sounds a little abstract and removed from daily life, but it’s actually completely down-to-earth. Your carbon footprint is the total measure of the greenhouse gases (carbon dioxide and other harmful gases released into the atmosphere) generated by your lifestyle choices.

A carbon footprint measures not only the number of greenhouse gases emitted through your daily activities, but also through the production, development, and transportation of the goods and services you use.

The idea of measuring carbon emissions in this way first came about in the 1990s, when two the University of British Columbia scientists identified the “ecological footprint” as the combined land area needed to sustain a population or its activities. Unlike the calculation for an ecological footprint, which measures the environmental impacts of land and water use, scientists measure carbon footprints in tons of carbon dioxide (or its equivalent) produced annually.

Our carbon footprints vary depending on where we live and work but are also based on how careful we are about minimizing the damage we do to the environment.

Five pieces to the puzzle

Experts typically focus on five areas of life when calculating your carbon footprint: housing (which includes fuel, electricity, water, and waste disposal), travel (including the use of private vehicles, public transit, and flying), food consumption (which also includes growing, processing, packaging, and delivery to markets), consumer products (meaning new goods of all kinds, including clothing, household items, toys, medical devices, and more), and services (taking in educational and recreational experiences, communications, vehicle maintenance, personal services, and more).

These calculations can be very granular. For example, in calculating energy use in your carbon footprint, you divide the amount of energy used in your home by the number of members in your household. Online carbon footprint calculators typically also ask for input about the type of energy used (electricity, natural gas, propane, etc.) and its amount in kilowatts or gallons. To factor in the carbon footprint of water use and waste disposal, you would likewise take the total amount used in a household and divide that figure by the number of household members.

Handy online tools

The Nature Conservancy and the World Wildlife Fund are just two of many nonprofit organizations that offer online carbon footprint calculators and questionnaires on their websites. The United Nations provides a similar calculator. All take into account your housing situation, energy use at home, regular travel, buying habits, what you eat, and other factors.

Other online calculators, such as the one the BBC published in an article in August 2019, as a “climate change food calculator,” provide the carbon footprint generated by a number of specific common foods. This calculator is based on UN Intergovernmental Panel on Climate Change research showing that high rates of consumption of meat and dairy products contribute heavily to climate change.

The urgent need for change

Globally, the average individual carbon footprint is around 4 tons per year. But for residents of the United States, it averages 16 tons per year. Americans have one of the largest average carbon footprints on the earth. Climate scientists have calculated that, in order for the world to avoid a dangerous 2° Celsius rise in global temperatures, the average individual carbon footprint must measure under 2 tons per year by 2050.

A major change like this one won’t happen quickly. But by making seemingly small but noticeable changes in daily life, we can achieve it.

A few simple practices can help

Experts offer the following simple but effective advice for reducing your carbon footprint:

• Choose renewable energy to power your home if you can.
• Limit airplane flights.
• Use public transit, walk, or bike instead of driving a car.
• Skip the dryer and let clothes dry on a good old-fashioned clothesline.
• Stop buying “fast fashion”—cheaply made, trendy garments designed to wear out quickly so you keep buying more.
• Leave devices unplugged whenever possible. Even if powered down, they can still draw energy when plugged in.
• Plant your own garden and eat what you grow.
• Cut down on the amount of red meat you consume.

Remember that even small changes can make a big difference. For example, you might take public transit to work or plan a meat-free dinner one day per week.

A number of experts believe that modern industrial farming practices are just as big a threat as fossil fuels, in terms of greenhouse gas emissions. Red meat production is a major culprit here, using up about 11 times as much water as poultry production and generating about five times the amount of greenhouse gases.

In addition, it’s estimated that one-third of all the food humans in developed countries produce ends up in the garbage can. Once that food starts decomposing in a waste dump, it releases methane—another greenhouse gas—into the atmosphere. In fact, food waste is responsible for about 8 percent of the global greenhouse gases emitted.

A few simple ways to reduce your food waste include planning meals in advance and buying no more than you need, ordering smaller portions in restaurants, and getting leftovers boxed to take home.