Calculating one’s carbon footprint will likely bring surprises as to what contributes to one’s footprint the most. This may be true for most of us who are unaware of the impact that certain decisions and actions can have on the environment, even while actively trying to live a more sustainable lifestyle.
This article acts as a guideline for the most significant contributors to one’s carbon footprint and certain switches to limit the same.
Taking into account recent studies, we will have a look at three main dimensions: food, transportation, and home habits.
What Is A Carbon Footprint?
Simply put, a carbon footprint is the amount of greenhouse gases emitted through a person’s everyday life, both directly and indirectly.
Why Does It Matter?
As climate change worsens throughout the world, our carbon dioxide emissions are and will become of the utmost importance. While there are many sources of carbon dioxide emissions that are not directly due to a single person’s actions, some of the biggest carbon dioxide emitters have indirect ties to everyday decisions.
A great example of this is in the choices one makes when purchasing food. Agriculture can have massive greenhouse gas emissions but by no means has to. If everyone is buying food that has been grown to be beneficial rather than harmful to our climate, the harmful practices will decrease.
With decisions like these, one can affect how their choices are indirectly impacting our climate and their carbon footprint.
Studies show that conscious choices can reduce an individual’s carbon footprint by 5-20% (4). Being mindful of your decisions is the first step to making a change!
How Is A Carbon Footprint Calculated?
A simple google search for “carbon footprint calculator” will spout millions of websites, most of which calculate your carbon footprint based on the kind of car you drive, how frequently you travel, what types of food you eat, your energy usage at home, and any other activities which may produce carbon dioxide.
These websites will frequently use predetermined algorithms that spit out a tonnage of carbon dioxide emitted from various actions generally under three main categories: food, transportation, and home. Now, let’s delve into how these categories impact a carbon footprint and how we might limit each of their greenhouse gas contributions.
The food supply chain contributes roughly 37% of global carbon dioxide emissions (1), making it one of the most important factors to consider when discussing carbon footprints and carbon emissions more generally.
There are many different means by which food is grown and produced. While it may not seem this way, the method that one’s food is grown can have a significant impact on that person’s carbon footprint.
Food offers a unique chance for people to lower their carbon footprint because rather than being severe decisions that you may have little control over, such as how your house is powered, food choices are primarily personal.
The use of fertilizers, for example, can increase the amount of greenhouse gas emissions from growing food by a significant amount. The use of nitrogen fertilizers, more specifically, accounts for most of the greenhouse gas emissions from fertilizers.
These nitrogen fertilizers include urea, which composes the most significant percentage of greenhouse gas emissions, NPK fertilizers, or nitrogen phosphorus and potassium fertilizers, making up the following greatest percentage of greenhouse gas emissions (1).
As a result, purchasing food from farms that are using little or no synthetic fertilizers can be a significant step to reduce your carbon footprint from your food.
One of the most accessible switches to make involves the consumption of animal products. On average, animal products tend to have larger carbon footprints than plant products. Some of this certainly has to do with how animals are raised with industrial agriculture.
In industrial agriculture, animals are often raised in concentrated animal feeding operations (CAFO). These CAFOs are incredibly harmful to the environment and the animals living there, causing them to have more significant greenhouse gas emissions.
This study done in the United States states, “no matter how it is measured, on average red meat is more GHG-intensive than all other forms of food” (2).
Interestingly enough, the same study found that non-red meat protein sources, such as poultry, fish, eggs, and nuts, have a similar carbon footprint to fruit and vegetables (2).
This is primarily due to the fact that while non-red meat protein sources have higher carbon footprints solely from production, fruits and vegetables tend to have higher carbon footprints from transportation.
A Yale study found that a vegetarian diet, as opposed to a carnivorous diet, reduces a person’s carbon footprint by 30%, or roughly the same as eliminating all per capita food waste (3).
While eliminating food waste may not be possible, a combination of both limiting food waste and limiting meat consumption can pose a great way to reduce one’s carbon footprint.
Check out this article for some tips for living a vegan lifestyle.
As discussed above, fruits and vegetables tend to have relatively similar carbon footprints to non-red meat protein sources, mainly because their delivery and transportation are more carbon-intensive. This is an excellent example of where food miles come into play.
Food miles are essentially the number of miles one’s food has traveled to get to their plate. In today’s society, our food miles tend to be high, as we ship food worldwide.
In the United States, fruits, in particular, are often shipped from out of the country, generally from more tropical regions. If you take a look at your bananas, there is a good chance that they say they have come from somewhere like Chile – that is over 5000 miles!
As the study above explores, food miles can have drastic impacts on the carbon footprint of a given food. Without transportation, fruits and vegetables would be far more sustainable than they are in practice. One excellent way to limit your food miles is to purchase food locally.
Going to the farmers’ market or grocery stores that source food more locally is one way to do this.
At Puratium, we are convinced that this locally grown food tastes so much better because it is fresher because it hasn’t been sitting in a truck, airplane, or cargo ship for days as it traveled to get to our plate.
By eating locally like this, not only are you limiting the carbon footprint of your food, you are also supporting small businesses; not only is this beneficial to the environment, it also helps the economy and community directly (retain jobs, strengthen local culture, etc.).
Approximately one-third of food produced for consumption is wasted, and over 40% of that waste occurs by the consumer or retailer (3). As a result, this is an area in which any of us can have significant influence.
A study from Yale University found that ‘wasted beef has a more significant impact than any other food or food group regarding greenhouse gas emissions.’
For every kilogram of food thrown into the landfill, roughly 0.69 kg CO2 eq is produced.
Meat tends to make up a large percentage of wasted food, so not only do animal products have higher greenhouse gas emissions during their production, but they also tend to be wasted more and therefore have greater life cycle carbon footprints.
While there are many, very complicated factors that go into the life cycle emissions of a given vehicle, hybrid cars are always a step up from combustion vehicles or gasoline vehicles.
Hybrid vehicles use a mixture of an electric battery and gasoline to power the car. As a result, hybrids tend to get outstanding gas mileage, which allows them to have lower life cycle emissions than combustion vehicles.
Hybrid vehicles, however, are more fuel-efficient when they are being driven around cities rather than on highways. So, hybrids are incredibly sustainable when being driven in cities rather than rural areas.
They are also more fuel-efficient when driven in mild climates, as opposed to extreme climates. Consequently, hybrids have the lowest life cycle emissions when driven in cities with temperate climates (11), such as on the west coast of the United States.
Hybrid vehicles also eliminate the need for carbon-intensive batteries, which are necessary for both plug-in hybrid cars and fully electric cars.
The following graph, taken from a study at Carnegie Mellon University (11), demonstrates the relative life cycle emissions of combustion vehicles (CV), hybrid vehicles (HEV), plug-in hybrid vehicles (PHEV), and fully electric vehicles (BEV).
While electric vehicles are an incredible invention and are a good form of transportation in a decarbonized world, they are not without flaws.
Electric vehicles generally have to be plugged in to charge the battery which powers the car. Owners of these vehicles often plug their vehicles in at their homes. While the house may be powered by renewable energy, such as solar power, it is more likely powered by fossil fuels.
As a result, there are carbon emissions associated with driving the car that may not seem obvious and may often be overlooked.
The most sustainable way to drive an electric vehicle, or charge an electric car, is through renewable energy sources. These energy sources are not necessarily available to everyone currently, as power grids, tend to run on oil, gas, and coal, at least in the United States.
The batteries that power electric vehicles also have some issues of their own. The production of these batteries causes electric cars to have a more significant environmental impact than gasoline vehicles by 50%, with almost half of the increase coming directly from the production of batteries (5).
These batteries also tend to be what makes electric vehicles more expensive and thus less affordable and accessible.
This environmental impact does not, however, only translates into greenhouse gas emissions. While the graph above shows that greenhouse gas emissions can be lower for some electric vehicles than combustion vehicles, electric vehicles’ production poses other environmental harms.
Biodiesel is fuel that has been made from biomass into liquid fuel (12). This biomass may come from ‘vegetable oils, animal fats, or used restaurant grease’ (13).
Biodiesel has the potential to be highly sustainable since it can be made from recycled materials such as restaurant grease, meaning it eliminates waste from one sector and turns it into a substitution for fossil fuels.
Because it can also be made from vegetable oils or animal fats, it has the potential to be slightly less sustainable, as these resources must be produced (sometimes unsustainably), although still better than diesel made from fossil fuels.
A study from the University of Central Florida found that the lifetime greenhouse gas emissions from a regular diesel truck are around 5,000 tons of CO2 eq.
In contrast, the lifetime greenhouse gas emissions from a biodiesel-powered truck are just above 4,100 tons of CO2 eq (14). While this is not a drastic difference in greenhouse gas emissions, it is undoubtedly an improvement.
The same study also found that, in general, electric and hybrid trucks are an improvement from biodiesel-powered trucks.
However, a significant benefit to biodiesel over a hybrid or electric truck is that it requires no modifications to be made to the vehicle before use.
You can simply change the fuel being used and have distinct reductions in greenhouse gas emissions, therefore lowering your carbon footprint.
Public transportation is a very effective means of limiting your carbon footprint. Part of this is because multiple people are transported with a fixed amount of emissions, making the emissions from each person relatively small.
Many buses are also electric or run by natural gas. While natural gas is still a fossil fuel, it generally burns cleaner than gasoline. While this cleaner-burning does not limit carbon emissions so much, it does restrict other toxins being emitted into the air.
Walking & Biking
Not only are walking and biking excellent ways to get exercise, but they also allow one to get around with virtually no carbon emissions as a byproduct.
While this certainly is not feasible for every situation, it’s a great way to limit your carbon footprint, even if you can only do it rarely. Every little bit makes a difference!
‘Aviation is one of the most energy-intense forms of consumption’ (15). Subsequently, they represent a massive potential to reduce one’s carbon footprint.
‘An economy-class return flight from London to New York emits an estimated 0.67 tonnes of CO2 per passenger’ (16). This is equal to roughly the same amount of carbon dioxide emitted by a person in Ghana for the entire year.
Limiting the number of flights you take, therefore, can have enormous reductions in your carbon footprint. While there are some situations that flying is genuinely the only reasonable option, in many other cases, there are many more sustainable options.
For instance, if you are traveling across the country, take the train or a bus. Both have significantly fewer emissions than driving and flying and may allow you to see the places you are traveling through from a different perspective!
This graph from the BBC (16) demonstrates the greenhouse gas emissions of various forms of travel per kilometer traveled and can therefore be very useful when deciding how you should travel.
Individual homes account for roughly 20% of global greenhouse gas emissions (6). It is an area that, if approved upon, can make drastic improvements to global carbon emissions.
Heating and Cooling
Approximately 20% of the carbon emissions from homes in the US come from heating, cooling, and general powering of the house (6).
This figure tends to be higher in more affluent households and lower in less affluent households, generally due to home size. Bigger homes take more energy to heat, cool, and power, and smaller homes require less.
Of these areas which use the most energy in homes, air conditioning makes up the most energy-intensive (6) of the three: heating, cooling, and general powering.
The greater energy efficiency of household appliances and heating/cooling systems are an effective way to mitigate carbon emissions, and thus carbon footprints, without simply eliminating the use of heating and cooling overall.
Along with this, keeping your thermostat at average temperatures, rather than really cold or hot, can also have a large impact on the energy use of one’s home. For the most energy efficiency, the heater should be set around 68-70 degrees Fahrenheit, and the air conditioner should be placed to about 78 degrees Fahrenheit.
To make heating and cooling more efficient, it is also best to use windows when possible, and ensure that vents are not covered, so that energy is not unnecessarily wasted.
While it may not be accessible for all people, another critical means of reducing your carbon footprint is through using renewable energy sources.
This may mean purchasing solar panels for your home to limit the amount of fossil fuels being used to power your home. Solar panels are also a great way to make electric cars have a smaller carbon footprint.
By charging an electric vehicle with solar power, the day-to-day powering of that vehicle relies solely on renewables rather than any form of fossil fuels.
Discussed above is an example of active solar. Also practical, while less direct and less discussed, is passive solar. Passive solar uses window placement and other features of the building to maximize heat gain in the winter and minimize heat gain in the summer to limit the amount of energy necessary for heating and cooling in a given building (8).
A study from the University of Michigan found a negative correlation between energy intensity and greenhouse gas emissions, and population density. So, one way to limit your carbon footprint from your home is to live in more densely populated areas, like cities.
Cities also limit the amount of driving one does, as the places one may usually drive to are within walking distance, and public transportation tends to be better and more efficient than driving.
Both small and large appliances are in increasing demand. As a result of this, energy use from appliances is increasing (7). Unfortunately, since appliances are powered by electricity generally, appliances in carbon-intensive countries tend to have huge carbon footprints (7).
Refrigerators tend to be the highest energy-consuming appliances in a given household.
One way to limit the amount of energy being used by the refrigerator is to ensure it is not left open, along with making the freezer as warm as possible (without allowing the food to defrost of course!) and making the refrigerator as warm as possible (again, while remaining at safe levels).
This increase in temperature will use less energy, as the temperatures inside of the refrigerator will be closer to those outside of it.
Another great way to reduce excess energy usage in your home is to unplug appliances when they are not actively used. Even when something is plugged in but is off, it still uses energy. This is called the phantom load.
Phantom loads can impact one’s energy usage, accounting for up to 10% of one’s energy bill (9), and therefore can be an effective means of lowering one’s energy usage, and thus carbon footprint.
Overall, suppose an appliance is not actively being used. In that case, it should either be turned off (for example, do not have the television simply playing in the background) or, even better, entirely unplugged.
Washing clothing is inherently energy-intensive as water may need to be heated, and drying clothes uses hot air.
A straightforward way to limit your energy usage during these processes is by 1, using cold water when washing your clothes, and 2, air-drying your clothes.
Not only does air drying reduce your carbon footprint through direct energy usage, but it also helps to lengthen the life of a given piece of clothing. By doing so, you will have to replace clothes less frequently, also reducing your carbon footprint and saving money!
The consumption of goods inherently produces environmental impacts directly (through their production) and indirectly (through their waste, etc.). As a result, the more one consumes, the greater their carbon footprint will be.
The more consumption, the more resources must be used in the physical creation of that product, and the manufacturing, transportation, and resource extraction.
Purchasing less, therefore consuming less, is a good practice both for the environment and to save money.
Through the Nagasaki University, a study in Japan found the following graph to represent the most effective lifestyle changes to reduce one’s carbon footprint (10).
From this graph, and much of what has been discussed throughout this article, one of the most significant ways to limit your carbon footprint is by simply consuming less.
Everything you buy has an inherent carbon footprint associated with it, and thus the fewer items you buy, the lower your carbon footprint.
For some insight into reducing consumption and waste, check out this article.
Things to Consider
While it is undoubtedly essential to be aware of your impact on our environment and climate systems, it is also imperative that we fight for structural change.
Although individual choices impact the Earth, due to the massive scale of climate change, bigger changes than just what type of car a person drives are necessary. Governments, large corporations, and even fashion brands are more likely to enact bigger changes than one single person’s decisions are.
Regardless, it is still essential to do everything that you can to reduce your impact while also fighting for your government and the companies you support to be fighting for a more negligible environmental impact in everything we, and they, do.
There are endless things one can do to limit their carbon footprints. This article merely scratches the surface with some of the most significant changes that can be made. Remember what could be called the triangle of actions: transportation, food, and home.
- It is best to limit one’s personal cars and flights, as both of these factors contribute majorly to one’s carbon footprint. If you must drive, do so in a hybrid or electric vehicle to limit your dependence and use of fossil fuels.
- Dietary choices can also have significant impacts on your carbon footprint. Eat less meat and eat locally to mitigate the carbon impacts of your diet.
- Finally, limit the energy use in your home. Do not leave electronics running unless necessary, use passive heating and cooling solutions (such as windows) as much as possible, and incorporate renewable energy sources into your home if you can!
Thus, calculate your carbon footprint to find out what your greatest contributors are to learn how to reduce your carbon footprint most effectively.
We also encourage you to take a look at our guide on climate change and the growing role of Solastalgia here.
Celeste loves being outdoors doing just about anything you can think of. If not, you’ll find her hitting the books 📗 relating to Ecology & evolutionary biology 🌿 or atmospheric and ocean science 🌊.