How Many Earths Would it Take to Sustain Humanity?
Let’s talk about “Earth Overshoot Day”. It is a very important day but not one to celebrate, unless it happens on December 31 (or not at all). It is the day on which we have used up all of the resources that the Earth can replenish in one year. So every day after Earth Overshoot Day we are borrowing resources against our futures, accumulating ecological debt that we cannot repay.
The first Earth Overshoot Day was December 29, 1970. Prior to that we were living within our ecological means. That’s not to say we were not doing any harm to the planet, only that we were using nature’s resources at a rate slow enough that the Earth could replenish them. Since 1970, Earth Overshoot Day has moved steadily earlier, reaching July 29 in 2018 and 2019. And then we found ourselves in a global pandemic and we saw the best Earth Overshoot Day we have seen since 2005.
In 2020, Earth Overshoot Day fell on August 22. That’s 3.5 weeks later than in the two previous years. One of the positives to come out of a difficult and unpredictable year has been that we have had to change our habits and adapt. For many of us it has served as a reminder of just how adaptable we are as a species – and the Earth has breathed a little easier as a result. Air quality has been higher, water pollution has been lower, and sensitive ecosystems have been restored (1).
Now that we have had this accidental demonstration of the positive environmental impact we can have through collective action, we propose that we keep the momentum going by examining our personal Overshoot Days a little more closely – and then making lifestyle changes to improve them!
Our personal Overshoot Day is the day on which we would have used up all of the resources that the Earth can replenish in one year if everyone on the planet lived like us. We can also calculate Earth Overshoot Day for countries – Canada’s is currently March 14, meaning that if everyone in the world lived like an average Canadian we would use up the Earth’s natural resources for the year in less than 3 months! Global Footprint Network has prepared an online quiz to help estimate your personal Overshoot Day based on your lifestyle and habits. Head on over to take the quiz, or read on to learn more about the justification behind the questions.
Take the first step with the Global Footprint Network’s calculator
Animal-based products: The food we eat is a major contributor to our carbon footprints. Food production from farm (or factory) to table takes a lot of water, energy, and resources and is a big emitter of greenhouse gases. There are ecological impacts from fertilizers and pesticides, irrigation, clearcutting of forests to make space for livestock grazing or agriculture, transportation of food, transportation of fertilizers and pesticides, production and disposal of packaging, and disposal of food scraps and waste. On average, consumption of animal products has a higher carbon footprint than consumption of plant-based products. There are two main reasons for this:
1) When we consume animal products, our ecological footprint includes all of the water, energy, resources, and land that went into producing THAT animal’s food. The food and water consumed by livestock is not all converted directly into the animal products that we eat. The animals use much of the energy from their food for their own metabolism, to allow them to do things like walking, breathing, digesting, and producing body heat. It is therefore much more energy- and resource-efficient to eat plant-based foods directly rather than growing food to feed to livestock, or clearcutting forests to allow them to graze.
2) Ruminant animals such as cattle (cows) and sheep produce high levels of methane through their burps and flatulence due to their unique digestion. Methane is shorter lived than carbon dioxide but about 30 times more potent as a greenhouse gas! Beef and lamb are therefore two of the highest emitters of GHGs out of all of the foods we eat.
Reducing or eliminating consumption of animal products can have a big impact on our carbon footprints. For the biggest impact, reduce consumption of beef and lamb.
Food packaging, processing, and transportation: Part of our food-related carbon footprint comes from the packaging, processing, and transportation of the food. Packaging takes energy and resources (often fossil fuels to create single-use plastics) to make, and takes more energy and resources to recycle or goes straight to landfill. Processing of foods takes energy, plus the resources to build and maintain factories. Transportation of food uses fossil fuels which emit greenhouse gases and harm air quality. We can reduce our carbon footprints by choosing unprocessed, unpackaged, locally grown foods more often.
When unpackaged foods are not available, we can reduce packaging by buying the biggest sized package that we will use within the product’s shelf life. Buying the big package to reduce packaging but then throwing most of it away defeats the purpose. Living in Canada we do not have access to a large variety of fresh, local produce year-round. In the winter months, we can try consuming some of our fruits and veggies as preserves made from local produce while it’s in season, whether we purchase from local farms or artisans or try making them ourselves. Want to reduce your carbon footprint without giving up all that delicious fresh produce? Start by switching to locally-grown for highly perishable foods! Choosing foods that have long shelf lives and came from afar means that they likely traveled by ship, rail, or road, as opposed to foods with short shelf lives which must travel by plane to try to beat the clock and get to us before they rot. Air transport has a much higher carbon footprint than sea transport, emitting approximately 100x as much GHG (2). Some of the foods most likely to come to us by air are asparagus, green beans, and berries.
Housing: Where we live is another big contributor to our carbon footprints. If we live in a home with electricity and running water, we are responsible for the footprint associated with our share of the infrastructure required to support these amenities. If we live in a cool climate, it is more efficient to heat homes that share walls or ceilings, such as row houses or apartment buildings. Building materials such as wood, brick, and steel take more energy and resources to produce than straw or bamboo. If multiple people live in our home, the footprint associated with the home’s heating and infrastructure is divided among them. A home that is well-insulated and uses passive methods of heating and/or cooling (such as opening and closing blinds or windows at strategic times) is heated/cooled more efficiently. If our homes are powered by renewable energy sources then our carbon footprints are lowered.
In Canada and other countries with colder climates for at least part of the year, heating our homes is one of the biggest contributors to our GHG emissions, so the method by which we heat our homes can make a big difference to our footprint. (In case you are wondering when you get to these questions, Ontario currently gets 33.4% of its electricity from renewable sources).
Waste: When asked about waste, be sure to click the option to add more details to improve accuracy. This question takes into account way more than just the garbage you take down to the curb! Our garbage footprints include the obvious items such as food packaging, but they also include much more. Almost every item that we buy is destined for the landfill someday. We may sell or donate our old stuff, or tuck it away in a basement or attic in case we want it again someday, but that only delays its arrival at the dump. So, our garbage footprints include our clothing, furniture, sporting goods, electronics, toys, and more. Even recyclable items often 1) end up in a landfill due to contamination or lack of demand for the recycled product or 2) get “downcycled” into an item which will then end up in a landfill. Electronics in particular have a high footprint resulting from the mining of the rare metals that allow our devices to function. One of the best and easiest ways to reduce the impact of our waste on our carbon footprints is to consume less:
- Make your clothes last longer by buying quality if your budget allows, avoiding impulse purchases, and resisting the urge to keep up with every new trend. Avoiding “fast fashion” stores is a great place to start. If you’ve never heard the term “fast fashion”, think cheap, disposable clothing. For more on fast fashion check out the documentary “The True Cost”).
- When you start thinking of updating your furniture or decor, try making your existing furnishings last another month (or 6, or 12…)
- Don’t buy into “perceived obsolescence”, a marketing ploy aimed at making us feel like we need to have the latest technology as soon as it’s available. Instead, try using your devices (such as phones and tablets) for as long as they work well.
- Say no to freebies. Do you really need another branded, oversized T-shirt? Another pen? A business card holder for your cellphone?
When we can’t (or don’t want to) consume less, we can still reduce the carbon footprint associated with our stuff by buying secondhand whenever possible. Thrift stores and consignment stores are a great option, and can be a budget-friendly way to find gently-used, quality items. There are also many online buy-sell groups that may be worth checking out. A common misconception is that buying secondhand (or selling/donating your stuff) saves that item from the landfill. It doesn’t – that item is still headed to the dump. What it does is prevent the manufacture of another item, saving that item from the landfill by preventing its existence. This means that buying secondhand only has a positive impact on your carbon footprint if you are buying something secondhand that you would have otherwise purchased brand new.
Transportation: Transportation is another major contributor to our carbon footprints. Travelling by car emits GHGs. Travelling by public transportation does as well, but on a well-used system it works out to much less per person. Walking or biking are great ways to lower your carbon footprint if your ability and situation allow! Bonus: they can also contribute to a healthy lifestyle.
Air travel has a huge carbon footprint, especially at night and in the winter (yes really – go ahead, Google it!) Reducing the amount of time we spend flying has a big, positive impact on our carbon footprints. Sometimes air travel is difficult to avoid, such as to visit family living far away or when it’s required for work. And sometimes we don’t want to avoid it because we want to see more of the world or get away for a while. If any of these apply to you, you can still reduce your carbon footprint by:
- Taking flights during the day and avoiding winter air travel if possible
- Going longer between trips if possible
- Speaking to your professional contacts about meeting virtually rather than in person
- Choosing the closer destination when debating between potential travel destinations
Here’s that link again to take the test and find out your personal Overshoot Day. We would love to hear from you about your results, and whether you decide to make any changes to your habits to reduce your carbon footprint. Did you try any of our suggestions? Tell us about it! Did you try something else? Tell us about that too! When we all start making these kinds of changes it will help us Move the Date. Let’s do our part to get Earth Overshoot Day to December 31. And then have a big, carbon-neutral celebration.
- Rumea, T. and Didar-Ul Islamb, S.M. 2020. Environmental effects of COVID-19 pandemic and potential strategies of sustainability. Heliyon, 6(9): e04965.
- Poore, J. and Nemecek, T. 2018. Reducing food’s environmental impacts through producers and consumers. Science, 360(6392): pp. 987-992.