What are CO2 equivalents?
Updated: Nov 14, 2021
Here at Floop, we talk about the greenhouse gas emissions from recipes in carbon dioxide equivalents (CO₂eq). But what on Earth does "CO2 equivalent" actually mean?
On first thought, you might think CO₂ equivalents refer to the amount of CO₂ released into the atmosphere. But it goes deeper than that.
Carbon dioxide (CO₂) isn't the only greenhouse gas. Methane, nitrous oxide, and fluorinated gases are responsible for warming our atmosphere, too.
Each of these greenhouse gases has the ability to absorb heat. When they're released into the atmosphere, the gases absorb and trap heat from the sun which heats up the planet below.
But each gas absorbs heat in different ways and stays in the atmosphere for different lengths of time. This means they have different warming potential and have a disproportionate effect on our planet's atmosphere.
How to compare apples and oranges
Some clever people at the Intergovernmental Panel on Climate Change (IPCC) created Global Warming Potential (GWP) values. They help us understand the warming impact of different greenhouse gases compared to CO₂.
A CO₂ equivalent is a metric measure that converts the amount of gas (usually in tonnes or kilos) to an equivalent amount of CO₂ with the same global warming potential.
The CO₂ equivalent is calculated by multiplying the mass of greenhouse gases by their GWP.
We express CO2 equivalent as CO₂eq in Floop, but you may see it written as CO₂e or CO₂-eq² elsewhere.
Head hurt yet? Here's a table to explain.
CO₂ has a GWP value of 1. Methane on the other hand has a GWP value of 28.
This means that 1kg of methane has a warming effect that is equivalent to 28kg of CO₂, over a 100 year period.
This would be shown as a CO₂ equivalent of 28 CO₂eq.
To find out the true climate impact of our food, we need to consider all greenhouse gases.
We're seeing more and more claims for "carbon neutral" and "net-zero" products. It's fantastic to see so many organisations becoming aware of their environmental impact and taking steps to reduce it. But sometimes these claims don't consider the full climate impact due to other greenhouse gases.
When we calculate the climate impact of your food in the Floop app, we consider all greenhouse gases - not just CO₂.
The CO₂eq data of ingredients in Floop is calculated from lifecycle assessments, which consider the total greenhouse gas emissions during production, processing, packaging, and preservation stages of the food production chain.
Let's consider the different greenhouse gas emissions for a quarter-pounder beef patty.
To make a single patty, a whopping 1.1kg CO₂eq of greenhouse gases are released into the atmosphere. That's almost ten times the beef patty's own weight, in gas!
If you've ever been around a cow, you'll know they can, at times, be a little stinky. Their burps, farts, and poo produce methane (responsible for the pungent smell) and this greenhouse gas is an ongoing by-product throughout the lifetime of a cow.
Caring for a cow also means you need lots of crops for food, over several months or years. Most of the time, crops get help from fertiliser which replenishes nutrients in the soil.
But the not-so-great side effect is that fertiliser production releases nitrous oxide (N₂O), and we know from the table that one kilo of N₂O is equivalent to 265kg of CO₂.
Then we consider the processing and packaging of beef. Machines are used to mince, slice and mix beef into various different types of products. Lots of electricity is used to power these machines and plastic production, meaning CO₂ and other greenhouse gases are released during electricity generation.
Finally, we look a how beef is moved from farms to production plants to the shop. Immediately we think of greenhouse gases coming from the engines of trucks and planes. To keep beef cool and unspoiled, refrigerated units and chiller lorries are needed, which are even more energy - and CO₂ - intensive.
While not included in lifecycle assessments, we should also consider that refrigerated units can contain fluorinated gases, like HFC-23. These gases can be released into the atmosphere if the units are damaged or not disposed of properly at the end of their life.
Make it simple.
Yes... it's complex! And that's exactly why we've created Floop. With so many factors and variables and information sources, it feels overwhelming to know exactly how sustainable our food is.
We're here to arm you with that knowledge, in your pocket. By calculating the full CO₂eq impact of your recipes, from farm-to-shop, you can make better, more sustainable food choices that suit you and our planet.
You'll also be ready to question "carbon neutral" and "net-zero" claims to uncover foods that really fits your values.
Myhre, G., D. Shindell, F.-M. Bréon, W. Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. Zhang, 2013: Anthropogenic and Natural Radiative Forcing. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
Purohit, Palav, and Lena Höglund-Isaksson. “Global emissions of fluorinated greenhouse gases 2005–2050 with abatement potentials and costs.” Atmospheric Chemistry and Physics, vol. 17, no. 1, 2017, pp. 2795–2816. Copernicus