What is a “tonne” of CO2?
It can be tough to wrap your head around “a tonne of CO2”. We don’t often think about gases having mass or weight. So what does a tonne of CO2 look like, anyway? An art installation at the 2009 UN climate talks in Copenhagen attempted to tackle that question. CO2 CUBES: Visualize a Tonne of Change was created by Millennium ART in partnership with the United Nations Department of Public Information, Google and YouTube. The 3-story-tall cubes were made from used shipping containers and had two sides covered draped with screens projecting images and videos. The idea was to help people visualize exactly what one tonne of CO2 “looks like” in volume: 27 feet, cubed! (Photo above by PUSH_ARCHITECTURE.)
When we talk about how many tonnes of CO2 (actually CO2e in this case) under management by our clients, we know that huge number doesn’t mean much out of context. That’s why we break it down into cars, hot air balloons, and households.
For our cars calculation, we use a figure from the US Environmental Protection Agency’s Greenhouse Gas Equivalencies Calculator. It’s a really useful tool for converting tonnes of CO2 into meaningful equivalents, like cars or trees or even BBQ propane tanks. We divide our total CO2 under management by the CO2 emitted by an average personal vehicle in one year (5.23 metric tons CO2e) to get the equivalent number of cars.
For the equivalent CO2 in hot air balloons, we convert the tonnes of CO2 to volume (like the CO2 CUBES project did), and then divide that figure by the average volume of a hot air balloon (2,832 cubic metres).
To get the equivalent homes, we use data from BCStats, part of the British Columbia provincial government, about energy use in BC homes. We take our total CO2 and divide it by the CO2 emitted from heating a typical BC home for one year (2.4 tonnes CO2e).
We hope these equivalencies shed a little light on what “a tonne of CO2” actually means… What equivalencies would you be interested in seeing or learning about? Did I just set a record for mentions of “CO2” in one post?