What’s the ‘sustainable level’ carbon footprint in the app based on? 

There’s both good news and bad news in estimating what a sustainable carbon footprint level per person and year would be.  

Let’s start with the bad news: Unfortunately, there’s no universally agreed upon number here. This is due to several reasons, such as the uncertainties in predicting future pathways, whether it’s the footprint by 2030 or 2050, or whether it’s in line with the 1.5°C or 2°C temperature goal of the Paris Agreement.  

Time for the good news! There’s plenty of studies out there that have done some estimations. The sustainable level we use in the app is the global per capita carbon footprint needed by 2050 to align with the 1.5°C goal of the Paris Agreement. So, how did we end up with 1 tonne CO₂e per person and year then? It’s an estimation based on several public and academic sources that estimate the sustainable footprint to be anything from 1 tonne CO₂e and 1.1 tonnes CO₂e to “as far below 2 tonnes CO₂e as possible” and even 0.7 tonnes CO₂e.