If we talk about the European one, which many have followed, for each economic sector there are limits set. Essentially, you have to emit below so many tonnes per whatever the measurable is for that sector—let's say per kilowatt hour—to be considered sustainable, but you have to do it with no significant harm. You have to show as well that you are not creating environmental or social harms in other areas, so that we don't run after something that is really green but creates damage in another way.
That's basically the structure the Europeans and most others follow, but, once again, it has to be specific to the local economic context. As we said earlier, defining “transitioning” is a critical role for the Canadian taxonomy.