7 Ambition and hope - two ways to look at the global carbon budget

There are two ways, how we can look at the global carbon budget. On the one hand, we should set ourselves an ambitions target, doing our utmost to prevent climate change from becoming worse. Translated to our choice of the carbon budget, this would imply we should select a very ambitious target with a low warming limit and a high likelihood of staying below this limit.

As you might have seen by using the app from the previous section, such a choice implies a very small carbon budget, which implies that reaching this target is extremely challenging and can only be done by heavy cuts of emissions in very little time. This perspective might lead some people to think that it is too late anyway. However, there is a second perspective, which helps against adopting such a pessimistic view: Even if we select one of the higher carbon budgets from the table, they imply still a comparatively high likelihood of preventing global warming from surpassing the 1.5 to 2 degree limit.

For example, the 900 Gt budget would imply a 17 % likelihood of staying below 1.5 degrees C. This is low, but not nothing. However, it would also imply an above 80 % likelihood that we do not surpass the 2 degree limit, which is the upper bound of the Paris agreement. This is actually quite something. So if we select an ambitious target, but our actions in the end only reach one of the less favourable targets, we still have a non-ignorable chance of preventing much more catastrophic climate change!

Compare this to a medical procedure in which the patient has a real chance of avoiding a catastrophic outcome. The person would probably do their utmost, provided that there is a chance of survival. Being hopeful that it can be done is the best way to look at this. And hope can best be created through action!

Now that you know how much the world as a whole can still emit, in the next part of this mini course, you will see what the global carbon budget implies for country-level carbon budgets.