In this short-form post I hope to explain personal reservations I have regarding pursuing careers in existential risk reduction, specifically how I struggle to recognize personal positive impact and how this might impact my motivation. The main reason I am posting this is to either be referred to methods to solve my problem or to hear from personal accounts as to how people have maybe dealt with this. 

The importance of preventing existential risk is very clear to me, and that one can provide a lot of positive  impact with such careers is too. There are ways of analyzing and ranking said risks I am aware of, and ultimately (to put it shortly) the catastrophe that poses the risk will or will not happen. Now, however naïve this might sound, I struggle to see how you can even come close to analyzing one's personal impact in the lowering of such a risk (especially for the ones considered big, with thus quite some resources and people working on them).

To me, EA in one sentence is: maximizing one's positive impacts, and working on existential risk reduction seems to me to have a positive impact, but the magnitude will always remain undefined (on a personal level).  Especially when compared to earning to give, where the impact one provides with donations is always quoted, an average of course, but nonetheless this provides a good idea of the positive impact created. As such I do not know if I can keep pursuing maximization of my positive impact and remain motivated about it if I will never have a clear idea of how much positive impact that really is.

I hope I have been able to properly express myself, and hope someone has a solution to my problem (i.e. have a better idea of one's positive impact) or how to deal with that uncertainty and remain motivated.