Meaning of “sort through” in this context?

Here is an excerpt from the book called I’m Right and You’re an Idiot (by James Hoggan).

For example, environmentalists tend to see things in terms of black and white, good versus evil, “so they can sidestep dealing with the really messy reality of sorting through difficult changes.”

In this context, what is the meaning of the phrase “sort through”?

I’ve looked it up in the Macmillan Dictionary, which says it means “to look at a lot of things in order to find what you want or need.” However, in this case, I’m not sure if the meaning is quite fit in the context. Can “sort through” be used as an alternative to “sort out” or something?