I would guess you are looking for lifetime earnings, yes?
At present, mining engineering statistically pays better. Civil engineering is down at the moment, software engineering is up. Overall I honestly couldn't tell you which field of engineering to follow.
You obviously don't have a degree yet, so I'd be more interested in finding AN EMPLOYER that would be willing to employ you and put you through the degree, I'm currently a draftsperson that is being put through a Civil Engineering degree, so I'm guaranteed a job when I graduate. a lot of people can't say that.
Apply for jobs now, you don't need an engineering degree to get engineering jobs.