Im taking a Sustainable Engineering class right now and a big focus of the class has been widening the defined "system" your analyzing to include the environmental impacts made by processes. (By doing this many hypothetically profitable plants/processes are not actually profitable due to their costs that were often neglected in traditional analysis.)

I was curious to hear if there were any accepted methods for widening the "system" into the future, in order to somehow quantify the benefit/costs of current decisions on future generations. Like is there some sort of "Law" where the costs and benefits "decay" the farther in the future we look and then we can "integrate" this to get the total cost/benefit of the decisions?

Also there would obviously be massive uncertainty involved so maybe it would be more of a statistical EV calculation than an integration?