Naturally there are quite a few of questions of the type "Which one is more sustainable, x or y?" or "What is best for the environment, a or b?" - the most recent being
As far as I understand a lot of these questions can only be answered with thoroughly conducted life cycle assessments which are not necessarily available.
But nevertheless, a lot of information is very specific to one system (in terms of the geographic location, temporal aspects, the state of technology, recycling strategies of countries, the nature and composition of in- and outputs of the system, the legislation and so on) and may not be transferred to other systems of similar nature.
This is probably even more difficult if the person asking the question does not specify several aspects like "sustainability" (which can basically mean anything) or several methodological parameters commonly defined in life cycle assessment studies (the boundaries of a system, the impact categories chosen, etc).
My questions therefore are;
Should we demand more specifications (especially when the question is asking for sustainability) or leave this up to the person answering? and
Should we be more technical (such as referring to how representative a cited study is in the context of the question) when answering, pointing out the limitations of such studies? (for my understanding it seems that most people are not necessarily aware of that - which is not surprising given the complexity of production systems and even the life cycle methodology).