The significance test is inevitably complex because it depends on the specifics of the circumstances. Hoping to have a simple answer that can simply be quantifiable is attractive but I don't think it's practical. The term has certainly been abused, but the better way around that is to focus assessment on comparison of the reasonable options available in the two alternatives within the project concept. So what you'd be doing is openly judging according to explicit criteria, which should include the full suite of sustainability criteria that our colleagues have suggested. If you compare the relative merits when looking at the long-term legacy of undertakings, you will be less likely to get snarled in this legalistic question about whether you've crossed the boundary into significance or not, which isn't the issue. The issue is whether we get desirable projects that will leave a positive legacy.
On November 3rd, 2011. See this statement in context.