How do you measure everyday sustainability?

When you reduce your food intake to lose weight, you can track your progress on the scale.  When you reduce your expenses so you can pay off a debt or save for something you want, you can track your progress by the change in the account balances.  Watching these changes gives you an emotional reward for giving up something to make a positive change.  How do you measure the effect of your small everyday sustainability actions to keep yourself encouraged and feel as though your actions make a difference?  That’s a little harder.  Very few of us would be inclined to keep a spreadsheet to track each time we bring our own shopping bag or use the stairs instead of an elevator.  However, these small actions do add up and are worth doing.  Other than spreadsheets, there’s really only one idea I came up with for tracking your sustainability efforts to stay encouraged. Occasionally, I stop and think back 5 or 10 years.  What new sustainability habits have I started since then?  How has my diet changed to become more earth-friendly?  Have I purchased a more eco-friendly car or appliance?  What single-use items do I no longer use?  Have some of my friends or relatives changed their habits because of information I (gently) provided?  Comparing my “sustainability lifestyle” now to several years ago shows me that I have indeed made many useful changes.