Businesses typically measure sustainability either by counting reductions specific to each domain (BTUs, gallons, kWhs), or they equate sustainability with carbon or cost reductions (typically gained through efficiency improvements).
In the past, governments have tended to measure how well they are doing in any particular policy area by counting the amount of money they are spending on it.
Marine scientists measure its abundance by dragging a sledge equipped with video cameras along the seabed and counting the number of holes (a well-maintained burrow being the sign of a happy prawn).
Global cement giant Cemex took the opportunity to announce a green measure at the climate change talks going on in Cancun, Mexico: its very own carbon-counting tool.