Scope and intensity

Some thoughts as I was preparing an executive briefing on Greenback's greenhouse gas emissions:

As previously described, GHGs are counted in three separate scopes. Scope 1 emissions are direct emissions -- physical CO2 (and other gases) that rise up directly from our campus. Scope 2 is utility emissions -- the gases rise up from utility stations, but they're created because of electricity (for example) that we use on campus. Scope 3 is indirect emissions -- for signatories of the ACUPCC, the most important ones are gases generated from commuting and from university-funded air travel.

So, in a nutshell, scopes 1 & 2 are about how we run our campus proper. Scope 3 is about how our campus interacts with (or causes our employees and students to interact with) the outside world.

Additionally, two types of "intensity" are often calculated. If you report your data to the ACUPCC, they'll publish not only your total emissions, but also your emissions per square foot of heated (interior) space, and per student FTE.

Reducing those two to nutshell size, emissions per square foot is largely about how efficiently you operate your buildings, while emissions per FTE is determined by how efficiently you utilize those same buildings. Each of these characterizations, of course, gets muddied by the fact that not all emissions originate from buildings -- some, for example, originate from cars and trucks. But, overall, these sorts of generalizations help put some meaning on what otherwise might just be abstractions.

If you think about it, it probably makes sense to calculate intensities based only on data for scopes 1 & 2. How far your students and employees commute, and what sorts of vehicles they commute in (the major determinants of scope 3 emissions), really have nothing to do with how many square feet of campus you've got. And commuting emissions really aren't related to student FTEs, either. A campus with 2000 half-time students has as many FTEs as one with 1000 full-time students, yet will have twice as much in the way of commuting emissions. (Actually, more than twice as much, since part-time students are less likely to live on or near campus than full-time students are.)

All of which, I guess, is a way of saying that calculating emissions by scope, and calculating emissions intensities, can help us to understand what general sorts of changes might have the most impact. But just as easily, some calculations (like scope 3 emissions per square foot of building space) can be totally meaningless. Or worse.

Still, it makes sense for the ACUPCC to require campuses to report on scope 3 emissions (even though scope 3 numbers are always estimates). It comes down to that question of how an institution interacts with the outside world. Of what sort of behaviors a college or university exhibits, or causes its campus community to exhibit. Of what kind of expectations we want to set. And what kind of example.

The analytic techniques that have been developed so far -- scope and intensity are the two most common -- are far from perfect. Each of them is likely to get refined or redesigned at some time in the future. But each is already good enough to serve as a line in the sand from which we can measure our progress.