If your institution has signed the American College and University Presidents' Climate Commitment (or, perhaps,even if it hasn't), somebody on your campus periodically inventories greenhouse gas emissions. Technically, there are six "Kyoto gases" that should be inventoried, but for most campuses only three really matter -- carbon dioxide, methane, and nitrous oxide. So the short answer to "what gases do you inventory?" is a three-item list. But the longer answer, and the more complex one, is more important.
Unlike the three-item list (which is pretty much universal for institutions of higher education if not for participants in other industrial sectors), the longer answer will likely differ for every college and university. To figure out what the long answer should be, you first have to think about three fundamental questions.
First, how much of your institution do you want to inventory emissions from? The most common reflexive answer is "all of it", but nobody really does that except, maybe, for the very smallest colleges. Most institutions have campuses, but they also conduct activities away from campus. And they may very well own or lease facilities (offices, research labs, satellite classrooms, residential space) off campus. If you lease the space, you may not control things like heating and lighting, and you may not get detailed billing (accounting, in more than just a financial sense) information. These off-campus facilities generally don't account for a lot of square feet, nor for a lot of GHG emissions. Thus, most campuses ignore them under a sort of informal de minimus exception. But if you're going to leave them out of your GHG inventory, it should be as the result of a conscious decision and it should be fully disclosed.
Second, how much of the GHGs which are emitted because your institution exists -- as a result, directly or indirectly, of your existence and operation -- do you want to take responsibility for? GHG accounts are generally categorized into three "scopes":
- Scope 1 emissions are those which physically arise from campus -- gases emitted directly, most often as a result of the combustion of fossil fuels. Think of them as "tailpipe or smokestack" emissions. Drive a car on campus, generate Scope 1 emissions. Turn up the thermostat in a building with a gas-fired furnace in the basement, generate Scope 1 emissions.
- Scope 2 emissions are those which physically arise from the facilities of public utilities, but which are generated as a direct result of utility demand that originates on campus. They're still arguably smokestack emissions, but the smokestack is no longer on your campus. Turn on an electric light, generate Scope 2 emissions. Turn up the thermostat in a building with electric heat, generate Scope 2 emissions.
- Scope 3 is everything else.
Most campuses do a good job of quantifying emissions in Scopes 1 and 2. It's time-consuming (especially until you get a process worked out), but it's not especially difficult.
Most campuses (Greenback included) do a pretty poor -- which is to say, incomplete -- job of quantifying Scope 3 emissions. The reason is simple. For Scope 1 and 2 emissions, you know how much fossil fuel you burned, you know what types of fuel, you know how many kilowatt-hours of electricity you used, you know the factors, you can do multiplication. But for Scope 3, you have none of that information.
Scope 3 emissions include GHGs resulting from:
- Travel away from campus by sports teams, admissions staff members, research faculty, staff and students
- Commuting to campus by faculty, staff and students
- Travel to campus by alumni attending Homecoming and other events
- Travel to campus by alumni and fans attending sporting events
- Travel from home to campus (or nearby) for residential students
- Production of food served on campus
- Production of beer consumed on campus
- Production of non-durable goods (paper, ink, pencils, books, art supplies, drafting supplies, etc., etc.) consumed on campus
- Production of durable goods (desks, chairs, computers, lamps, calculators, extra-long fitted single bed sheets, etc.) bought specifically for use on campus
- And more, and more, and more
Trying to estimate most Scope 3 emissions accurately seems like a fool's errand and, for many entities preparing GHG inventories, it would be. But how to handle Scope 3 emissions depends on the answer to the third fundamental question: Why (to what end) are you estimating GHG emissions at all?
Corporations which publish GHG inventories so that they can publicize emissions reductions and burnish their images have no interest in inventorying Scope 3 emissions. For starts, they're interested in telling the story of how little in the way of GHGs they're emitting, not how much. But perhaps more important, corporations recognize that they have no control over Scope 3 emissions, and so no ability to reduce them. Whether corporations bear an ethical responsibility for emissions which, while falling in Scope 3, are still created as a result of the company's existence an operation is another topic.
Nations which estimate GHG emissions for the purpose of demonstrating compliance with international agreements (or for any other purpose) generally limit themselves to Scope 1 emissions. For an entity which defines itself (at least technically) in terms of geographic boundaries, limiting inventories to Scope 1 sort of makes sense. After all, emissions which for a campus or company might fall into Scope 2 or Scope 3 will, when we're looking at a whole country, generally be absorbed into Scope 1. Much travel and the activities of most public utilities are contained within national borders, so the general practice is to ignore exceptions to that rule. Whether nations should take responsibility for emissions created as a result of foreign activity undertaken to satisfy domestic demand (like, for example, GHGs from Chinese manufacturing of goods destined for the USA) is currently under discussion. (But don't hold your breath. US politicians love to point out that we're not the number one emitting country any more under current GHG accounting practices.)
Counties and municipalities which count GHG emissions generally do so in an honest attempt to measure their local impact on climate change. They're more likely than corporations or countries to try to get a handle on Scope 3 emissions, and through activities like land-use planning they have at least some indirect ability to affect Scope 3 emissions trends. Some of the better municipal studies I've seen estimate that as much as two-thirds of emissions for which community members are responsible actually occur outside the borders of the community itself. That's a pretty significant share -- for each 1 pound of GHG a community emits locally, it causes 2 pounds to be emitted somewhere else. What's important, then, isn't so much the elephant in the room as the two elephants just over the horizon.
So what does this mean for GHG inventories of university campuses? Well, for starts, I suspect that the "one here, two somewhere else" rule of thumb becomes more like "one here, three or four somewhere else", since municipalities and counties subsume a greater portion of the support services their inhabitants consume than do campuses. And partially as a result of that, I'd say that estimating -- and getting students involved in estimating -- Scope 3 emissions resulting from the existence and operation of the campus is key to educating for sustainability. It's not that the estimates generated can be used to baseline GHG reduction efforts, particularly; schools have very limited abilities to decrease most Scope 3 emissions, and even less ability to measure the impacts of any reductions achieved. It's more about developing a conceptual understanding within our graduates of just how their behaviors -- particularly, their consumptive behaviors -- contribute to the problem of global climate change. And about helping them to consider the impacts of their actions, even when those impacts occur somewhere over the horizon.