The Carbon Offset Potential of Campus Forests and Other Land
By Jennifer Andrews, Director of Program Planning and Integration, Clean Air-Cool Planet
(This article appears in the February, 2011 issue of The ACUPCC Implementer)
One of the questions that CA-CP still gets quite often as we support schools in their GHG inventories and climate action plans is, “What about our forests? Can’t we count them as offsets, since they are sequestering carbon?” You can read the initial response to that question in this article, previously printed in the Implementer. We have since worked with Chatham University (Pittsburgh, PA) and the US Forest Service to explore in more detail the role campus forest or other green space might play in the journey toward carbon neutrality.
The results of that collaboration can be downloaded from CA-CP’s webinar archives. They include a sample Campus Tree Policy, as well as a great deal of useful information on how to use the Forest Service’s online “I-Tree” tool to accurately assess the ecosystem benefits provided by the forest, including carbon sequestration and fossil fuel avoidance through the shading of buildings. So far, though, our work with these partners has only scratched the service of the broader question of how campus lands might actually offset the institutional carbon footprint. Indeed, there has been relatively little work in this arena overall.
One reason, of course, is that most ACUPCC signatories have been—appropriately—focused first on mechanisms for reducing or avoiding their actual campus emissions, and simply haven’t yet gotten to the question of how they will offset the emissions they can’t reduce, except in the broadest of terms. (For example, many schools have gotten so far as to express a preference in their climate action plans for helping create new, local offset projects rather than purchasing offsets off the open voluntary market—a preference which would of course make projects involving campus land a subject of interest.)
The second reason is that the land-based projects or practices so far identified as having the highest potential to serve as viable carbon offsets come with a couple of thorny sticking points. A number of agencies, firms and schools are working to overcome these barriers, which we’ll explore in a bit more depth in a moment, but there is still some significant innovation and refinement needed to ensure that these potential carbon offset mechanisms can be credible, effective and viable for ACUPCC signatories.
The first three mechanisms by which campus lands might be employed as carbon offsets are reforestation, afforestation (in other words, planting new forests on land that was not previously forested), and enhanced forest management (revamping existing practices of care and harvesting to keep trees growing for as long—and only for as long—as they increase their carbon uptake by a certain rate annually.) All three are offset techniques for which there are methodologies in the existing offset protocols and programs (for example, CAR and VCS, both featured in other articles in this edition of the Implementer, have standards for afforestation and/or reforestation projects). These methodologies are meant to address issues of measurement and credibility, since without such standards the way in which forest carbon sequestration is measured and credited could be too subjective.
Two additional issues particularly relevant to these kinds of forest-based offsets are synchronicity and permanence. Both of these are characteristics cited in the ACUPCC Offset Protocol as important elements of acceptable offsets. Synchronicity—the idea that the carbon reductions (or avoidance) that occur as the result of an offset need to occur in roughly the same time frame as the emissions they are offsetting, in order to be valid—is naturally a question if one is creating new forests now to offset current emissions, since the trees in that forest will take years, even decades, to reach their full sequestration potential. And permanence is always a hard qualification to establish for forest projects, susceptible as they are to pest infestation, fire or other natural disasters that could very rapidly and unexpectedly re-release the carbon sequestered there (though there are measures specified by VCS, for example, to account for this risk.).
These roadblocks are not stopping schools from looking at the potential of these types of forestry projects (on their land or even on the land of potential partners in the community), but it has meant that there are few if any such projects that have been implemented to date. Cornell and Duke universities are a couple examples of schools that have stated their intentions to explore the potential for such projects, or have actively begun researching them, but to date few if any schools have actually implemented such a project on their own lands, and only a handful have invested in such projects in other locations (Temple is one, Connecticut College is another).
A third potential offset mechanism that is getting a hard look by a number of ACUPCC schools (and others) is biochar. Biochar is similar to charcoal, except that instead of being used as a fuel, it is applied as a soil amendment and used to effectively sequester carbon in the soil. It is produced by subjecting biomass to pyrolysis, or combustion at high temperatures in the absence of oxygen. The process of pyrolysis can actually be optimized to generate biochar or to generate biogas. The implication is that schools producing biomass (wood chips, but also corn stover, switchgrass, even yard waste) might employ pyrolysis to create biochar from that biomass—which can then be used both to improve agricultural soils (as an alternative to chemical fertilizer) and to sequester carbon—thus creating a carbon offset. (It’s also theoretically possible to use biochar in energy systems that currently rely on coal combustion, or, to substitute the biogas created through pyrolysis for natural gas, or even a liquid transportation fuel in some applications.)
Much research is currently underway comparing the life-cycle use of energy to create biochar with the amount of energy use (and GHG emissions) that biochar can avoid or reduce. The results of those analyses differ depending on the type of feedstock used, but in general the results look quite promising. Beyond the technical questions of biochar’s energy and carbon balance, the economic viability of producing and using it (as either a fossil fuel substitute or a soil amendment to sequester carbon) is still being worked out. While many experiments at a small scale are underway, there is as yet no commercial-scale biochar production, largely because the economics are not yet highly favorable. Nevertheless, this is one potential offset technology that you should expect to be hearing much more about in the coming months and years.
Jennifer Andrews is Director of Program Planning and Integration at Clean Air-Cool Planet (CA-CP), whose Consumers Guide to Carbon Offsets was a ground-breaking publication in 2006 and continues to be an important resource on the promise and pitfalls of carbon offsets, and the basics of offset quality. Jenn was a member of the working group that produced the ACUPCC Offset Protocol in 2008.
 See, for example, the study published by Reberts et al in Environmental Science and Technology last year: http://www.citeulike.org/user/kmscow/article/7165547, or the presentation of their research: http://www.cns.umass.edu/biochar09/presentations/Roberts.ppt