E.S. seminar poses carbon question

Last Thursday, Feb. 11, the seven seniors of the environmental science 401 seminar (taken during this Winter Term) presented their research findings about the effectiveness of forests at sequestering carbon. The students’ message about the College, the environmental studies program and its relationship with the greater Vermont community questioned the viability of the biomass facility.

For the first time this year, the ES department offered its senior seminar during the winter term. For Alice Ford ’10, ES 401 was a huge success.  Although the compression of all that research into four short weeks was obviously stressful, she said that “having the seminar during J-term was great. It let us concentrate on just our research without having to do, well, other classes.”

In another change this year, the ES department decided to create a common theme among the three seminars (fall, winter, spring).  All three groups of students will focus on energy.

Specifically, the Winter Term group researched carbon sequestration and storage. Ford said that, in general, they wanted to study “the procurement standards that the College uses for biomass so that they consider more of the forests’ sequestration potential.”  “Procurement standards” is just the scientific way of saying, “how we go about getting” the biomass (i.e. forest material like trees, leaves and brush) that the College burns at its plant.  The ES students believe that the way in which we harvest biomass material is affecting the carbon storage potential of the forests. Trees take in carbon dioxide, store the carbon inside the wood, and give off resultant oxygen.  Forests therefore store a lot of carbon within them.  This process of taking CO2 from the atmosphere and storing it is called carbon storage.  Carbon sequestration is actually taking the CO2 and eliminating it altogether. The ES 401 students collected data on how much carbon a forest can store and how different harvesting practices affect those numbers.

This research led the students to a number of interesting conclusions. The students were able to come up with some rough estimates of the potential carbon storage of Middlebury lands. The 1,297 hectares of land that Middlebury owns both near campus and at Bread Loaf is capable of storing between 323,000 and 354,000 tons of carbon.  They calculated that as the forest grows, untouched, carbon storage increases by about 10,000 tons per year. For reference, the Middlebury Web site indicates that the biomass facility is meant to decrease the College’s total carbon emissions by 12,500 tons, a fraction of the amount being stored in its lands.  Unfortunately, the estimates presented by the group were extremely rough.  There does not exist enough data to make accurate estimates.  The students were forced to use data from other types of forests and equations meant for other places in the United States.

Ford explained that “this work needs to be done. With more resources, we could have done a lot more.”  In this regard, one of the other things students in the ES seminar had to learn was “how frustrating it is to research modern ES concepts.”

The biomass facility on campus is the jewel of the College’s sustainability program, but both the fall group and these Winter Term seniors agree that Middlebury’s goal to become carbon neutral by 2016 cannot be accomplished with the biomass facility running as it does now. While previously biomass gassification was thought to be nearly carbon neutral, that opinion is changing — beacause, while burning biomass is much better than the burning of fossil fuels, it is still a deeply flawed process, according to students of ES 401.

Their study of carbon sequestration indicates that naturally growing forests are the optimal way to store carbon.  Any thinning, harvesting, or managing in general will hamper the forest’s ability to store the carbon.  Carbon storage in the forests is a naturally occurring process that has been regulating the CO2 levels in the atmosphere since the dawn of time. However, as more forests are cut, the gap between the amount of CO2 being released into the atmosphere and the carbon being stored widens, increasing the amount of CO2 in the atmosphere, and thereby contributing to be a major source of climate change.

Carbon storage, then, must be considered in any calculation of carbon neutrality.  Ford said that any cutting of trees results in the “missing out on potential carbon sequestration.”  Those trees could be storing carbon, and cutting them is the same as releasing that same amount of potential into the atmosphere. Also, the soil, which is the best store of carbon available, is exposed to sunlight by the cutting of trees, which releases even more carbon dioxide into the atmosphere. The procurement standards that the seminar put together are a way of optimizing the carbon storage of the forests.  Things like selective cutting, observing longer harvesting cycles, and managing the ages of the trees would maintain higher levels of carbon storage while still enabling the plant to obtain biomass for energy. Still, the best way to maintain carbon storage is through “passive management.”

Meghan Blumstein ’11, who attended the colloquium, described the presentation as the “best example at Middlebury of community outreach,” adding that “the ES department makes an effort to connect their research to the greater Vermont community.” Dale Freundlich ’10 was likewise encouraged by the “connection with the community, which is often lacking at the College.” This seminar worked with Vermont Family Forests in an effort to educate farmers about carbon sequestration and set up procurement standards for community farmers.  The farmers that are part of VFF are environmentally conscious.  Unfortunately, according to Lizzie Horvitz ’10, “landowners are not aware of carbon sequestration.”  There is simply not enough information or research, especially on the local level because so much of the storage depends upon variables such as the specific soils and trees found in the area. Middlebury needs to research the economics of biomass procurement and into the exact amount of carbon storage potential of its lands to find out which behavioral changes can serve its goal of carbon neutrality.

In addition to Ford and Horvitz, this Winter Term’s ES 401 seminar included: Clare Crosby ’10, Chris Free ’10, Charlie Hofmann ’10, Emily May ’10, and Roz Vara ’10. The course was led by Professor of Biology and Environmental Studies Steve Trombulak.