Carbon footprint
A quantitative estimate of the total carbon footprint for the MIT Kavli Institute for Astrophysics and Space Research (MKI)
We realize that astrophysicists at MKI contribute a significant carbon footprint through their use of large off-site facilities such as NASA satellites or ground-based telescopes in Chile and elsewhere that are not included in the estimate above, and which has been estimated to be around 40 tCO2e per astronomer in a world-wide average. In addition, there are emissions more directly related to MKI activity: office and lab heating and cooling, travel etc. that we will attempt to quantify below.
This estimate is based on a survey of travel and commuting patterns for our 150 person workforce, utility consumption in electricity, heat (steam + natural gas), and chilled water cooling of the physical plant.
Each of these was independently evaluated over a one-year interval during 2018-2019 before the COVID-19 scale back of campus research and teaching. Exact start and end dates varied for the different sources considered according to how data were collected. Our best estimate is that MKI produces 1826 metric tons of CO2 equivalent (MTCO2e) per year, or 12 MTCO2e per capita, per year.
Distribution to MKI's carbon footprint in CO2 equivalents. Data sources are somewhat inconsistent and convert different green house gases to "CO2equivalent (CO2e)" in different ways, so there is a small uncertainty on the relative contributions, but it is clear that building heating/cooling and air travel dominate.
The largest contributor is from heating and cooling, especially in the Ronald McNair building which houses a majority of our staff. Heating and cooling (chilled water) is supplied by MIT's central utility plant, a natural gas powered co-generation plant. While using both the electricity and heat from a co-generation plant is more efficient than buying electricity separate from a utility, it is still powered by fossil fuels. The McNair building itself was constructed in the 1960's , and still has mostly original, leaky single pane windows and little insulation. Thus, energy use is dominated by heating in winter and cooling in summer, milder winder weather in the 2020's has reduced heating needs compared to earlier years.
Greenhouse gas emissions from MKI's operations in the McNair building.
Air travel comprises about one third of the total carbon footprint and is dominated by conference travel and visits to collaborators. Since COVID, much of our observing at the Magellan telescope is done remotely, reducing long-distance air travel and review panels and time allocation committees have moved to video-conferencing. We encourage travelers to consider the possibility of remote participation, train travel, or combining multiple trips. MKI equips meeting rooms to participate in or host virtual meetings and conferences.
MKI’s computing cluster consumes both electricity and chilled water. While the total cooling load of the cluster is difficult to isolate accurately, if one uses standard ratios of total-to-computing power the implied footprint of cluster computing and cooling approaches 200 MTCO2e / year.
MKI has already realized a 20% net reduction in carbon footprint relative to 2014 levels, through MIT’s purchase of offsets from a solar farm in North Carolina. To reach 2030 targets set by MIT (which meet or exceed the US Nationally Determined Contribution in the Paris Accord) a further reduction of 15% below present levels, or 220 MTCO2e per year, would be required. This goal could potentially be achieved by replacing the single-pane windows and their deteriorating wood frames on the Ronald McNair building’s North facade, together with reduced emissions caused by pandemic-induced changes in commuting patterns and air travel.
Clearly, a lot of work remains to be done to reach the goal of environmentally sustainable research.