The carbon footprint of astronomical research facilities has become a critical issue in recent years. Its measurement, in terms of carbon dioxide equivalent, CO2e, serves to understand the behavior of these organizations and their individuals and, in this way, efficiently manage resources.
The carbon footprint of astronomical operations, in general, is dominated by the gases generated during the construction of the enclosures, and by subsequent operations, strongly influenced by the high consumption of electricity, fossil fuels for the transportation of collaborators and visiting astronomers, and maintenance supplies.
According to an article published in April 2022 in the prestigious scientific journal Nature*, astronomical observatories have a large carbon footprint. According to the authors, the Earth can absorb 2 tons of CO2 per year per person. Considering the available global astronomical infrastructure, including space telescopes, ground-based observatories and research institutes, the average annual emission of the research infrastructure per astronomer is 36 ± 14 tCO2 (tons of CO2). To become CO2 neutral, astronomical activity needs to reduce its CO2 footprint by a factor of between 10 and 25 in the coming years.
So, if astronomical observatories began operating in Chile more than 50 years ago, is it possible now, several years later, to seek mitigation measures?
Leopoldo Infante, director of Las Campanas Observatory (LCO), was one of the readers of the article published in Nature, in which LCO was not included. Therefore, he set out to determine an indicator of the impact of LCO’s operations, measure the carbon footprint produced and work to reduce it. With this in mind, she sought out a group of specialists who, in addition to determining the impact on climate change, would propose mitigation measures.
This is how Anrryeth Thenoux, Paloma Villagrán and Josefina Méndez dedicated their Industrial Engineering degree project at the Universidad Católica del Norte, in Chile, to this topic. Using the Life Cycle Assessment (LCA) methodology, the young women designed and implemented -using the Python programming language- a modeling that determined the carbon footprint of LCO from 2019 generated by stationary and stationary combustion and electricity consumption.
In this paper, as in the Nature article, the CO2 footprint was assumed to be dominated by two factors: construction and operations. Following the line of the article, for the case of the LCO Magellan telescopes, activity factors of 240 tCO2e per million dollars were considered for construction and 250 tCO2e per million dollars per year for operations. For the emission factors, a base of $126 million was considered for telescope construction, and $7 million for annual operations. The footprint per article published between 2001 and 2022 was summed (2751 articles) and, finally, to calculate the footprint per author, the number of unique authors who signed at least one article was estimated to be 10924.
Thus, it was obtained that the carbon footprint of LCO in 2022 amounts to 593 tons of carbon dioxide equivalent, with business travel contributing 49%, followed by 17% due to the daily mobilization of personnel, 12% for mobile combustion, 10% for stationary combustion, 8% for the use of non-renewable sources and finally 5% corresponding to domestic air travel.
These numbers are low, when compared with those published in Nature magazine and with other observatories installed in Chile, mainly because the operations of these types of scientific institutions are dominated by energy, and for the last three years, the Las Campanas observatory has been supplied with energy by the Colbún company, which uses renewable sources.
“In the cases of renewable energy or not, the electrons that come through the cables are the same, but if we buy from companies that have renewable plants we exert pressure so that the generation of energy, in general, changes”, emphasizes Infante. The astronomer is emphatic in pointing out that this is not a purchase of carbon footprint bonds, a fairly widespread method of compensation in companies that seek to reduce the impact of their carbon footprint by paying organizations that contribute to the removal of greenhouse gases through different projects. “Our energy comes from renewable sources and not from others, so we can say that our energy is zero emission, the carbon footprint on the energy side is practically zero,” Infante emphasizes.
The results of the study indicate that LCO should eradicate the carbon footprint from electricity, and 80% from mobile combustion, by adopting electromobility in the Mountain, where the telescopes are located and most of the operations are carried out, by 2040.
“We also suggest that LCO take an active role in combating climate change and its effects by forming a team dedicated to this issue,” emphasizes Paloma Villagrán. “We hope that, within 18 years, LCO will be moving towards carbon neutrality and making strategic decisions aimed at sustainability management,” adds Anrryeth Thenoux.
To advance on the road to carbon neutrality, LCO is looking into making more remote observations, with astronomers observing from various parts of the world, connected via the internet and supported by observatory staff. This would generate a significant decrease in the carbon footprint produced by international travel. The exact percentage has not been defined, and will be done after receiving the conclusions of the research conducted by Thenoux, Villagrán and Méndez.
By 2040, LCO will be looking to make a shift in the vehicle fleet from benzine and petrol to electric. “That’s also going to be significant. There is another series of carbon footprint mitigation measures at the local level, for example, kitchens, internal movement, use of bicycles, etc.,” says Infante.
“Reaching neutrality is difficult, but reaching a low percentage is possible. For that we have to take important steps now,” concludes Infante.
* Knodlseder et al., Nature Astronomy, Vol 6, April 2022, 503-513.