Looks like the economics of divestment makes much more sense than the climate benefits at this point. If Somerville waits till 2050 they will certainly lose money... Even Better than divesting, perhaps they should invest this money into Clean Energy ETF's like TAN or clean energy plays like Enphase ENPH which has a 20,000% 5yr return?

Others are dropping fossil fuel toxic assets at an accelerated pace:
"Investors, foundations, universities and governments pulled their assets from fossil fuel companies in record numbers in October. ... The decades-long push to get large investment funds to pull their money from destructive oil, gas and coal has made several major leaps forward in the past month. One of the biggest occurred Oct. 18 when the Ford Foundation, a nonprofit built on profits from the combustion engine, announced it would divest its endowment from fossil fuel companies." https://www.resilience.org/stories/2021-11-16/the-divestment-movements-big-month/

Renewables set to take over rapidly despite policy: Rapid transition to renewables inevitable based on economics, find Oxford study
Paper: https://www.inet.ox.ac.uk/files/energy_transition_paper-INET-working-paper.pdf "Why do the major groups publishing energy forecasts consistently undershoot the progress of energy transition? For decades, public sector agencies, oil industry groups, energy industry consultancies, and even environmental nonprofits have been consistently too pessimistic in their outlooks. So why is it that standard energy forecasting models keep getting transition wrong? ... A group of researchers at Oxford University may have an answer to that question with a study they recently published on the future trajectory of the energy transition. The problem, they say, is that standard models don't realistically account for learning curves in manufacturing, and exponential growth in deployment as it relates to transition. Their new approach shows that future cost and deployment curves can be predicted quite accurately for energy transition solutions like solar panels, wind turbines, batteries and hydrogen electrolyzers." --Youtube video of the researchers talking about their work https://www.youtube.com/watch?v=W-jlDPUw2Bc --Listen to the newest episode of the Energy Transition Show from Chris Nelder, he interviews the author. https://podcasts.apple.com/us/podcast/the-energy-transition-show-with-chris-nelder/id1042713378

Why clean energy is set for high returns going forward: "At the end of 2019 Solar stocks had had their 3rd straight year of outperformance over traditional energy companies. During the stretch of Jan 2017- December 2019 The Invesco Solar ETF (TAN) outperformed the SPDR Energy Sector ETF (XLE) by over 100%. 2020 continues that outperformance with TAN up over 100% Year-to-date vs XLE down 9%.* Meanwhile traditional oil company stocks remain mired in poor performance... The movement to ESG investing may be partially responsible for the differing stock performance. The ESG Investing movement is gaining strength. Younger investors are demanding investment solutions that are both responsible and profitable. “Socially responsible investing” is trending on Google and it has been mentioned much more frequently in the financial news in 2020. This is a good thing: https://www.nasdaq.com/articles/sun-shining-on-this-solar-etf-before-election-2020-10-20? https://www.etf.com/TAN#overview

So, If Somerville has already divested, hopefully, they won't miss the boat and invest in Clean Energy which is set for explosive growth... Even Storage:"Terawatt-hour of energy storage by 2030: BloombergNEF forecasts boom in installations" https://www.energy-storage.news/terawatt-hour-of-energy-storage-by-2030-bloombergnef-forecasts-boom-in-installations/?