Climate Impact of New Construction:
Embodied Carbon

Here we address the subject of embodied carbon in new construction and demolition. Consider this when evaluating the carbon footprint of demolishing and rebuilding in the proposed  HCA zone around Lincoln Station:

Article 3 is concerning from an environmental standpoint because it encourages developers to demolish usable buildings to build new ones.  Every time you buy and then throw away something “disposable” (a plastic bag, a paper plate) a new one is created somewhere in the world.  Similarly, if you demolish a house it goes straight to the landfill, and assuming there is still demand for houses, a new one will be created somewhere else.

The concern is that building houses generates an enormous amount of carbon emissions.  Manufacturing materials like cement and steel require high temperatures and have a huge impact on a building’s carbon footprint.  The carbon generated in the production of buildings is called “embodied carbon.”  

On average, a 3000 square foot house contains 54 metric tons of embodied carbon.  That is the equivalent of driving a gas powered car 154,000 miles or a hybrid car 208,000 miles.

Go ahead and check the calculations:

Average house embodied carbon:

193 kg co²eq/meters² of residential 
(this is conservative; other sources indicate wide variability, up to 1000 or more kg co²eq/meters squared for residential buildings)

1 Meter squared = 10.8 feet squared

So, average house = 17.9 kg co²eq/feet squared
or
54000 kg for 3000 square foot house = 54 metric tons

Source:
https://www.canadianarchitect.com/making-the-case-for-embodied-carbon-in-renovations/

Car Carbon Footprint based on miles driven:

Gas powered car is 350 grams/mile

Hybrid car is 260 grams/mile

Source:
https://climate.mit.edu/ask-mit/are-electric-vehicles-definitely-better-climate-gas-powered-cars

One may ask, "what if you are replacing an older building with a newer green building?"  It still does not make sense from a carbon footprint standpoint.  Renovating rather than demolishing and rebuilding is always the greener choice.  

The greenest building is the building that is already built.
Read more on this from Treehugger here.

Stop and Go Traffic along the Lincoln Road Corridor

Here we lay out the likely environmental implications of HCA compliance via Article 3 (aka Option C) with a particular focus on auto emissions from associated increased stop-and-go traffic on Lincoln Road.

There is no way to candy coat this: 650-800 new housing units concentrated around Lincoln Station will result in daily heavy traffic of the likes that the Lincoln Road corridor has never known. We will be able to count on long backups stretching at least from 117 to the Library,. Already, various traffic mitigations have been discussed, like a rotary at the 5-Corners Flowerpot. Still, the pressures on our small road system would be unavoidable. This means lots of idling cars.

The HCA and Carbon Emissions
The State requires that only 20% of the HCA re-zoned areas be within 0.5 miles of a transportation station.  Lincoln’s Article 3 was designed for a max build of up to 800 units, condensing 100% of rezoning around the train station.  Though presented theoretically as an environmentally-friendly solution with an emphasis on MBTA use, Article 3 in practice could actually be an environmentally unfriendly policy due to increased auto traffic, traffic jams on Lincoln Road, and unreliable MBTA service that will take billions of dollars and many years to fix.

Commuter Rail Use vs. Car Use

The commuter rail is infrequent and unreliable.  The current alert for Lincoln commuters is to expect 20 minute delays, and this alert has been on-going for many months. Only a select few have work situations that make using the commuter rail feasible.  Furthermore, Lincoln Station on the Fitchburg line is not wheelchair accessible. Combined, this leaves most everyone else largely reliant on automobiles for their transportation needs. Concentrating 100% of new HCA-zoned development at Lincoln Station will lead to even worse than current stop-and-go traffic down Lincoln Road, decreasing local air quality and increasing carbon emissions. 

Stop and Go Traffic

Stop and go traffic emits the worst kind of car pollution. The area around Lincoln Station will be host to emissions from commercial trucks making deliveries to The Mall, occasional diesel-powered trains coming and going from Lincoln Station, and idling cars related to up to 800 new housing units (with at least one parking space per unit by law).  Additional high density housing around Lincoln Station will result in a significant increase in stop and go traffic on Lincoln Road, and associated auto emissions will impact residents all along—and adjacent to—the Lincoln Road corridor.

No Guarantees, so Hedge Your Bets and be Pragmatic.

Unfortunately, it is going to take time for train service to improve.  According to the Boston Globe:  "The MBTA needs a gobsmacking $24.5 billion to repair and replace its decrepit track, stations, trains, signals, and other assets…. $8 billion is needed to repair the commuter rail system alone.”  Only when train service improves does it make environmental sense to do anything close to Option C's max build around Lincoln Station.

What Should We Do?  

One recently made suggestion by Lincoln's Planning Director to manage increased traffic along the Lincoln Rd. corridor is to build a rotary around the Flower Pot at the Five Corners Intersection of Lincoln Rd., Bedford Rd., Weston Rd., Sandy Pond Rd., and Trapelo Rd.  This seems pretty extreme for our small town's historic center. An incremental approach to development would be a more pragmatic policy.  

Instead of tying the town's hands through the intensive HCA rezoning proposed by Article 3, Lincoln should vote it down, and then rezone to do moderate development in the Lincoln Station area and distribute the remaining required HCA percentage to other parts of Lincoln as allowed by the law—there are many ways to comply, and Article 3 (aka Option C) is the most extreme version. A more practical approach allows for the possibility of adding more housing near the station later, without that additional growth being tied-in by the HCA mandate restrictions. Then, wait for the state to give an actual timeline for when train service will improve and study MBTA use before committing to more housing concentrated near the station.

Meanwhile, it's not environmentally conscious to give the highest bidding developers free range to build out up to 800 units with associated traffic and air pollution and leave existing residents to pay the cost with their health and wellbeing.

Light Pollution

Here we address light pollution in the context of Article 3's (aka Option C's) condensed rezoning.  Dark skies are critical to the survival of Lincoln's pollinators and wildlife.

Dark Skies
Larger scale development down Codman Road will bring more light pollution.  The parcels that now have trees and single family homes will be allowed to have buildings and parking lots covering 50 percent of the lot area.  Even the remainder is not protected from hardscaping and could include things like sports courts. All this will inevitably bring an increase in light pollution and environmental challenges.  

Why is this a problem?  Research has shown that artificial light affects many mammals and insects, disrupting circadian rhythms, distracting pollinators from their nighttime pollination routines, and discouraging smaller mammals from feeding due to concerns of being exposed to predators.  The solution for single households is to turn the lights off. However, for larger developments this is not possible for safety reasons.  

Lincoln has shown a commitment to creating pollinator pathways. No Mow May is one way to promote pollinators--but what do pollinators do at night?  Watch the following video of a talk about the importance of protecting our night skies given by expert Dr. James Lowenthal, hosted by The Lincoln Land Conservation Trust. 

Light pollution has been a topic of discussion since September, and we were told that residents would be told to close their shades as the solution. There should also be stricter regulations around the type of lights and their color temperature and brightness. Westford has shown care and intention in drafting its HCA Bylaws related to Light Pollution (Page 24: 

https://westfordma.gov/DocumentCenter/View/14019/Westford_Zoning_Bylaw_Section_810_MCMOD_2024-01-05_TC)

Preserving Mature Trees for Carbon Capture

Here we address the subject of carbon capture in mature trees. Codman Road and Lincoln Road host countless mature trees. Rezoning in areas that are less thickly forested would be more environmentally responsible.

Another issue in building where Article 3 rezones is the cutting down of mature trees.  Because of their age (80-100 year range), our trees in Lincoln are extremely effective in capturing carbon, and can continue to do so for 200 more years.

According to Edward K. Faison, a Senior Ecologist with Highstead (a conservation non-profit dedicated to increasing the pace of land protection in New England and beyond through science, sound stewardship and collaboration with diverse partners), "When compared to a 3” diameter tree, a 30” diameter tree at 10 times the width captures about 70 times the quantity of pollutants, including carbon monoxide, ozone, nitrogen dioxide and particulate matter."

For further reading on this subject, check out this article from the Arnoldia, the quarterly publication from Arnold Arboretum of Harvard University.

Many Massachusetts towns (including Concord and Cambridge) have tree bylaws protecting trees from being plowed down by developers.  Should Lincoln adopt one before giving over Codman Road to the free reign of developers? Should other locations in Lincoln that are not as thickly forested with mature trees be considered for rezoning instead? 

We don't need to reinvent the wheel.  In Westford's HCA Bylaws, great care is being taken to protect mature trees for this reason. (page 23: https://westfordma.gov/DocumentCenter/View/14019/Westford_Zoning_Bylaw_Section_810_MCMOD_2024-01-05_TC)

Is there any reason for Lincoln to delay in adding similar protections?  

Read a perspective on this subject by a local Lincoln certified arborist.