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Aim higher, from just carbon neutrality towards closing the loop, saving money & natural resources and creating jobs at the same time.



Carbon neutrality is an important target. In an world faced only the challenge of climate change, this would also be enough. Unfortunately this is only one of the many challenges facing our planet. So many that we are not able to solve them one at the time, especially as solving one problem can create another one elsewhere. Fortunately we do not have to do that either as it often more cost effective to solve them simultaneously. Being a densely populated city can in this case often be a good thing.

Take for example the cleaning of waste water. In an conventional linear thinking the resulting sludge will be a problem to take care of, in a modern circular economy it will be a valuable resource: a source of clean energy and fertilizer. 

Second, no building should be demolished before the total environmental of rebuilding vs. repairing has been taken into account. Renovating instead of knocking down, supports the mission of Historic Preservation, saves natural resources and bring employment.

Third, the embodied carbon in products consumed needs to be taken into account.

These are just a few examples how to create integrate solutions, closing the loop. As a start, I suggest listing the most urgent problems to solve in Somerville, can we simultaneously take a step towards carbon neutrality?


What actions do you propose?

I suggest replacing the singular target of carbon neutrality with an broader target of resource effectivity aiming at an circular economy. Below, I provide some examples of what that could mean:


Turning waster water and other organic waste into a source of fuel and fertilizer

In an conventional linear thinking the resulting sludge from waste water cleaning will be a problem to take care of, in a modern circular economy it will be a valuable resource: a source of clean energy and fertilizer. Treating waste water as a resource instead of as an problem will bring several benefits:

1) Trough anaerobic digestion of wastewater we can produce biogas which can be be upgraded to utility gas quality replacing fossil gas used for heating.

2) Fertilizers, which after quality assurance it could in theory be used as fertilizer on farmland, but in practice the preferable use is the building of green areas. We can for example plants trees, which by binding carbon contributes to the carbon neutrality target. Furthermore, a variety of green spaces attract moisture, which is important for adaption to extreme weather events, like heavy rains and floods, which are getting more likely with climate change.

Or a soil/fertilizer for the building Roof Gardens on Public Buildings. This would also save energy by providing isolation from cold/heat: A study conducted in Chicago, USA, recently estimated that building energy savings to the value of $100,000,000 could be saved each year if all roofs were greened, as the need for air conditioning would be reduced. 

3) Less transports needed, as we do not need to transport sludge elsewhere for deposition.

bio gas bus Djurgården, SwedenAfter proper treatment the resulting biogas could also be used to run the buses on the several bus routes that run through the city. An additional bonus is that gas buses emit less noise and particulate matter than diesel buses that they could replace.

Adding an public gas tanking station would also allow converted automobiles to drive on gas.  This one at Brommaplan waste water treatment plant in Stockholm, Sweden, seems to be especially popular among taxidrivers appreciating its lower price compared to gasoline. During the last three years biogas has constantly been at least 1 SEK cheaper than gasoline per liter.

The production of biogas could be further enhanced by adding also food waste and other organic waste into the digester, simultaneously turning another waste fraction into a resource.  This should, however, not be considered as an encouragement to waste food, as the production of food creates large amount of carbon dioxide emissions itself.

"vi har dina matrester i tanken"

"vi har dina matrester i tanken" = We have your food waste in our tank. Resource collection truck in  Stockholm.

The waste water treatment plant, whether it is an conventional or one with added production of bio gas, will work better with an separate handling of excess urban runoff water. For the reminder that green areas cannot absorb, I suggest taking inspiration from Lillian Ball´s art project WATERWASH ABC, located on the edge of the Bronx River in New York City. This art project: ...engage community members to restore a wetland, clean up sediment-laden water flowing off roads, protect the shore, and teach more people about the threats of runoff to living bodies of water.


Housing stock, repairing instead of knocking down

Second example, the housing stock of Somerville is rather old, and is likely to consume more energy especially for heating. A conventional linear solution would be to knock them down, regardless of esthetic and cultural values, and replace them with modern more energy efficient building. This would, however, conflict with Somerville´s mission of Historic Preservation. From a broader perspective we need also to think about the energy embodied in building materials, how long would the energy payback time for these new buildings be? And when we add other environmental aspect, like the amount of new materials needed and waste generated, the scale is likely to tipping towards retaining the old buildings, and instead refurbish them towards modern energy standards.

Up to one fifth of the heat of the building can escape trough windows, that would be the first place to start. Replacing old ones with three-pane windows. The old windows, again can be used to build greenhouses making it possible to grow your own vegetables, for example in the many community gardens of Somerville as a part of Mayor's Urban Agriculture Initiative. Alternatively, placing them on rooftops, would both save spaces and reduce heath loss trough the roofs, which can be responsible for up to 1/4 of the total heat loss.

Consider the unemployed in the city, it is notable that repairing is often more labor intensive activity than rebuilding. Optimally, no building would be demolished before the total environmental of rebuilding vs. repairing has been taken into account. Building materials from buildings deemed for demolition should be salvaged into an building material deposit to be used into the repairing works of other buildings. 


Do not forget embodied carbon

Third, the embodied carbon, which refers to carbon dioxide emitted at all stages of a good’s manufacturing process, from the mining of raw materials through the distribution process, to the final product provided to the consumer, in the products consumed is often forgotten. The easiest way to tackle this issue is to focus on excess consumption in general. An useful tool is the "Reduce Reuse Recycle" hierarchy. The focus should be on reducing, for example by avoiding excessive packaging, and tackling the problem that is often more economic to buy new products than repairing old ones.

Reusing again is preferable over recycling because items does not need to be reprocessed before they can be used again. Local reusing centers within walking distance will make this easy. Including repairing services, will provide job opportunities. These centers could provide an cheap purchasing alternatives for people below the poverty level, but to avoid stigmatizing looking for items needed at the reusing centers should be promoted as the first option regardless of income level. The trash can should always be considered as the last resort.

To make reusing a normal and easy action, I suggest making for example the first Sunday every month a reusing day. At this day everyone can put out the things they want to sell or give away on the sidewalk or in the parks. At the end of the way the cars of the reuse center is collecting left over but useful things. This should, however, not be considered an waste disposal method.

One of these days could annually be dedicated to the collection of leftover paints. These will then be divided into two categories: light and dark colours.

The light colours will be used to paint designated dark areas, roofs etc., in light colours increasing the reflectivity of the surface and thus mitigate global warming. Researchers at Lawrence Berkeley National Laboratory found that for the northern hemisphere summer, increasing the reflectivity of roof and pavement materials in cities with a population greater than 1 million would achieve a one-time offset of 57 gigatons (1gigaton equals 1 billion metric tons) of CO2 emissions (31 Gt from roofs and 26 Gt from pavements). That's double the worldwide CO2 emissions in 2006 of 28 gigatons. Cool Roofs Can Offset Carbon Dioxide Emissions and Mitigate Global Warming (ScienceDaily July 20, 2010) The goal for Somerville should be no less than being the most reflective city in the world, showing an example for smaller and larger cities to follow. 

The dark colours can be used together with discarded old windows collected above, to build Passive Solar Water Heaters, decreasing the use of energy in heating of water.

As a goal, I would set that all roofs in the City of Somerville, would be either covered in solar heaters or cells, or plants, or painted in a light and reflective colour.

Closing the loop

These are just a few examples how to create integrated solutions, closing the loop. Could Somerville be the first circular city?

As a start, I suggest listing the most urgent problems to solve in Somerville, can we simultaneously take a step towards carbon neutrality?


Related proposals

This proposal has several connections to other proposals. (The related proposals function doesn't seem to work at the moment, you can only add one proposal).

For example those proposals in the Urban Heat Island Effect -contest that involves planting of trees and other green plants, as the anaerobic treatment of waste water will provide the fertilizers needed: ​




Who will take these actions?

Everyone. Never underestimate the power of example! 

What are the key challenges?

For the carbon neutrality goal to be workable in the long run, it must not be working against other aspects of sustainability, including social aspects. Thus a wider take on sustainability as suggested here is the only way to both achieve and uphold the target of carbon neutrality in the long run.

The total contribution towards the goal is depending on the level of commitment of the City of Somerville and its citizens. Based on the resent Q&A, the commitment is real and substantial. Thus there is no reason why the goal of carbon neutrality would not be achievable.

The potential of a circular economy as suggested in this proposal can be exemplified with a recent Swedish Case Study by the Club of Rome showing that with a combination of energy efficiency, increased amount of renewable energy and a circular economy, Sweden cut cuts its carbon emissions with almost 70 % by 2030. With a similar time frame for Somerville, there would still be 20 years left to reach 100 % cuts by 2050.

Furthermore this transformation would create create over 100 000 additional jobs to Sweden compared to business as usual. Considering the Swedish population of 9.6 million people, scaled down to the population of 77 000 in Somerville, this would mean 800 additional job opportunities, or a drop of 1 percent unit in the unemployment level of Somerville.

What are the key benefits?

  • saving money and natural resources
  • creating jobs
  • improving air and water quality
  • less transports needed
  • supporting Somerville´s mission of Historic Preservation
  • most importantly, all these measures will together contribute to a more comfortable living environment i Somerville, which again decrease the need to travel further, reducing emissions further.




What are the proposal’s costs?

Integrated actions are cost-effective. Thus the likely outcome of actions like this are cost savings compared to Business-as-usual.

Time line

Starting now, and moving forward one step at the time, it should be possible to reach carbon neutral in good time before 2050. Some intermediate goals with rewards, like an free outdoor concert halfway, and a major celebration once the target is achieved would promote that.

70 % cut by 2030 (see above) and 100 % by 2050. If not even sooner.

Related proposals

Using Biogas Technology To Improve Sanitation And Mitigate Climate Change


European Union Scoping study to identify potential circular economy actions, priority sectors, material flows and value chains

Ellen MacArthur Foundation’s Circular Economy Reports highlighting the economic rationale for the transition to a circular economy – an opportunity in excess of 1 trillion USD for the global economy.

Mrill Ingram, "Washing urban water: diplomacy in environmental art in the Bronx, New York City," Gender, Place & CultureVol. 21, Iss. 1, 2014

The Circular Economy and Benefits for Society Swedish Case Study Shows Jobs and Climate as Clear Winners