There are dire predictions for oncoming hot days, but solutions are complex and look to residents
Kids play in the cooling fountain at Harvard’s Science Center Plaza in Cambridge. (Photo: Kate Wheatley)
Cambridge is facing much higher temperatures, with predictions that the number of days above 90 degrees could almost triple by 2030 and might be the norm every day of summer by 2070. Yet the city’s ambitious plan to deal with climate change shows that protecting residents, businesses and infrastructure from excessive heat is more complicated than preventing harm from flooding and storms. And oppressive heat could be more dangerous than floods: It causes more deaths than any other element of natural disasters.
“As a city we have experienced flooding for a long, long time. There’s a mature program in place in terms of mitigating flooding,” assistant city manager and former public works commissioner Owen O’Riordan said in a telephone interview Sept. 20. “When it comes to excessive heat, Cambridge is in a different place than the tropics.” In other words, the city, like other communities in the Northeast, isn’t used to coping with steamy tropical weather.
The predictions are dire. By 2030, increased temperatures could affect Cambridge police headquarters, the city’s emergency communications center, the ambulance service ProEMS, the public health department’s main office and several schools and low-income housing developments, according to projections in the city’s Climate Change Vulnerability Assessment prepared in 2015.
“Cascading effects” from a heat-caused loss of power could be devastating, affecting “the availability of air conditioning, drinking water, lighting, refrigeration, communications and other systems that require power,” the report says.
Regularly 115 degrees by 2070
A graphic from Cambridge’s Climate Change Vulnerability Assessment gives a sense of the city’s impending heat concerns.
Most vulnerable to extreme heat are “people living below the poverty level, young children and elderly adults living alone,” the assessment said. Mapping those populations identified certain areas of North Cambridge, The Port and Riverside as most at risk. Besides that, maps show local “urban heat islands” within the city that face higher temperatures because of factors such as lack of tree cover, more impervious and heat-absorbing surfaces and older housing without adequate ventilation and air conditioning. The average heat index in those areas – in East Cambridge, North Cambridge, Central Square, Cambridgeport and MIT/Area II – could reach 100 degrees when the average in the city is 96 degrees in 2030; and could exceed 120 degrees when the city average is 115 degrees in 2070.
An effort by the city’s Community Development Department and units of the National Aeronautical and Space Agency and the American Geophysical Union, which included measuring roof reflectivity from above, produced the Cambridge Urban Heat Dashboard. It shows roof “albedo” – a number representing how well building roofs reflect sunlight, thus reducing building and area temperatures.
The dashboard reports albedo for virtually every roof in the city in 2008, 2013 and 2018. It lets users look up roof albedo at any address, and also shows neighborhood albedo levels and changes in albedo over those years. Roof reflectivity has increased during that period, mostly from nonresidential buildings. Another section of the dashboard shows the difference between ambient temperatures in the suburbs of Eastern Massachusetts and temperatures in the “urban heat islands” of Cambridge and other cities.
Getting communities to take lead
The plan for dealing with excessive heat is considerably less explicit. As outlined in Resilient Cambridge, the city’s climate change blueprint, it relies heavily on self-help by residents and actions by the private sector rather than government assistance. It calls for strategies to develop “closer communities” so that “members of the community look out for each other,” O’Riordan said. Along the same lines, the city wants to “enable people to think about what they can do to help themselves,” he said.
As an example of city efforts to foster closer ties among neighbors, O’Riordan cited the city’s invitation over the summer encouraging citizens to hold block parties, offering $200, permits and play equipment for kids. “It encourages a stronger network,” O’Riordan said. Cambridge also wants to develop “neighborhood hubs” as places to come for information and support around climate change, including high temperatures. So far it is applying for funding for one site, the Cambridge Community Center in Riverside.
Another goal is developing a “leader program identifying people who can advocate for more education around climate change,” O’Riordan said.
More trees and more roofs with high albedo could reduce temperatures, according to research. Cambridge’s Urban Forest Master Plan calls for every neighborhood to have at least 25 percent tree canopy coverage. As of 2020, when the plan was published, six neighborhoods fell below that figure: East Cambridge, MIT/Area II, Wellington-Harrington, The Port, Cambridgeport and Riverside. City spokesperson Jeremy Warnick said the city will plant at least 1,000 street trees a year in furtherance of the pledge to have 25 percent canopy coverage in each neighborhood; critics have said neglect of street trees has led to trees dying.
Miyawaki forests
The Miyawaki forest at Danehy Park in North Cambridge after two years. Photo: Biodiversity for a Livable Climate)
Recently Cambridge announced opening a park in East Cambridge with a micro-forest of almost 400 trees on less than an acre. Volunteers, aided by the city, have planted two similar tree projects, known as Miyawaki forests, in Danehy Park in North Cambridge and Green-Rose Park in The Port. Miyawaki forests, named for the Japanese botanist and plant ecologist who developed the idea, are thickly planted collections of diverse trees that grow fast, restore natural habitat and provide cooling and shade.
The urban forest plan also enlists several city agencies to help increase and preserve the city’s tree canopy, which has been shrinking. But according to the plan, the majority of trees now standing in the city – and most of those that are removed – are on private property. And for the most part, the Resilient Cambridge answer to excessive heat from climate change calls for private citizens and developers to increase the tree cover and lighten roofs and pavements. The city is nudging builders to act with new zoning rules that require large projects and substantial renovations to meet “green factor” standards that include preserving and adding trees, building vegetation-covered “green roofs” and adding canopies and other shade elements. Each project must achieve a certain “cool score” – a number made up of the development’s performance in the “cool factor” strategies – to win city approval.
The heat-related zoning requirements became effective May 23; Warnick said that so far seven projects have won Green Factor certification at the building permit or special permit and design review stages. The zoning rule mandates a separate review and certification at each stage of the approval process: before builders get a special permit, building permit and certificate of occupancy.
This is all peanuts relative to removing as much asphalt as possible from the city.
How to persuade the city and the developers that that tall buildings they’re planning are detrimental to a cooler city and a public health issue? Housing can and should be built with mid-rise, gentle density principles, allowing for as many units as the city’s infrastructure will allow.
Thank you!
Federico Muchnik
Candidate for City Council
federicoforcouncil.net
Increased building heights and more concrete will worsen the situation from heat if the city building height and expansive development plans go thru.
Additionally our ever shrinking greenspace situation also will add to the affects of heat increase.
Depending on residents and developers to somehow reduce the effects, while the city tries to convert us over to an all electric heat/ac system will prove insufficient and potentially disastrous.
Our current council is not looking at the big picture and such issues. We need more than storm/flood control, though that is definitely an issue (and why are we not putting a flooding barrier along the river that would help deal with more immediate flooding issues along memorial drive etc?)
Additionally we need a commitment by the utility companies in regards to their underground cabling and power systems to include detection and suppression of dangerous gas, smoke and fire problems where they have such in the city. Recent exploding manholes and fires have show that they have done little since the last time this happened a few years ago and could easily endanger the public as well as the utilities in the city. If this is not something the city itself can force upon them than we need our state representatives to take it up in the legislature so that something could be required statewide as we are not the only city to have such risks or to have had such incidents in Massachusetts.
People living in urban areas have a dramatically lower carbon footprint than those living in suburban or rural areas: https://www.nytimes.com/interactive/2022/12/13/climate/climate-footprint-map-neighborhood.html
Building density where there is transit, services, and employment reduces peoples need to drive, and at very least the distances they drive. Urban housing also has lower heating and cooling costs due to shared walls, floors, and ceilings: https://www.epa.gov/sites/default/files/2014-03/documents/location_efficiency_btu.pdf
Urban areas also increase the efficiency of distribution of all kinds of resources by reducing the distances necessary to transport them: https://www.eea.europa.eu/highlights/resource-efficient-cities-vital-step
There is incredible demand for housing in the Boston area. Either we build it where it makes sense (areas of existing density, proximate to transit and services) or it will continue to be built ever further outwards, increasing energy usage, car dependency, and eliminating ever more green space. Unfortunately the latter is the ongoing trend and there is absolutely no environmental justification for maintaining it: https://www.newgeography.com/content/007430-all-major-metropolitan-area-growth-outside-urban-core-latest-year
Slaw – again this does not address the materials problem. Concrete holds heat and makes hot weather worse, not better.
Yes, if people work where they live they need less use of carbon emitting vehicles, but that requires a public transit system that is reliable and more extensive than what we have in this state. We can’t even get the MBTA to fix ongoing safety issues, and its own carbon footprint issues and things like access for folks with mobility issues. Cambridge cannot solve these issues alone, it needs the state government on board to do something to deal with such.
You seem to be singing the megacity urbanist pipe dream song that I have seen way too many times on Youtube ect. and which fails to deal with the reality that people are people and our city has a constantly rotating population.
That’s also the problem with “neighborhood block parties etc.” to rebuild connectedness. I have very few neighbors that have been here for even a few years, most of the buildings in Riverside are constantly changing residents. I have enough trouble getting folks to compost with the city program or other simple programs as they are here one year and gone the next.
“Concrete holds heat and makes hot weather worse, not better.”
Yes it does. Good thing concrete is not the only building material. Take for example: https://www.bostonplans.org/planning/planning-initiatives/boston-mass-timber-accelerator
Again though the options are functionally up or out and building outwards actually uses a lot more concrete and asphalt than building up because it requires more roads etc. while eliminating more green space. Climate is a global system and you cannot only focus such local impacts. If urban areas refuse to house the people who want to live in them that has tremendous environmental consequences. There are so many better ways to mitigate urban heat island effect than attempting to prevent density in urban areas, which as I showed has a lot of environmental benefits.
“Yes, if people work where they live they need less use of carbon emitting vehicles, but that requires a public transit system that is reliable and more extensive than what we have in this state. We can’t even get the MBTA to fix ongoing safety issues, and its own carbon footprint issues and things like access for folks with mobility issues.”
So what is your actual alternative? low density sprawl doesn’t suddenly become more environmentally friendly because the T is struggling right now. The safety and reliability issues at the T are temporary. Making long term development plans around that makes no sense at all. Dense walkable communities are better for the environment even without functional transit, while also providing a natural constituency to demand transit improvements. Sprawl only begets car dependency creating a vicious cycle of more sprawl and car dependency.
The carbon footprint of mass transit is a complete red herring. Public transit even powered by fossil fuels is so much more efficient than SOVs per passenger it’s not even close: https://afdc.energy.gov/conserve/public_transportation.html The T has plans for electrification which will only reduce that even further.
The T is also miles ahead of its peer systems of similar ages (even including in Europe) in terms of accessibility and it continues to get better in that regard every year. See: https://www.mbta.com/projects/accessibility-improvements Chicago, New York, Philly have much less accessible public transit than Boston. It obviously must be better but this is not an argument against the relationship between urbanism and sustainability. Again It is just a red herring.
“You seem to be singing the megacity urbanist pipe dream song that I have seen way too many times on Youtube ect. and which fails to deal with the reality that people are people and our city has a constantly rotating population.”
This doesn’t make any sense, density =/= megacity and Cambridge is not at any risk of becoming one anytime soon. And of course people rotate through cities that is part of being a city (but more people might be able to stay if Cambridge actually had enough affordable housing for all the people who want to live here). This has nothing at all to do with the arguments I made though, which are all well sourced and you did nothing to refute. Yet another red herring.
Slaw
The MBTA has been struggling in one form or another my entire 6 decades living in the Boston Area. “Temporary” is hardly an appropriate term.
The heat maps you are pointing at are nowhere near up to date, and things change here constantly. Numerous buildings have come and gone, businesses come and gone and residents come and gone since 2018.
And the technology has moved on that was used to produce said maps, which is good because they are clumsy to use by someone who isn’t an expert in such things. And what they show is not well documented as to what it means (or even when the data was taken from in regards to time period, or even season).
Transportation is about 25% of the Boston Area Carbon footprint according to reports I have seen. And a chunk of that is our ancient public transit system.
Usage level of the MBTA by ridership is still down 40% from 2019 levels according to reports in the press. People don’t trust it. It lurches from one problem to another. The state legislature neglected it and burdened it for years so it remains filled with safety issues and hampered by vehicle breakdowns etc from bad maintenance and old equipment.
I have mobility issues, I have not used the subway system itself in 4 years, guess why? Because of its access problem. You can site studies etc or you can learn from the direct personal experiences of people with mobility issues in dealing with the MBTA. There are plenty of folks who can give you insight in regards to elevators that don’t work, or which are not cleaned (and smell like a badly maintained toilet) etc. and escalators that spend at times YEARS being out of order at some stations (for those of us who are not in a wheelchair but totter around on canes).
It’s been 34 years since the ADA was passed. High time government facilities and public transit was compliant. That’s half a lifetime for some folks.
Are you native to Cambridge? Do you live here? How many decades have you lived here? Or in the state? Do you own a car? Do you use public transit?
I’ve been here as a resident for 25 years. I’ve lived in the state for almost all my life except for a few months when I was a child.
Our city is the 25th most densely populated one in the country, right behind San Francisco according to the 2020 census. (Also 4th largest in the state of MA at that time). Since our population is still rising that makes me think we do have to worry about size.
Wikipedia has a copy of the data for quick access (comes from the US Census Bureau):
https://en.wikipedia.org/wiki/List_of_United_States_cities_by_population_density
Since the main point of the article is that we are a giant heat bubble in the state, you’re arguing counter to solving the problem by arguing that having people live elsewhere creates a bigger carbon problem in the long run.
I think we need more discussion of finding solutions that can reduce temperatures rather than pie in the sky arguments about what can only be addressed on a state or national level.
Yes, going to Wood and other lower heat holding materials would be fantastic (I live in a wooden building built more than 100 years ago so I understand the benefits of such compared to folks living in concrete and glass structures).
Is this in any of the increased height overlay rules and zoning rules that are being forced on the property owners who are building new structures?
I think we might want to consider “radical” concepts, like those being used in Phoenix AZ where they have a treatment for the city streets and roads over existing materials that turns it in to a surface that does nor retain heat as much as when it is left in the form we have here in Cambridge. Applying such a surface cover could reduce heat in the city during the hot summer months and is one the City Council and the City Manager could look into the data on and see if it is financially possible for us.
Local doable solutions are what we have to do here. You talk about global solutions, but we’re one city in one state in one country. We have to deal with the now… as in next summer or the one after that and how things impact us. We should not be building to add another 10k people into our already dense city to somehow protect the rest of the state from sprawl.
“Transportation is about 25% of the Boston Area Carbon footprint according to reports I have seen. And a chunk of that is our ancient public transit system.”
The percentage is negligible and declining. This is a foolish argument it is incredible to me you are doubling down on it.
“ Usage level of the MBTA by ridership is still down 40% from 2019 levels according to reports in the press.”
Talk about out of date information… the actual number is over 60% and it’s higher on both commuter rail and busses https://recovery.transitmatters.org/
“ It’s been 34 years since the ADA was passed. High time government facilities and public transit was compliant. That’s half a lifetime for some folks.”
I agree with you here. Again though this has nothing to do with arguing against density.
“Are you native to Cambridge? Do you live here? How many decades have you lived here? Or in the state? Do you own a car? Do you use public transit?”
Boston, yes, my entire life, do not own a car, I rely on walking, biking, and the T.
“ Our city is the 25th most densely populated one in the country, right behind San Francisco according to the 2020 census. (Also 4th largest in the state of MA at that time). Since our population is still rising that makes me think we do have to worry about size.”
Only if you presuppose density itself as a problem which it isn’t for all the reasons I have shown. Density is good.
“ Since the main point of the article is that we are a giant heat bubble in the state, you’re arguing counter to solving the problem by arguing that having people live elsewhere creates a bigger carbon problem in the long run.”
Nope let me repeat what I actually said: There are so many better ways to mitigate urban heat island effect than attempting to prevent density in urban areas, which as I showed has a lot of environmental benefits.
Cooling Cambridge at the expense of the world is not a noble goal.
“ I think we need more discussion of finding solutions that can reduce temperatures rather than pie in the sky arguments about what can only be addressed on a state or national level.”
Im not talking about anything on the state or national level I am saying that Cambridge increasing to densify is a net positive for the environment. I’ve provided a lot of evidence to back that up too and you haven’t actually refuted any of it.
“ Is this in any of the increased height overlay rules and zoning rules that are being forced on the property owners who are building new structures?”
Not yet but it would be better to argue it should be than to argue against density.
“ I think we might want to consider “radical” concepts, like those being used in Phoenix AZ where they have a treatment for the city streets and roads over existing materials that turns it in to a surface that does nor retain heat as much as when it is left in the form we have here in Cambridge”
this is a good idea again a better thing to argue for than against density.
“ Local doable solutions are what we have to do here. You talk about global solutions, but we’re one city in one state in one country. ”
Im actually not though I am saying the decisions we make here have broader impacts. Namely if Cambridge refuses to house the people who want to live here they are likely to go to the suburbs and exurbs, expanding low density sprawl which is far worse for the environment. Local decisions have global consequences, that’s my point.
“ We should not be building to add another 10k people into our already dense city to somehow protect the rest of the state from sprawl.”
Yes absolutely we should. We have transit, we have good pedestrian and biking infrastructure, we have good social services, decent schools, etc etc. we should be making it possible for more people to live here so they don’t instead live in far more environmentally damaging locations.
Why is the city paving another street or laying another sidewalk that is not permeable? planting a single tree (not 3 or 4) when every planting is done?
Is every city building being assessed for a climate friendly roof, open space, trees and plants as well as benches, permeable parking lots or play lots, etc.? Then retrofitted.