The climate emergency is a tree emergency
A tree’s root system is revealed after a wall falls away. (Photo: Tom Page via Flickr)
City councillors voted unanimously in May 2009 to recognize the climate emergency, and asked the city manager to respond appropriately.
Since then we’ve come to understand, as we didn’t at the time, that the impacts and risks of climate change are here and now, not just in other places and off in the future. This summer we’ve felt the heat and the heavy rain in Massachusetts and followed news of drought and wildfires in the West and floods in Europe and China.
You don’t need to be a scientist to sense the trend toward worse things to come. Just surviving and coping are more pressing concerns than they were a dozen years ago, what we then called “adaptation.” We wonder how people, especially the vulnerable, children and elderly, will survive the longer heat spells and hot nights, and how we can reduce the risks and extent of future floods that threaten everyone.
We have also seen in the past few years that we are rapidly losing the trees that are the most effective multifunction technology for protecting us from climate hazards.
Their shade offers shelter from hot sunlight; they pump water from the soil into the atmosphere, cooling the air in the process; and they capture heat-trapping carbon dioxide from the atmosphere and store the carbon in their wood. They even work to control flooding. If they were inventions and could be patented, they would be a huge business, and Jeff Bezos might be cavorting in tall trees instead of joy-riding in the upper atmosphere.
But as our need for them increases, Cambridge’s trees are in decline. The large old ones are succumbing to development and the effects of abuse, disease and age while too few of the new ones survive and thrive. Their decline is documented in the city’s Urban Forest Master Plan study.
Trees are our strong allies against climate change, and they need our help. Planting and caring for more trees are necessary steps, but not enough to reverse the losses.
The problem is not that we don’t want to save our trees, but that we don’t understand what they need to thrive. They are as inscrutable to us as the coronavirus we first thought was spread by contact. They are slow, silent and work in ways we can’t observe directly. And common misunderstandings about them lead us astray.
One mistaken understanding is that trees produce their invisible benefits in proportion to their diameter, that two 3-inch trees are as beneficial as one 6-inch tree. This misunderstanding is institutionalized in Cambridge’s Tree Protection Ordinance, which requires replacement trees to be of the same total diameter as trees that are removed.
When this replacement formula is used, it shortchanges us: The canopy spread and ecosystem benefits of a 6-inch tree far exceed those of two 3-inch ones. And it misleads us to undervalue the benefits of large trees, in terms of evapotranspiration, cooling, water retention and carbon capture.
Another common misunderstanding is that trees are solitary beings that grow and develop on their own, independently. In fact the new book by forest scientist Suzanne Simard, “Finding the Mother Tree,” shows that trees communicate and share resources with one another through their roots and air, that large, old trees nurture small ones, and that small ones depend on large ones to reach their potential.
This new scientific understanding implies that our policy of replacing large trees with a greater numbers of small trees is like a policy of replacing elementary school teachers who retire with greater numbers of students in the hope that they will develop into teachers.
Cambridge’s trees, our valuable allies against climate change, are in trouble, and need help urgently that only we can provide. We are trying but failing because we don’t understand them. We need to see them as a system, an interdependent community, in which the old, large trees play a critical role. And we need to value these “mother trees” much more highly than we do. We can’t replace them, and the system can break down without them.
In the spring last year, Cambridge heeded science and paused all construction projects to protect public health and keep our health care system from breaking down. Shouldn’t we be willing, now, if we understand the science, to pause and adjust construction projects at the Tobin School, Jefferson Park and the Volpe site to save mature trees to protect environmental health and keep Cambridge’s urban forest from collapsing? The trees planned for removal are irreplaceable, and we need them.
John Pitkin is a climate activist. He was a leading proponent of the City Council’s 2009 Climate Emergency resolution and organizer of the 2009 Cambridge Climate Congress.
Is anyone growing weary of the fact that “saving trees” has become the “trojan horse” for the anti-affordable housing folks, usually couched in terms of saving public health for our black and and brown neighbors. As a community we must invest in massive tree planting and tree maintenance, and we must not unnecessarily lose mature trees as a result of development. But when we see that 100% affordable housing development is being blocked by the save the trees folks who are espousing racial justice motives it becomes clear the world of Cambridge is being turned on its head.
Is anyone else weary of people who don’t know what they are talking about. Area4 if we chopped down every single tree in Cambridge, it would not produce any more affordable housing. The problem is the cost of land, not trees. We just tried to save the mature trees at Tobin, which were chopped down anyway. That’s got NOTHING to do with affordable housing, unless you were planning on living at Tobin School.
The Tobin School plan is NOT a 100% affordable housing development. It is not an affordable housing development at all. We have to stay on point with our discussions. If you have an axe to grind ( note the tree removal reference) about trees stay on subject. The loss of mature trees at Tobin was unnecessary and unfortunate. The opposition to the affordable housing overlay, the Jefferson Park development, 120 Norfolk St. etc. in order to bring climate justice to our black and brown sisters and brothers is a trojan horse anti -affordable housing strategy that I hope does not work. Be diligent, plant and maintain urban trees and insist that no trees be removed unnecessarily and fight for affordable housing citywide.
As John Pitkin points out, trees are not just wonderful because of the shade and open space that they provide us, but for their ability to fight climate change. Trees are, in reality, one of the very few weapons we have to fight climate change. Carbon sequestration is still a dream. Efforts to reduce vehicle emissions are falling behind. Home and business conversion to net zero emissions is a goal for the future, but we have a long way to go to make an impact. Trees are in reality the only significant tool we have to avoid the worst impacts of climate change.
Later this century, Cambridge will suffer tremendously due to climate change. Large portions of the city will be subject to regular flooding from storms. Most of East Cambridge and Kendall Square, portions of Cambridgeport, Riverside, Alewife, the Port, will likely become uninhabitable. Across the River, Back Bay and downtown Boston will be subject to regular flooding from our surging oceans. South Boston and just about every coastal community in Massachusetts will bear the brunt of what will soon come. The only sure option we have is to plant and maintain trees — and encourage others to plant trees. Every tree we cut down works against us.
How will your home fare in the climate crisis?
https://ss2.climatecentral.org/?fbclid=IwAR1E4s46C4Z1IRESNI1G5XsrIShiPaivWCN4cx2VRQulrtWHX_9nedbWZBA#13/42.3464/-71.0841?show=satellite&projections=0-K14_RCP85-SLR&level=6&unit=feet&pois=hide
While trees seem to be a second thought in some cases, the city of Cambridge is experimenting with temporary plastic “Whimsical shade Pavilions”, part of the Public Space Lab. These structures are a “step forward” as a place to retreat from increasing heat, meet friends, invite people to socialize. they provide additional shade in active recreational areas to reduce the impacts of extreme heat…etc. Aren’t we reinventing the function of a tree more times than not here?
how Ironic.
Also, why is everything binary as mentioned before? Either you are for us or against us? All or nothing? Incorporate trees into the design. Cull the smaller ones and save the mature ones.
This goes for affordable housing as well. Otherwise, we are just creating warehouses and heat islands for the less fortunate. The AHO is permission to strip and build without neighbor involvement or design review and will not create what has ideologically been projected.
I would be more receptive if the opinion gave a sense of understanding the tradeoffs of maintaining and extending the tree canopy. When a 2br condo costs $800k and a SFH $1.6 million, this is defacto excluding tens of thousands of potential residents who could enjoy living in Cambridge. Keeping Cambridge leafy, liberal, and loaded is another way of saying white.
Thank you John for this wonderful article.
As Christopher Stone wrote in his book, “Should Trees Have Standing?” they need to be protected just as children and animals are, because they cannot speak for themselves. Trees have a right to life and legal protection. A future without them does not exist.
Seems that the housing activists haven’t spoken with the residents of Jefferson Park and such places that will be impacted by the reduction of trees around their homes.
The Alliance of Cambridge Tenants made a request directly to the CHA for the trees and were rudely rebuffed.
Their comments were also included in the May CHA presentation when asked what they wanted to see for the Jefferson Park renovation.
They said “not too many people coming and going, open space and plenty of trees.”
Now, Kelly, isn’t it obvious that they’re a bunch of NIMBYs who don’t support affordable housing? Who do they think they are, wanting something more than a roof over their heads? Do they think they deserve what the self-proclaimed housing activists take for granted at their own homes?