ULTRA-Ex Boston

Providing the basis for action to reduce Boston's carbon footprint

  • This project aims to periodically account for all significant carbon sources and sinks attributable to the city of Boston.
  • This project integrates diverse tools including satellite remote sensing, meteorology, tree physiology, socioeconomic analysis, and interdisciplinary public policy, to address a problem in Boston, its greater region, and human communities everywhere.
  • Most importantly, this project seeks community ideas and input, to inform the most effective use of these powerful research tools, and ultimately make Boston a more sustainable city.

How do humans and their environments interact to produce geospatially and temporally varied CO2 exchange in a metropolitan region?

Boston ULTRA-EX is an interdisiplinary examination of ‘Urban Carbon Metabolism’ across a rural to urban gradient from Harvard Forest Long-term Ecological Research site (HF-LTER) to Boston. Using a ‘Coupled Human-Natural’ framework, this study will implement measurements of the biophysical environment (remote sensing, atmosphere-biosphere interactions, plant physiology, carbon cycle processes) coupled with data on the human/built environment (energy use, transportation, GIS data, economic activity) to quantify carbon exchanges and dynamics at high temporal and spatial resolutions. This research is the first of its kind; linking and quantifying the physical, climatic, ecological, and anthropogenic drivers of carbon emissions, concentrations, and fluxes.

Natural Drivers of Carbon Exchange

Natural mechanisms driving carbon exchange will be investigated through new urban-ecological studies and by leveraging existing projects at Harvard Forest. Remote sensing and field-based observations will characterize changes in ecosystem structure and function across the Boston urban to rural gradient. Net marine/aquatic carbon exchange will be investigated through spot sampling, chlorophyll studies, and coastal modeling.

Anthropogenic drivers of carbon emission and exchange

Energy use is a key driver of urban metabolism and an important source of carbon emissions. Using geographic information systems we will combine spatially explicit data on energy use, transportation, and demographics to model atmospheric transport of CO2 across the urban-to-rural gradient. In addition, econometric techniques will be used to quantify and model the demographic, socioeconomic, behavioral, and institutional drivers of energy demand and their relationships to carbon emissions.

Atmospheric Integration of Coupled Human-Natural Carbon Exchange

Using state-of-the-art instrumentation we are able to measure atmospheric CO2 concentrations with tremendous precision and accuracy. Our measurement strategy is based on long-term observations of CO2 concentrations upstream and within the urban core, using sites at Boston University (BU), Harvard Forest LTER, and a new site in Worcester (installed winter 2011). The data will be supplemented by short-term flux tower deployments along the gradient and CO2 measurements from aircraft. New Picarro δ13C/CO2/H2O monitoring instruments from the USFS have been tested at BU and will be deployed periodically during the campaigns. Data from these instruments will be assimilated into models allowing us to quantify and visualize sources and sinks of CO2 at high spatial and temporal resolutions.

Elements in Progress for 2011 and beyond

  • Urban CH4 source/sink characterization
  • Electricity and fuel oil emissions and sensitivity
  • VPRM model extension to full region (quickbird, MODIS, Landsat fusion)
  • Transportation modeling
  • Future land use scenario assessment
  • Urban food assessment (agricultural land rent, transportation, security, etc)
  • Urban-to-rural gradient and trajectory assessment
  • Ocean and river carbon transport dynamics
  • Tree ring studies of urban invasive species
  • And much, much more


March 9, 2011 Terrestrial to marine carbon flux in the Boston ULTRA-Ex region
This Poster describes efforts to model carbon fluxes from land to the sea. It was presented at NASA's North American Carbon Program meeting in New Orleans (Jan 31 - Feb 4, 2011). Click Here for Large Version


March 2, 2011 Successful CO2 profile experiment
We have just completed 48 hrs of measurements that suggests a strong gradient in atmospheric CO2 concentration with altitude (up to 30 meters above street level) during the daytime hours. This concentration gradient largely disappears at night. We have only begun to explore these patterns and will combine our preliminary results with atmospheric data to determine how wind velocity, turbulence, and emissions from cars and buildings influence CO2 concentrations in space and time. Our thanks to the folks at Picarro for loaning us the equipment for this study. Some preliminary data:


August 30, 2010 First season of field research winds down
Many projects have begun across the Boston MSA (Metropolitan Statistical Area) and beyond. This map shows two transects radiating from Boston. The green markers show locations where we have measured carbon in soils and vegetation. We'd like to thank to all of the residents and businesses who allowed us to visit their properties to conduct this research.


April 1, 2010 New Postdoc Joins ULTRA
Steve Raciti joins the team as a Postdoctoral Research Associate. He recently completed his PhD from Cornell University, where he studied urban ecosystems. You will find a link to his website here: http://people.bu.edu/raciti/

March 9, 2010 Successful mobile CO2 measurement campaign
We've been measuring CO2 concentrations across the region using a Picarro CO2/CH4/H2O Analyzer. Preliminary measurements highlight the spatial variability of gas concentrations and the importance of urban point sources.


Aug 20, 2009: ULTRA-Ex proposal
Below (click on "files" at the bottom of this page) is a pdf of our recent proposal to the National Science Foundation to conduct a study of Urban Metabolism in the Boston Metropolitan Region.

July 15, 2009: 3D Lidar Video
This animation is a 3-dimensional rendering of our "Greening Back Bay" neighborhood test bed, for which we are aiming to do carbon exchange modeling described below

June 30, 2009: Back Bay Carbon Footprint
Below are two clips that together illustrate a powerful new approach to measurement of urban carbon stocks and flows.

The first clip below shows a dawn-to-dusk solar progression for a clear-sky, idealized June 19, over our "Greening Back Bay" neighborhood test bed. The blue text shows the Prudential and Hancock Buildings. This clip indicates our approach to real time carbon exchange modeling, at unprecedented temporal and spatial resolution. The data used in this clip extends to the entire I-95 beltway and beyond. This video was made by Jared Newell with help from Nik Medrano, and is based on Quickbird 2.4 m imagery (from which vegetation 'greenness' is computed) overlain on 1 m LIDAR elevation data. Soon we will have estimates of the diurnal carbon exchange from buildings and vegetation, using the Vegetation Photosynthesis and Respiration (VPRM) model developed by our collaborators at Harvard University, and validated with ground based measurements. Stay tuned!

The second clip below is from the "Echinda" ground based LIDAR, developed by colleagues in Australia and under intensive testing in the field by Boston University researchers. The clip is from a real forest plot at Sequoia National Park. This ground-based system can resolve the 3-dimensional volume of trees, allowing us to go far beyond current approaches to estimating the carbon biomass of trees, which rely on coarse mathematical equations based on tree diameter and height. Combined with the approach in the first clip, we have the capacity to measure urban carbon stocks and fluxes with unprecedented precision and accuracy.
- Posted by Nathan Phillips, June 30, 2009

June 30, 2009: Echidna

High Definition Echidna

To read more about the Echidna, go to http://www.bu.edu/remotesensing/lidar/

June 30, 2009: Google Earth Map of Trees of the Greening Back Bay Project
Click on the following link to view a KMZ file of a Google Earth Map detailing the locations and species of trees in the two-block "Greening Back Bay" test site initiated by Boston City Councilor Mike Ross. After clicking on the KMZ attachment, click on the placemarks to view both specie and a link to a website that goes into further detail about each specific tree. Click on the picture to view the image without opening Google Earth.


-Posted by Nik Medrano, June 30, 2009

June 30, 2009: Project Vulcan
Our student intern Nik Medrano just posted a nice video from Kevin Gurney's awesome Project Vulcan at
- Posted by Nathan Phillips, July 1, 2009

Apr 21, 2009: Red Sox Carbon Offset Project
This project was done last spring at Colby. I figured it was a pretty cool way of looking at carbon emissions/offsets. The ideas presented in here could be a great way to teach the public more about carbon emission and offsetting them. The authors of this study make great points to the power of Red Sox baseball and how they can be used to influence their fans! http://www.colby.edu/environ/courses/ES212/aom08/projects_pdf/es21208_redsox.pdf
- Posted by Tom Nickerson, April 21, 2009

Mar 18, 2009: E.P.A. Announcing Potential Mandate for Recording Industrial Carbon Emissions
The EPA is floating the idea to enact policy to require industrial companies to record and publish their emission records. A great step in the direction for future Cap and Trade policies! http://www.nytimes.com/2009/03/11/washington/11epa.html?_r=1&ref=earth
- Posted by Tom Nickerson, March 18, 2009

Mar 18, 2009: A Carbon Diet? Possibly in the Future.
An interesting article in todays Boston Globe. This article focuses on the carbon footprint of consumer products, particularly food and beverages. Perhaps one day we will look at the carbon footprint of food just as we do calories today. [http://www.boston.com/lifestyle/green/articles/2009/03/18/en_route_to_greener_life_youll_need_a_map/?page=2]
-posted by Zack Tyler, March 18, 2009

Mar 16, 2009: NY Times Carbon Graphic
This was posted in the NY Times, showing the emissions breakdown by sector. Pretty basic but still cool. http://www.nytimes.com/interactive/2008/05/30/business/20080601_ENERGY_GRAPHIC.html?ref=earth
- posted by Tom Nickerson

Mar 6, 2009: California Carbon Control
From today's LA Times: "State's proposed emissions rule sparks firestorm
The new standard would gauge a fuel's 'carbon intensity,' from its source to its burning.
California regulators Thursday issued a far-reaching proposal to slash carbon emissions from transportation fuels, setting the stage for a national battle over how to reduce the damage to the global climate from gasoline and diesel combustion.
The low-carbon fuel standard, if approved next month by the state's Air Resources Board, would be the first in the nation to restrict greenhouse gases produced by a fuel, from its source to its burning."
- posted by Nathan Phillips

Mar 5, 2009: Channeling an inconvenient rule through carbon
Here at bostoncarbon.org one of us was just told that we must hand sign a document and send it by snail mail to Australia. The time is long past due for widespread acceptance of electronic or scanned signatures, based on efficiency, convenience, and environmental sustainability. Moreover there is no demonstrable benefit of ink signatures as a guarantee of authenticity. Speaking up about outdated policies, however small, is civic duty - otherwise we may be in this same position decades from now. We have asked for a change in policy, but as this is a large government organization, we are not expecting quick change. However, this blog will be an occasional chronicle of an attempt to change a small policy, enjoying some potential absurdities along the way, and ultimately helping to reduce carbon emissions through unnecessary snail mail postings (http://standardcarbon.com/resources/?p=20).
- posted by Nathan Phillips

Mar 2, 2009: Logan Airport Carbon Fee proposed
From today's Boston Globe:
"In the same month that Logan International Airport hiked its parking rates by $1, Governor Deval Patrick is asking for another $2 parking "carbon fee" as part of his transportation overhaul filed this week." Here's the full article:
- posted by Nathan Phillips

Feb 24, 2009: Obama Speech to Congress carbon reference
"I ask this Congress to send me legislation that places a market-based cap on carbon pollution and drives the production of more renewable energy in America."
- posted by Nathan Phillips, February 24, 2009

Feb 21, 2009: Thoughts on the nuts and bolts of direct measurement of urban CO2 "metabolism"
(Below is an edited email excerpt from colleague Mark Potosnak of DePaul University):
I'm attaching a really good paper on urban co2 fluxes. (Vesala T., et al. 2008. "Surface–atmosphere interactions over complex urban terrain in Helsinki, Finland" Tellus 60B:188–199) Here are some points: First, Figures … basically say that the urban data behaves the same as tower data over a forest. The neat thing they do is run a complex model to calculate the tower footprint. Finally, I like that they correlate measured co2 fluxes with traffic density. With the tolls, we should be able to get this for the Mass Pike. And I would hope there's info for Storrow drive, too.
- posted on behalf of Mark Potosnak by Nathan Phillips, February 21, 2009

Feb 7, 2009: Do-it-Yourself Home Carbon Footprint Analysis
\Here is a site that allows you to input the specs of your home, and in turn you receive a rough carbon footprint analysis of your house. This can be useful for aggregating residential data on a small scale. For instance, if you live in a neighborhood where all the residential units are similar in size. From there you could make some general assumptions, such as every home uses heating oil, and every home was built around the same time period. I think this can be a useful tool in getting a rough estimate of each of our carbon footprints at home. Note, this is exactly that, a rough estimate, but it at least gets us thinking about what we can do differently, and gives us some sort of baseline for a particular type of residential unit. The program was developed by Lawrence Berkeley Laboratory's, and is called the Home Energy Saver. The link is http://hes.lbl.gov/.
-posted by Zack Tyler 2/7/09

Dec 8, 2008: Long term socio-ecological research - a paradigm for Boston's carbon footprint analysis?
My colleague Ian Sue Wing at BU forwarded me an interesting link that tweaks an ecological research concept (Long Term Ecological Research, or LTER) to make it more relevant to carbon footprint analyses in the built environments where most people work and live. Basically it makes a forest ecologist like myself think about how my research relates to the parks, open spaces etc. in a place like Boston, and how this ultimately integrates with the carbon emissions caused by human activity. The US National Science Foundation has recognized the concept of urban ecosystems by establishing a couple LTER sites in Baltimore and Pheonix, but this LSTER concept paper takes it a step further. Take a look at: http://www.ecologyandsociety.org/vol11/iss2/art13/ES-2006-1786.pdf
- posted by Nathan Phillips, December 8, 2008

Dec 7, 2008: A direct measurement of Boston's Carbon Footprint
One of the most integrated estimates of the carbon footprint of an area like greater Boston comes from measuring it directly. And we have tools to do this. Ecologists do this all the time in natural ecosystems with a technique called "eddy covariance", which is a glorified weather station perched on a tower above a forest, grassland, crop, etc. This gear measures each and every puff of wind going into our out of the ecosystem, and how much carbon is carried along with those puffs. At the end of an hour, day, or year, we know how much net carbon dioxide was emitted or absorbed by an area under the tower. This integrates all of human activity leading to carbon dioxide emissions as well as the uptake of carbon dioxide by all the trees, parks, and open spaces in greater Boston. Boston University has a system on the roof of our building, and you can take a look at the data at Prof. Mark Potosnak's website at DePaul University: http://condor.depaul.edu/~mpotosna/
- posted by Nathan Phillips, December 7, 2008

Dec 8, 2008: Bostoncarbon.org under construction
I am starting this site off as a blog, with plans to wikify it and allow it to grow as a community effort. So please be patient as the functionality comes on line!
- posted by Nathan Phillips, December 8, 2008

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