Monday, March 4, 2013

The Carbon Impacts of Forest Conversion

section of forest clearcut for 16-lot subdivision in Clifton ParkA few years ago, a Planning Board Member in Clifton Park, Saratoga County posed a question I have never heard asked by anyone at the Adirondack Park Agency : how much carbon dioxide will be released by this subdivision, and what can we do about it?

As it turns out, the carbon dioxide released due to simply clearing forest land for subdivisions is eye-popping, and we know that the Adirondack Park Private Land use and Development Plan law gives the APA a lot of leverage in regulating subdivision design, lot layout and forest clearing – if they choose to use it.

One day in 2007, a typically wasteful (of land and natural resources) American subdivision was being discussed by the Clifton Park Planning Board – outside of the Adirondack Park. About ten of us in the neighborhood had gone to court to stop it on the basis that planning board had failed to take a hard look at actual and potential environmental impacts, as required by the State Environmental Quality Review Act (SEQRA). The Planning Board refused our request to declare that the potential for negative environmental impacts warranted an full environmental impact statement under the SEQRA. Therefore, there was no scope of actual or potential impacts.

For instance, the planning board had failed to take account of the function of numerous small wetlands in the woods which would be destroyed or compromised by too many single family homes, driveways and lawns. These were small vernal pools that fell outside of the DEC’s and the Army Corps’ wetlands jurisdiction, but which provided natal waters for hundreds of wood frogs and salamanders and resting places for wood ducks. All the Planning Board was willing to do was provide a 50 foot buffer around the wetlands, entirely inadequate to protect their biological functions. Also, too much fill was going to be needed to build the homes in this wet forest, resulting in the destruction of over 70% of the trees growing there, and increasing potential for flooding the basements of neighboring homes – despite the board’s stated goals of preserving much of the woods.

A Saratoga County Supreme Court judge did not agree that the town had failed to comply with the law (that’s a whole other set of problems, trying to enforce SEQRA through our court system) so we were back to the planning board trying to get as many protective conditions as possible attached to the inevitable subdivision permit.

Then, one of the planning board members raised his hand and added an impact to our list we had not thought of: What would be the carbon impact of this subdivision, he asked?

Other members of the board stared mutely ahead, since this new topic, if it was understood at all, clearly was not welcome from one of their own. “I’ve done some back of the envelope calculations,” the member continued. “I figure that 5.25 acres of the 18 might remain untouched land (I think he was optimistic), and typically in a deciduous forest like this one trees absorb 2.6 tons of carbon per acre per year, so after development that’s over 33 tons of carbon every year that won’t be taken up by this forest.”

Actually, our Planning Board member was off a bit. This forest growth in Saratoga County probably absorbs less a ton of carbon per acre per year. As Jerry Jenkins teaches us (see Jerry’s chapter Carbon Releases from Development in Science from the Field, 2000-2010 by Wildlife Conservation Society Adirondack Program), a typical hardwood forest in the northeast absorbs about 0.4 tons per acre of carbon, and since 1 ton C=3.67 tons CO2, our forest absorbs about 1.5 tons CO2 per acre per year. So, nearly 19 tons of CO2 annually will not be taken up across the 12.5 acres permanently devegetated by this subdivision.

The member’s figures might be a bit off, but his point about an important impact that nobody had raised was met with a vacant shrug. At the next meeting, the board voted unanimously (the carbon-aware member was not present) to approve the subdivision, exclaiming they had never placed so many conditions on a permit before. Because of the great recession, the subdivision has been put off for six years until this winter, when land clearing for the access road has begun. An enormous machine with a rotating head cutter has been mowing down hundreds of large oak, red maple and birch trees at a great clip right up to the 50-foot buffers or beyond, leaving us all feeling quite ill.

The carbon impacts of just clearing the land are dramatic. For illustration purposes, Jerry Jenkins assumes a typical Adirondack mixed hardwood forest holds 60 tons of carbon per acre in its above ground wood. If all that is harvested for development, Jerry assumes eight-tenths of that tonnage of carbon will be released back into the atmosphere as CO2 over the next 20 years. Converting tons of carbon to tons of CO2 (1 ton C=3.67 tons CO2) completes the calculation. So, in my example of the 12.5 acres that is now being forever converted from forest to subdivision in my neighborhood: 750 tons of C x 0.8 released into the atmosphere x 3.67 tons CO2/ton C = 2202 tons of CO2.

Jerry recommends adding 10% for the CO2 released during forest harvesting and processing later, resulting in about 2400 tons CO2 released into the atmosphere simply from clearing the land in this one subdivision. This doesn’t even account for the considerable (but difficult to calculate) CO2 losses from the below-ground, bulldozed forest soils.

Using Jerry’s methods, I calculate carbon impacts of building, heating and powering the resulting houses in the subdivision over 20 years. Jerry assumes a 4000 sq. ft. house, that the houses are heated by oil and uses grid electricity and that the average energy required is 17 kilowatt hours per square foot per year. Let’s run that calculation to heat and power the sixteen houses to be constructed in my subdivision: 17 kWh per sq.ft. x 4000 sq. ft x 16 =1,088,000 kWH x 0.7 lbs CO2/kWh = 761,600 lbs CO2 or 381 tons CO2 per year x 20 years = 7616 tons CO2 to heat and power the houses over 20 years. To actually build a 4000 sq. ft house, Jerry assumes that 65 tons of CO2 are released in manufacturing processes, while 40 tons of CO2 are stored in the house lumber, leaving a net 25 tons CO2 x 16 houses=400 tons CO2 from manufacturing/construction.

I conclude that more than one-third (35%?) of all the CO2 released from this subdivision over 20 years derives from clearing so much of the land in the first few place (I threw in 5% more due to additional loss of CO2 from the soil – it could be much more). SEQRA expects all towns and planning boards to be stewards of the air, water, land and living resources in their jurisdiction. There were plenty of reasons to downsize this subdivision, overlap its impacts through clustering of homes and avoid as much land clearing. Carbon is one of them.

Given the 150 years of statewide concern and action for the Adirondack Park, it is especially incumbent on the APA to reduce the carbon footprint of every project that comes before it, not only by assuring energy efficiency of structures that get built, but by establishing performance standards that minimize forest conversion in the first place. I conservatively estimate that the Adirondack Club and Resort, at full build out, would release well over 100,000 tons of CO2 from land clearing alone.

Photo:  A section of forest clearcut for 16-lot subdivision in Clifton Park.

Dave Gibson

Dave Gibson

Dave Gibson, who writes about issues of wilderness, wild lands, public policy, and more, has been involved in Adirondack conservation for nearly 25 years, much of that time as Executive Director of the Association for the Protection of the Adirondacks and then as first Executive Director of Protect the Adirondacks.

During Dave's tenure at the Association, the organization completed the Center for the Forest Preserve including the Adirondack Research Library at Paul Schaefer’s home. The library has the finest Adirondack collection outside the Blue Line, specializing in Adirondack conservation and recreation history.

Currently, Dave is a partner in the nonprofit organization launched in 2010, Adirondack Wild: Friends of the Forest Preserve.

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8 Responses

  1. Frank says:

    We have been building houses basically the same way for a hundred years. Track subdivisions have been popular for about sixty. I’ve been in the construction trades for 35 years and I get it. It’s the cheapest way build. But like you point out only if you are counting dollars.I am not even an engineer and I can think of dozens of ways to design subdivisions and build houses more efficiently. I also know who is on planning boards, people with special interests. Not all of course but those are the minority. I have seen builders shun towns with hardnose building inspectors and zoning boards. And I have seen towns remove those people. Don’t believe I am against building, on the contrary. I am just waiting to see when we will get it right. If you can’t get it right in the Adirondacks then the APA is a joke.

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  2. Paul says:

    The real question here on carbon sequestration is not about trying to slow or stop one subdivision through regulations or some kind of court action but about what is happening NET.

    We should try and design subdivisions in a way that will minimize the problem but the statistics we want to look at are not just the impact of the one project but what is going on park wide.

    Over the last 15 or 20 years in the Adirondacks we have put almost one million acres under conservation easement preventing any subdivisions. So all of that land will help us on net to make sure that we sequester more carbon over time.

    On the clear-cuts that have been under debate what is the data on sequestration? As these areas re-grow would they sequester more carbon over time than if the forest was managed some other way?

    Even down here in the Finger lakes with all the development we have it seems like we have more land being re-forested as agricultural land reverts to woods than we have land being cleared for subdivisions?

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  3. Pete Klein says:

    Let’s throw one more thing into the mix.
    In an odd sort of way, New York City might be the most environmental friendly development in NYS.
    How sow?
    What is lacking from the above equations is cleared and developed land per person. Houses and the lots they are on are far less efficient users of resources than are large apartment buildings. Same is true for large office buildings vs. small office buildings.
    If you took all the people living in the Adirondacks, created one city and eliminated all of the small towns and villages, you could solve all of the economic, social and educational problems in the Adirondacks – and create a larger and better wilderness.

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    • Paul says:

      No doubt about it. It would also not be much fun to live there. Pete you don’t want to move back to Detroit on the Raquette do you?

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  4. Mike says:

    It would also be useful to compare land uses. For example, is industrial forestry better or worse than uses like ACR (or other second home development) where most of the land is left undisturbed.

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  5. Mike says:

    Another interesting comparison would be industrial forest vs the Forest Preserve vs scattered second homes. How about farming?

    I’m not sure about the answers, but it does raise interesting questions

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  6. TiSentinel65 says:

    Dave, you raise an issue most people look past, however the laws of supply and demand are at work here. If you build it they will come. I see many houses that to me are just huge in scale and I always wonder about heating costs associated with such structures. If people could be shown the advantages towards better efficiency and the benefits of smaller scale, the appeal may get more people to buy into it. People seem to forget the costs associated with heating such buildings, and it can be substantial. Certainly keeping the heat inside where you want it could also reduce the burning of fossil fuels. My next house will definitely be smaller and easier to heat BTU wise.

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  7. Dave Gibson Dave Gibson says:

    I appreciate the perspectives offered to my post, and the excellent questions. Practicing “carbon forestry” on some private forests – through longer rotations which sequester and store carbon – certainly helps where it also meets the expectations of the landowner. I apperciate why this can’t be easily done on large commercial timber investment operations. I doubt that the type of high grading forestry practiced by Oval Wood Dish Liquidating Industries would have the permanent carbon impacts of the ACR subdivision over 20 years of the development. But over the course of 80-100 years? Who knows. Good question. As is Paul’s emphasis on net results of practicing forestry with nearly a million acres under easement vs. the relatively smaller acreage under subdivided development. Frank and Ti, your perspectives too are most valuable.

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