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Fabricating “facts” to support native plant restorations.

October 3, 2011

We have been debating with native plant advocates for a long time, so we’re never surprised when they repeat vague generalities to support their ideology.  But when these fabricated “facts” are repeated in legal documents such as the Draft Environmental Impact Report (EIR) for the Natural Areas Program (NAP) we must admit that we’re shocked!  Apparently, the highly paid professionals who write such documents don’t expect the public to actually read the references they cite to support the statements they fabricate.  We will take our readers on a tour of some of the phony “science” used to defend the destruction of San Francisco’s urban forest in order to restore native grassland and scrub to San Francisco’s urban parks.

Why is carbon storage such an issue in this debate about the Natural Areas Program?

The urban forest of San Francisco stores 196,000 tons of carbon and adds to that accumulated store of carbon at an annual rate of 5,200 tons per year according to the US Forest Service survey.  About 25% of the annual rate of sequestration and the accumulated storage of carbon are accomplished by the blue gum eucalyptus, the chief target for destruction by NAP’s plans.  When a tree is destroyed, it releases the carbon that has accumulated throughout its lifetime into the atmosphere as Carbon Dioxide as it decays.  Carbon Dioxide is the predominant greenhouse gas that is causing climate change. 

Carbon storage by tree species, San Francisco. US Forest Service

Since greenhouse gases are regulated in California by a law that commits the state to reduce greenhouse gas emissions, the Environmental Impact Report (EIR) for the Natural Areas Program (NAP) goes to great lengths to make the case that destroying thousands of trees will not violate California law.  Here are just a few of the “facts” fabricated by the EIR to convince the public that NAP’s plans to convert San Francisco’s urban forest into grassland and scrub will not harm the environment.   

Grassland in the San Francisco Bay Area does NOT lower ground temperature

The EIR claims:

“According to a study presented at the American Geophysical Union’s meeting, grasslands above 50 degrees latitude reflect more sun than forest canopies, thereby keeping temperatures lower by an average of 0.8 degree Celsuis.” ( EIR, page 457, cited source(1))

This statement in the EIR does not apply to the San Francisco Bay Area and the reference used to support it misrepresents the cited study:

  • The entire continental United States, including the San Francisco Bay Area, is below 50 degrees latitude.  In other words, this statement—even if it were true—does not apply to the San Francisco Bay Area.
  • The statement is taken out of the context of the article.  The entire sentence in which this statement appears actually says, “Grassland or snowfields, however, reflected more sun, keeping temperatures lower.  Planting trees above 50 degrees latitude, such as in Siberia, could cover tundras normally blanketed in heat-reflecting snow.”  It does not snow in the San Francisco Bay Area.  Therefore, this statement does not apply to the San Francisco Bay Area.
  • The article being quoted by the EIR is NOT the scientific study, but rather a journalistic article in The Guardian, a newspaper in England, in which the author of the study has been misquoted and his study misrepresented.
  • The day after this article appeared in The Guardian (and also in the New York Times), The Guardian published an op-ed (which also appeared in the New York Times) by the author of the scientific study, Ken Caldeira  in which he objected to the misrepresentation of his study:

“I was aghast to see our study reported under the headline “Planting trees to save planet is pointless, say ecologists.” (December 15).  Indeed, our study found that preserving and restoring tropical forests is doubly important, as they cool the earth both by removing the greenhouse gas carbon dioxide from the atmosphere and by helping produce cooling clouds.  We did find that preserving and restoring forests outside the tropics does little or nothing to help slow climate change, but nevertheless these forests are a critical component of Earth’s biosphere and great urgency should be placed on preserving them.”(2) (emphasis added)

As if this misrepresentation of the facts weren’t bad enough, we find in Appendix A of the EIR that this isn’t the first time that someone has informed the authors of the EIR that this statement is not accurate.  One of the public comments submitted in 2009 in response to the Initial Study quotes Ken Caldeira’s op-ed in the New York Times.  Yet, two years later, the author of the EIR persists in repeating this misrepresentation of Professor Caldeira’s (Stanford University) research.  One wonders if the public comments were even read, judging by the repetition of the pseudoscience in the Initial Study that the public commented on in the first round.  It seems that the “public process” is merely going through the motions.

Grassland does NOT store more carbon than forests

The EIR also claims:

“Research studies have concluded that grassland and scrub habitat could act as a significant carbon sink.” (page 457, cited studies(3))

Once again, the cited study does not support the statement in the EIR:

  • Again, the statement has been taken out of context.  The entire sentence reads, “We conclude that grasslands can act as a significant carbon sink with the implementation of improved management.”  This sentence appears in the abstract for the publication.(4)
  • One wonders if the authors of the EIR read the entire article or just the abstract.  The point of the study is that land management techniques such as fertilization, irrigation, introduction of earthworms, plowing and fallow techniques, etc., can improve the sequestration of carbon in the soil of croplands and pastures.  This study is obviously irrelevant to the Natural Areas Program, which is not engaged in agriculture or pasturage and will not use any of these techniques. 
  • However, the study is relevant in one regard.  It reports that when forest is converted to grassland, no amount of “management techniques”  compensates for the loss of the carbon in the trees that are destroyed:

“Though more than half of the rain forest conversion studies (60%) resulted in increased soil Carbon content, net ecosystem Carbon balance…decreased substantially due to the loss of large amounts of biomass carbon.” 

The second study cited in support of the claim about carbon storage in grassland reports that increased levels of Carbon Dioxide in the air increases carbon accumulation in the soil.  This study tells us nothing about the relative merits of grassland and forests with respect to carbon storage.  Another study reports a similar relationship between global warming and carbon storage in trees:  “…warmer temperatures stimulate the gain of carbon stored in trees as woody tissue, partially offsetting the soil carbon loss to the atmosphere.” (5)

A pointless debate that misses the point

The misuse of these studies illustrates one of the fundamental issues with this pointless debate about the relative merits of grassland and forests.  Even if grassland were superior to forests with respect to carbon storage—and it’s NOT—it would never compensate for the loss of carbon associated with destroying a forest that is storing hundreds of thousands of tons of carbon.  The merits of planting trees where none presently exist is a fundamentally different argument than the merits of destroying trees.  The trees are here now.  No amount of grassland will compensate for the loss of the carbon presently stored by the forest that native plant advocates demand be destroyed.

If there is a sound argument for destroying trees, this isn’t it.  Grassland does not store more carbon than trees and will never compensate for the loss of the tons of carbon released into the atmosphere when trees are destroyed. (Please visit our post Facts about carbon storage do not support assumptions of native plant advocates)  Native plant advocates would be wise to abandon this particular line of unreasoning. 

Although we are not scientists, we read the work of scientists.  The studies conducted by scientists are not theoretical speculations about the benefits of one plant compared to another.  Rather they report the results of controlled experiments, such as actually measuring the amount of carbon in the plant and/or soil and reporting the results of those experiments.  Native plant advocates would be wise to spend less time trading baseless generalizations amongst themselves and spend more time reading the scientific reports of actual evidence. 

Please comment on the Draft Environmental Impact Report for the Natural Areas Program

Please keep in mind that the public will have an opportunity to comment on the proposal to remove thousands of trees in the city’s parks.  There will be a public hearing on October 6, 2011, and the deadline for submitting a written comment is October 17, 2011*.  Here are the details about the public’s opportunities to comment on the EIR for the Natural Areas Program:

“A public hearing on this Draft EIR and other matters has been scheduled by the City Planning Commission for October 6, 2011, in Room 400, City Hall, 1 Dr. Carlton B. Goodlett Place, beginning at 1:30 p.m. or later. (Call 558‐6422 the week of the hearing for a recorded message giving a more specific time.)”

“Public comments will be accepted from August 31, 2011 to 5:00 p.m. on October 17, 2011*. Written comments should be addressed to Bill Wycko, Environmental Review Officer, San Francisco Planning Department, 1650 Mission Street, Suite 400, San Francisco, CA 94103. Comments received at the public hearing and in writing will be responded to in a Summary of Comments and Responses document.”

*[ETA:  The deadline for written comments has been extended to October 31, 2011 at the request of the Planning Commission.]

“If you have any questions about the environmental review of the proposed project, please call Jessica Range at 415‐575‐9018.”


(1) Jha, Alok.  The Guardian.  “Planting Trees to Save Planet is Pointless, Say Ecologists.”  Friday, December 15, 2006.

(2) Caldeira, Ken, “Planting trees is far from pointless.” The Guardian, December 16, 2006.

(3) Conant, L., Paustian K, and Elliot E. 2001. “Grassland Management and Conversion into Grassland Effects on Soil Carbon.”  Natural Resource Ecology Laboratory.  Colorado State University. Fort Collins, USA.  Sponsor:  US Environmental Protection Agency, Ruminant Livestock Efficiency Program.  2001, and

Hu, S., Chapin, Firestone, Field, Chiariello.  2001.  “Nitrogen limitation of microbial decomposition in a grassland under elevated C02,” Nature 409:  188-191. 

(4) Conant, Paustian, Elliott, “Grassland Management and Conversion into Grassland Effects on Soil Carbon,”  Ecological Applications, 11 (2) 2001, 341-355.

(5) Melillo, J., Butler, S., Johnson, J., Mohan, J., Steudler, P., Lux, H., Burrows, E., Bowles, F., Smith, R., Scott, L., Vario, C., Hill, T., Burton, A., Zhouj, Y, and Tang, J. Soil warming carbon-nitrogen interactions and carbon-nitrogen budgets. PNAS, May 23, 2011

 

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