Forest Offsets and Fuzzy Math in the Angeles National Forest

Station Fire near Briggs Terrace, Aug. 29, 2009

I previously posted that Sierra Club wants Governor Brown to re-examine forest offsets under California’s cap-and-trade program. One of the commenters to that post wondered if the plan to plant 10,000 acres of trees in the Angeles National Forest was an example of such an offset. Now I don’t know if that planting would count for offsets in AB 32’s cap-and-trade program, but it is certainly an attempt to offset carbon emissions from Chevron’s El Segundo refinery. In order to expand Chevron’s refinery, Chevron was required to make greenhouse gas emission reductions as part of the environmental analysis.

161,000 acres in Angeles National Forest burned in the 2009 Station Fire. The National Forest Foundation and the U.S. Forest Service plan to replant 10,000 acres with a variety of coniferous trees.  (The rest of the acreage is chaparral and riparian environments.) South Coast Air Quality Management District (SCAQMD) has generously donated $1.5 million in “mitigation fees” from the Chevron El Segundo plant, presumably to offset the refinery’s carbon emissions. Two questions come to mind: is the restoration ecologically sound and are those offsets real?

Some have questioned the choice of conifers for replanting (or the idea of replanting at all). The mix includes big cone Douglas fir, Coulter, Jeffrey, and Ponderosa pines, and incense cedar. Given climate change, the forest is slowly converting to a chaparral biome, so Nancy Steel questions whether the new plantings will survive.  Jon Keeley, a U.S. Geological Survey biologist, objects that you shouldn’t plant Coulter pines in what was a Douglas fir forest. Forest offset programs are rife with this type of controversy. If you want a lot of offsets for your money, you need to plant trees (not shrubs). And some trees are cheaper or easier to plant than others. Such economic considerations often don’t coincide with ecological considerations.

I also wonder if anyone has seriously considered the math behind these offsets? Here is Sam Atwood from SCAQMD:

The trees are going to be sequestering carbon dioxide for the next hundred years. . . . It will make a difference in the Los Angeles area.

SCAQMD estimates that the replanting will offset 280,000 metric tons of CO2 emissions from the refinery. Now, I won’t get into the wisdom of operating a refinery that, in Chevron’s words, “is wedged between two residential communities on the Santa Monica Bay.” But I do have some questions about whether these offsets make a bit of difference to Los Angeles’ greenhouse gas emissions.

Does letting Chevron count the replanting of a burned forest against its refinery emissions amount to double-counting? The forest had stored carbon for, let’s say, one hundred years. Then it burned in 2009, releasing much of that carbon into the atmosphere. Replanting could, in theory, re-capture an equivalent amount of carbon over the next one hundred years. But by 2109 we have—at best—only reached the status quo that we began with in 2009, before the fire. How much refinery emissions have been accounted for with the planting? Zero, by one estimation. The Forest Service did not need to obtain emissions allowances when the forest burned. Yet it now creates credits when the forest is re-grown.

But, you might say, that forest would never regrow without our intervention. So it is still a net reduction in emissions, given that we have no forest in 2011 and forest in 2109. But we aren’t planting a forest on a golf course, or an abandoned parking lot. This is a national forest. Chevron (through SCAQMD) is spending $1.5 million to protect tree growth in an area that already protects tree growth, and calling that mitigation. This fails one of the tests for forest offsets: that the offset be additional.

Photo courtesy

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Reader Comments

3 Replies to “Forest Offsets and Fuzzy Math in the Angeles National Forest”

  1. Carbon offsets have no effect whatsoever on climate change and never will. Carbon offsets are for fools.

  2. Still not clear on what’s driving this. If AB32 has yet to be implemented, how can a state agency can require mitigation of GHG’s. Under a different law? Or is this a kind of offset banking that assumes GHG regulation in the near future?

    It’s strange that such a thing can happen–offsets fueling questionable forestry practices in a Nat’l Forest–and yet no one knows much about it. I read a post on Legal Planet (Prof Hecht?) defending the environmental justice groups’ case against AB32. Direct regulation of GHG’s would, unlike reliance on market mechanisms, give citizens the opportunity for input on decisions to license any increase in emissions.

    Some rambling thoughts on the forestry. The photo in the linked blog posting–that’s the north side of Wilson, you can see the Mt Wilson road cutting up slope–shows burned chaparral, but intact forest. The north side of Wilson definitely has a complex mix of trees, some very big, lots of stuff besides pine. You can see that in the photo. Some could even be old growth.

    As far as the hot fire killing the seeds. Who really knows? Others–including a professor emeritus from UC whose name I can’t remember–increasingly think this kind a of fire was normal for chaparral. The chaparral didn’t burn frequently, it burned in mega events–lightning triggered fires that smoldered all summer and then blew into giant conflagrations when the Santa Anas kicked up in the fall; fires, in scope, like the Station Fire.

    It takes decades for the dominant manzanita and chemise become established. There are stands of mature manzanita (Mt Figueroa, n of Santa Barbara perhaps) that haven’t burned for a hundred years. The problem with the frequent fires has been the establishment of invasive plants–leading to even more frequent fires and permanent loss of native chaparral. Trying to manage chaparral with controlled burns may be to guarantee its loss. For this reason I question the notion that forests in the San Gabriels are converting to chaparral. Changes are happening, but both native chaparral and forest are threatened with loss.

    I’m not convince we know enough about the forest to do reforest with a million Coulter saplings, plantation style. It’s not clear to me how the Coulters supposed to out-compete the non-native grasses.

    Does nature cycle or is an ecosystem just as likely to ba a one-time occurrence, the result of a random chain of events? Sometimes things grow back, sometimes they don’t. I imagine without enough shade, humidity and protection from erosion, it would be very hard for trees on many of those slopes to get established. In other words, trees change their environment, making it more hospitable for trees.

    Trying to read up on this controversy, I came across a comment in a blog post–a reference to a reference. Apparently, the south-facing slopes of the mountains above Glendale and La Crescenta-Flintridge were forested with Big Cone Douglas Fir. But that was harvested to fuel brick kilns in the late 1800’s. It’s not expected to ever grow back. Similarly, I’ve wondered if that’s the reason for the dense brush in the narrow canyons feeding the San Gabriel. Were the trees all taken out by miners and loggers? Like the grizzlies, a one-time harvest?

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