HOW OAK TREES AFFECT GLOBAL WARMING
California Oak Report,
Oaks & Climate Change
California Attorney General Edmund G. Brown, Jr. (AG) has reached a landmark lawsuit settlement with San Bernardino County involving the extent to which the County’s environmental impact report for its General Plan update should address impacts on climate change. This is the first time any California jurisdiction has entered into a legally binding agreement to look at the overall impact of its planning on global warming.
The agreement solidifies climate change as an impact to be addressed in California Environmental Quality Act (CEQA) environmental review documents. Significant impacts to oak woodlands must be addressed in CEQA green house gas reviews because oak impacts uniquely combine carbon capture and carbon emission issues.
According to the AG, discretionary approvals must provide: (1) An examination of a project's impact on climate change and the adoption of all feasible mitigation measures to reduce such impacts, and (2) such analysis can – and must – be done today even absent established thresholds of significance or impending regulations under Assembly Bill 32. The state’s California Climate Action Registry, which will guide AB 32 regulations, recognizes that converting oak woodlands to development is a carbon emission due to lost forest photosynthesis. Moreover, many municipal and county codes have general or specific tree-related provisions that reference air quality, air pollution or climatic conditions.
Consistent with the CEQA opinions of the AG, where significant oak resource impacts occur, project air quality analyses must consider three oak resource factors: (1) How much carbon is sequestered in the impacted oak trees?; (2) How much potential carbon sequestration will be lost due to oak seedling, sapling and tree impacts?; (3) How much sequestered carbon will be released if the impacted oaks are burned?
The CEQA Oak Woodlands Dilemma
The oak woodlands circumstances are unique for each CEQA project. Unfortunately, project oak woodland mitigation measures consistently fail to provide proportional habitat mitigation. The basic problem is a failure to see the forest for the trees, exemplified by the fact that invariably mitigated negative declarations and environmental impact reports biologically analyze oak woodlands but mitigate for individual oak trees.
On-Site Conservation Easement Mitigation
Impact avoidance through on-site oak woodlands conservation easement serves only to limit the degree of significant oak woodland impacts and the project applicant’s oak woodlands mitigation responsibilities. An on-site oak preserve amounts to nothing more than a promise not to further remove or fragment the remnant oak resource; these preserves do nothing to proportionally mitigate for the actual impacts from removing project site oak habitat.
Placement of an oak woodlands easement within a development is of marginal habitat value and also creates a potentially hazardous fire condition. Residual or planted oaks are at great risk of future loss through new Cal Fire fuel reduction regulations and increasingly stringent fire insurance policy standards.
On-Site Tree Planting Mitigation
Projects rarely have enough suitable land available for purposeful on-site oak planting for habitat mitigation. In most cases, funds for on-site planting would be far better spent on off-site planting or dedicated to the state Oak Woodlands Conservation Fund to purchase local oak woodlands.
Those projects that rely extensively on planting oaks on-site for mitigation need to disclose the estimated total cost of planting, maintaining and monitoring mitigation oaks and present information documenting local projects that have successfully created oak woodland habitat for CEQA mitigation purposes.
Tree Transplanting Mitigation
Public Resources Code Section 21083.4 doesn’t recognize the transplanting of oaks as a feasible or proportional mitigation measure. Moreover, several scientific studies have demonstrated that the transplanting of established oak trees is not a viable CEQA oak habitat mitigation measure.
For example, Dagit and Downer (1996) observed over a four-year period that, “16 percent of the transplanted trees died, 20 percent were nearly dead, 24 percent were in decline, 32 percent were stable and 8 percent were improving....While the transplanted trees remained alive, they were no longer self sustaining natives, but rather high care exotics that required intensive, long term maintenance.”
Cumulative Impacts Mitigation
CEQA requires that projects provide a comprehensive cumulative impacts list of past, present and probable future projects impacting oak resources regionally or area-wide, including quantifying the extent and severity of those oak habitat impacts.
County Mitigation Banks
All stakeholders should support establishment of county lists of landowners interested in the benefits of oak woodlands mitigation banking. These banks would serve project applicants seeking off-site oak woodland mitigation options, either through the restoration planting of oaks off-site or the purchase of off-site conservation easements on existing oak woodlands. Local or state conservation organizations would administer the oak woodland easements.