KLINE, P. J. I agree with the majority that the SEIRs involved in this case were comprehensible to the decisionmakers. I do not believe it necessarily follows from this, however, that members of the affected public were also able to comprehend the documents. I write separately to affirm my belief that each SEIR was indeed also “readily understandable ... by interested non-professional laypersons likely to be affected by actions taken under [it],” as required by the Ninth Circuit standard we adopt (Oregon Environmental Council v. Kunzman (9th Cir. 1987) 817 F.2d 484, 494), and to clarify my views regarding application of that standard.
The Ninth Circuit test, like the guidelines that implement CEQA, require that the environmental impact statement be comprehensible not only to “decisionmakers” but as well to the affected public. (Cal. Admin. Code, tit. 14, §§ 15121, subd. (a), 15140.)1 Though it is conceivable that an EIR will be incomprehensible to decisionmakers — i.e., elected and appointed government officials as well as civil servants involved in the authorization of construction projects — it is far more likely that the document will be incomprehensible, if at all, to the lay public. This greater likelihood arises not only from the fact that many people are unfamiliar with the jargon sometimes [1551]employed in environmental impact analysis, but as a result of the technical complexity inherent in some advanced forms of environmental analysis. For example, a water or ambient air quality test may involve elaborate chemical analyses beyond the ken of even the well educated.
It will often be appropriate to employ complex scientific theories or techniques in an EIR. The requirement that the document be “readily understandable ... by interested non-professional laypersons,” cannot be deemed to preclude the use of such complex concepts, for then environmental analysis would have to be carried out without the benefit of many of the most useful ideas and techniques, to the detriment of those the analysis is supposed to enlighten. Fortunately, the conflict that may arise between the need to employ sophisticated scientific methods and the duty to communicate to scientifically unsophisticated people does not present an insoluble dilemma. A scientific theory or complicated analytic technique beyond the understanding of the average layperson may be employed in an EIR provided an effort is made to describe it as simply as possible and enough information is supplied to enable a qualified person to test the theory or technique. The portions of the EIR that must without compromise be understandable by the lay public are those which describe the project (CEQA Guidelines, § 15124) and which summarize (1) each significant environmental effect of the project together with proposed mitigation measures and alternatives that would reduce or avoid adverse effects; (2) known areas of controversy, including issues raised by public agencies and the public; and (3) unresolved issues, including the choice among alternatives and whether or how to mitigate significant adverse environmental effects. (CEQA Guidelines, § 15123.)
In the present case the portions of the SEIRs that are most difficult to understand are those that describe and employ two different analytical approaches to forecast land use change, employment growth, and residence patterns between 1984 and 2000, i.e., the assessment of “cumulative impacts.” These two approaches are referred to as the “Downtown plan forecast” and the “list-based approach.” The description of these two approaches set forth in the SEIRs2 and the manner in which they are applied, however, are not so recondite or complex as to be incomprehensible to most members of the public willing to take the time to read the documents. [1552]Moreover, the conclusions that result from their use are very easily understood. For example, under the highlighted heading “Significant Environmental Effects That Cannot Be Avoided If the Project Is Implemented,” the SEIRs all state the summary conclusion that although “cumulative impacts on energy use and housing demand have been mitigated to a level of insignificance .... [t]he project would be part of a trend of denser development in downtown San Francisco. The project would contribute to cumulative traffic increases on downtown streets and on freeways and bridges near downtown San Francisco, and would contribute to cumulative passenger loading impacts on Muni, Bart and other transit carriers. Mitigation measures are available which would reduce these effects on a system-wide basis; these mitigation measures could be implemented by the City and County of San Francisco and other agencies wi h jurisdiction over highways, bridges and transit systems but could not be implemented by individual project sponsors.”
It does not require a degree in city planning to understand this summary of the information provided in greater detail in the body of each SEIR; and it succinctly provides the crucial information of greatest interest to most who consult the documents.
Where, as here, the environmental impact report describes as clearly as possible the factual assumptions and analytical techniques relied upon and simply and succinctly summarizes the most critical information, the standard of comprehensibility we adopt in this case has in my view been satisfied. As correctly pointed out in the CEQA Guidelines, “[t]he courts have looked not for perfection but for adequacy, completeness, and a good faith effort at full disclosure.” (CEQA Guidelines, § 15151; see also, San Franciscans for Reasonable Growth v. City and County of San Francisco (1984) 151 Cal.App.3d 61, 81 [198 Cal.Rptr. 634].)
All subsequent citations to CEQA Guidelines refer to chapter 3 of title 14 of the California Administrative Code.
As stated in each SEIR, the basic general difference between these two approaches “is that the Downtown Plan approach accounts for changes to a range of land uses as well as changes over time in worker characteristics and behavior, while the list-based approach is limited to known projects of certain types and assumes unchanging characteristics and behavior. These two approaches are alternative means of assessing the future cumulative context for downtown development. They use different available data sources and different assumptions.”