A hefty stack of reports issued by a top national science board appears to affirm California’s response to the challenges of climate change.

The National Research Council, an arm of the National Academies of Science today released three reviews of the current climate science, each focusing on a different aspect of it. The first report, a 400-page assessment of the state of the science, affirms the prevailing view among scientists that global warming is proceeding apace, propelled largely by emissions of greenhouse gases, and that some of the early impacts are already upon us.

Stanford’s Pamela Matson, a specialist in biogeochemical ecology and lead author of the science assessment, said these conclusions are supported by “multiple lines of evidence” and have “stood firm” in the face of intense scientific scrutiny. Matson conceded, however, that much uncertainty remains in the science, and that the credible range of global warming projections runs from two, to eleven degrees, Fahrenheit, by the end of this century.

Two companion reports focused on mitigation and adaptation strategies, respectively (for a closer look at the latter, see Nicole Heller’s post at Climate Central).

Robert Fri, who led the NAS panel on “limiting the future magnitude of climate change,” said that federal policies should “enable flexibility and experimentation in policies at state & local level.” Fri cited California and Alaska as leaders in climate response policy at the state level. Mary Nichols, who chairs California’s Air Resources Board and effectively heads the implementation of the state’s climate strategy, also sits on the “Limiting Panel” of the NAS review. Nichols has been a vocal promoter of state and regional efforts, such as the Western Climate Initiative.

When queried about pending federal legislation that might nullify state programs to regulate carbon, Fri said that “the bar ought to be pretty high for federal preemption. States have already done a lot,” he said, and it’s important not to act in a way that reverses the progress.”

Likewise Fri’s colleague, Tom Wilbanks, head of the study’s adaptation panel, said that what’s needed is “not a federal response but a national response,” and that Washington’s role should be to “create a framework” of policies and resources that “reinforce each other rather than get in each others’ way.”

The recommendations come as California’s sweeping 2006 climate strategy, known widely as AB 32, is under attack from Republican gubernatorial candidates and a well-funded initiative campaign to suspend most regulations under the law. Likewise both the House and Senate bills pending in Washington would either preempt or temporarily freeze state programs to reduce carbon emissions.

Fri also provided the morning’s most eyebrow-raising moment when he said that current technology will not be up to the task of reducing warming.  “We can’t get there by just deploying what we know how to do,” he said, noting that brand new technologies will be required. “And we probably won’t be doing it at least cost,” he added.

The NAS reports released today do not recommend specific targets for GHG emissions. The three reports are the first in a series of five requested by Congress as part of the program called America’s Climate Choices.

A webcast of the one-hour public rollout of the reports is available at the NAS website.