Sand dunes near Stovepipe Wells, in Death Valley. Photo: Craig Miller.

Now, okay, "quiet" is a somewhat subjective thing. When I lived on the upper (way upper) west side of Manhattan in the 1980s, any interval without hearing a car alarm seemed like blessed relief. Quiet can be measured, of course, with sound pressure meters. Anything below about 40 decibels is pretty darn quiet for most people's purposes.

The National Park Service (NPS) says the quietest place it has yet measured is a spot in Great Sand Dunes National Park, where Vicki McCusker, who helps oversee the natural sounds program for the Park Service, says it was "bottoming out" their meters.

I've never been there but it's hard to imagine greater quietude than an afternoon I spent in Death Valley. Coincidentally this was also on a sand dune, near Stovepipe Wells. It was also Christmas Day, which kept the tourist traffic to a minimum. It was at a point in my life when I was in desperate need of some deep introspection, so I parked my car along Highway 190 and trekked into the dunes, found an accommodating slope and sat down. Occasionally a fly (or something) would buzz by. Other than that, the loudest thing was the buzzing in my own head, which I can only hope would've been inaudible to anyone with me.

It's interesting how, when things get really quiet, our bodies try to make up for it with ringing ears and internal chaos. The noted bioacoustician Bernie Krause talks about the time he and his wife, Kat were hosting guests from New York, who literally had to leave the Krause's semi-secluded Glen Ellen "sanctuary" because the night-time quiet was creeping them out.

I asked Krause what he could draw from that. "Well, it tells me that we’re more insane than I ever thought in the first place," he mused. "I mean, we’re definitely verging on pathological.  Because it’s exactly those kinds of sounds–the urban acoustic envelope in which we enfold ourselves–that kind of urban noise that’s driving up the numbers of prescriptions for Prozac."

Surveys of national park visitors would seem to bear that out.  In the early 1990s, NPS surveyed 15,000 visitors in 39 parks, about noise issues (NPS manages 391 "units" nationwide, 58 of which are designated as "parks"). More than nine out of ten visitors surveyed cited "enjoyment of natural quiet" as a reason for visiting. This survey provided some juice for the ongoing natural sounds program in the parks.

An open question is: where does it go from here? Much of the current effort in the parks appears to be geared toward developing "air tour management plans," a response to concerns that first arose over the increasingly crowded skies above the Grand Canyon. McCusker told me that while aircraft overflights are the most pervasive noise issue across the parks, the most common complaint is probably over loud motorcycles (note to "straight-pipe" Harley owners).

Krause, who conducted a year-long project documenting soundscapes in Sequoia-Kings Canyon National Park, hopes the research will also be used to develop new rules governing on-the-ground noise pollution. "If the parks can set aside places where people can go and hear the natural world as it is, at any season of the year, then that will be a really big benefit for visitors coming to the parks," he says. "Otherwise, you’re seeing the parks with the wrong soundtrack. It’s like watching Star Wars without a soundtrack."

So check out this four and a half minute “journey” I produced with Bernie Krause, founder of Wild Sanctuary. It takes you from the familiar cacophony of the urban soundscape to a serene spot in Sequoia Park.

QUEST on KQED Public Media.

Listen to the radio report, "Soundscapes of National Parks" online.

The Public Policy Institute of California has been tracking public support for expanded nuclear power over the past several years. Survey participants are offered a menu of four potential energy options, one at a time.

The question posed is: "Thinking about the country as a whole, to address the country’s energy needs and reduce dependence on foreign oil sources, do you favor or oppose the following proposals?" Then the four options are offered, including: "How about building more nuclear power plants at this time."

As recently as 2002, adults surveyed in California opposed the idea by a margin of 59% to 33%. But that gap has been closing steadily in the years since and by this July, Californians were split just about down the middle on the question, with 46% in favor and 48% opposed. The poll has a margin of error of about 2%, making it a virtual tie.

When you dig into the numbers a little deeper, some demographic preferences emerge: support increases with both age and education. Californians 55 and older support more nuclear by a wide margin (58% to 36%) as do college graduates (50%-43%).

Many people use cost as an argument against nuclear but just as the PPIC was phoning around for opinions on the matter, the Palo Alto-based Electric Power Research Institute was finishing up its own report , concluding that trying to reach greenhouse gas reduction goals without baseload technologies like nuclear power, could end up costing much more. Dan Kammen, who runs an energy lab at U.C. Berkeley, would appear to agree. He said in a recent interview for Climate Watch that "Without knowing exactly where things will come down on nuclear, I think that it absolutely has to be part of the equation in a way that it has not been in the past. Energy costs from fossil fuels are rising at almost 5% a year now, and the damage we are doing and are going to do more of, if we don’t stop our fossil fuel expansion, in terms of greenhouse warming, is so large an issue that these technologies have to be back on the table.

But there's a serious question of whether the nation– let alone the state– is in a position to embrace nuclear as it did in the 1960s. Kammen is also a professor of nuclear engineering, and noted with some alarm the rate at which the industry is "graying." Now in his mid-forties, he told me that when he attends technical meetings for nuclear engineers, he's often "the youngest guy in the room–by 20 years." Since the U.S. more or less abandoned its nuclear hopes following the Three Mile Island debacle, the nation has ceded most of its nuclear industrial capacity to other nations, and few young people have chosen to enter the field.

The effective ban on new nuclear plants that California has had in place since 1976 could be reconsidered. But ultimately electric utilities will have to want it and I sense a certain "nuclear fatigue" in that arena.

The Sacramento Municipal Utility District (SMUD) shut down its only reactor in 1989, after a thumbs-down referendum. When I called to ask for an interview on the prospects for a nuclear revival, they declined. They didn't even want to talk about it. Managers at PG&E, whose twin reactors at Diablo Canyon produce nearly a quarter of the utility's output, still claim an interest in nuclear. But when I asked CEO Peter Darbee about it recently, he said he had the sense that most people in California would prefer to look elsewhere for energy solutions. Of course, that was before the latest PPIC poll.

Listen to the New Nuclear radio report online.

Check out an interactive "atomic timeline," marking some of the milestones in nuclear power history in the U.S. By former Climate Watch intern Amanda Dyer.

"2008 was one of the hottest years on record."

Just last week, Max Moritz and his team at UC Berkeley's Center for Fire Research & Outreach published a study that shows widely varied fire response to climate changes around the world. Post-doctoral fellow Meg Krawchuk was the lead data cruncher in the effort, with contributions from researchers at Texas Tech University.

What they found were suggestions of rapid changes in fire regimes, and not all in the same direction. Some places (like most of California) will likely see a spike in the fire hazard, while other regions (like the Pacific Northwest) could see a retreat of wildfire frequency and intensity:

"In contrast to any expectation that global warming should necessarily result in more fire, we find that regional increases in fire probabilities may be counter-balanced by decreases at other locations, due to the interplay of temperature and precipitation variables. Despite this net balance, our models predict substantial invasion and retreat of fire across large portions of the globe."

Moritz has been stumping for new approaches to fire-climate analysis. He says rather than treat fire strictly as the product of other climate change variables, we should think of it also as a climate driver.

Map shows areas of potential fire advance (orange) and retreat (blue) by 2010-2039 (medium-high emissions scenario)

You can use the player below to hear an excerpt from my interview with Moritz, in which he explains the new perspective that he thinks his team's study brings to the fire-climate connection.