California Cycles Part I: The Fog-Fed
How Northern California's Climate Creates Our Forest Treasures
After a week abroad in a hot and humid, mosquito-filled landscape, returning home to the San Francisco Bay Area fog felt like breathing life itself back into my lungs. Growing up with the fog makes locals long for cold nights and hot summer nights more tolerable knowing the fog is not far away. And that familiar rolling bank of fog over the coastal range isn't just a scenic backdrop—it's the lifeblood of one of the world's most extraordinary ecosystems, and the secret behind California's architectural heritage.
The fog that blankets Northern California is more than moisture; it's a delivery system for survival. Our coastal redwoods depend on it for 60% of their water intake, pulling precious droplets directly from the air through their needles in a process called foliar uptake. While Southern California occasionally benefits from marine layers, nothing compares to the consistent, life-giving fog that nurtures our northern forests. This unique climate relationship has created something irreplaceable: old-growth redwood forests that store more carbon per acre than any other aboveground forest on the planet.
These fog-fed giants are living monuments to time itself, with rings telling tales of earlier centuries and millennia. Before the Gold Rush of 1850 brought massive changes to California, ancient redwoods covered 2.2 million acres of coastal forest. Individual trees created cathedral-like groves where Spanish explorers once marveled that the land "looks like a well-tended garden." What they witnessed was indeed carefully tended—by Indigenous peoples who had maintained these forests for millennia through cultural burning practices and regenerative harvesting.
In barely more than a century, 95% of all old-growth coastal redwoods were harvested, reducing the original forests to just a little over 100,000 acres. These weren't just trees; they were entire ecosystems. A single acre of even second-growth redwood forest absorbs 339 metric tons of carbon—equivalent to taking 270 vehicles off the road for an entire year. The original old-growth forests stored exponentially more.
But here's where the story becomes deeply personal for anyone who appreciates California's architectural heritage: those fog-fed giants didn't just disappear. They became the skin and bones of our most beautiful homes. The redwood that graced Victorian exteriors in San Francisco, the massive beams that supported Craftsman bungalows, the siding that has weathered decades on coastal cottages—all of it came from trees that had been drinking fog for centuries.
Redwood's unique properties made it California's signature building material. Its natural resistance to pests, moisture, and decay meant homes could stand for generations with minimal maintenance. The wood's beauty—those rich, straight grain patterns in shades from pale gold to deep burgundy—made it as much about aesthetics as durability. Yet redwood's relative softness (twice as soft as fir on hardness scales) meant it was primarily used for siding, trim, and finish work rather than structural framing, making each piece that much more precious.
Today, when we deconstruct a 1920s bungalow in Berkeley or carefully remove siding from a Marin County cottage, we're not just salvaging lumber—we're rescuing pieces of an ancient forest that can never be replicated. Every board we reclaim is wood that doesn't need to be harvested from the 1.6 million acres of coastal redwood forests currently regrowing. Those second and third-growth forests, while valuable, will take centuries to develop the carbon storage capacity and ecological complexity of their predecessors.
This is where the fog connection becomes critical for our future. Climate change is altering the marine layer patterns that redwoods depend on. Warmer ocean temperatures and shifting weather systems affect when and how much fog reaches our forests. The "atmospheric sponge" effect—where warmer air holds more moisture—creates a cycle where more water is pulled from plants and soil during dry periods, then released in concentrated bursts during storms.
The recent devastating fires in Los Angeles remind us that we're not just losing forests to flames—we're losing the architectural heritage those forests created. Historic homes in Altadena and Pacific Palisades contained irreplaceable old-growth lumber that took centuries to grow and mere hours to burn. Each lost structure represented not just shelter and memories, but embodied carbon and craftsmanship that connected us to California's fog-fed forests.
Understanding this connection—between fog and forest, forest and home, climate and culture—is essential as we face an uncertain future. The redwoods that remain are more precious than gold, and the lumber already harvested from their ancestors deserves the same reverence. When you choose reclaimed redwood over new harvest, we're allowing those regrowing forests crucial time to mature, to rebuild their carbon storage, and to once again become the fog-fed giants that make California's landscape extraordinary.
In our next installment, we'll explore the architectural legacy that emerged from these ancient forests—and what we lost when the flames came to Los Angeles.
Photo credit: Brandon Bugge from recent deconstruction project in Mill Valley.