Redwoods as Climate Change Champions

Researchers are discovering that redwood forests are an excellent hedge against rising levels of atmospheric carbon.

by Maya Desai

Nov. 16, 2014—Living in Santa Cruz County, we’re all proud of our local heritage of redwood trees. But research from the Redwoods and Climate Change Initiative (RCCI), a group of scientists supported by several groups including the Sempervirens Fund and united in their drive to understand redwood trees, shows that redwoods are even more special than previously thought. They are also more at risk.

First up is why redwoods are so special. Mature coast redwoods are champions at sucking carbon out of the atmosphere and stockpiling it. All plants absorb and break down carbon dioxide, using it to build plant tissue. Over decades of growth, this process, called carbon sequestering, builds up a massive reserve of carbon within plants. In fact, there is more carbon in forests than in the entire atmosphere. This means forests are important buffers in the battle against climate change. Because redwoods grow keep growing wider after they attain their (immense) full height, old-growth redwood forests sequester three times more carbon than any other forest.

As well as their contribution to global carbon sequestering, redwood trees are movers and shakers in their own communities. Even in the heart of summer, redwood trees draw water to their entire ecosystem. The dense loam of redwood soil filters and stores water, quenching the thirst of local plants during the dry season. What’s more, these prehistoric trees have evolved to weather the dry California summer by filtering water out of fog. The water drips down into the soil and eventually finds its way to streams, replenishing the streams and everything that depends on them. A Stanford researcher found that some older redwoods in the Santa Cruz Mountains generated 38 inches of fog drip in 2.5 months. That's almost the amount of rain that Seattle gets in a year!

The trusty fog drip is becoming less reliable, though. Climate change is altering fog patterns. Worryingly, fog has declined by 30 percent in the past 60 years. While sun worshippers might rejoice at this statistic, this could be bad news for redwood trees. As the climate shifts, we can expect a warmer, windier, more wildfire-prone northern California.

To keep our forests healthy, we can protect old growth forests, minimize forest road densities, and increase wildlife connectivity within forests. If you want to learn more about RCCI, the Sempervirens Fund, and amazing facts about redwoods (like how many redwoods it takes to store one person’s worth of carbon emissions), head on over to the Sempervirens Fund to read a report on some of the RCCI's findings.