- Redwoods are the tallest trees on Earth.

(gentle music) Every year, millions of tourists from around the world visit California's famous redwoods.

They're impossibly big, majestic, and symbols of Earth's ancient past, yet few people understand just how unlikely it is these last groves of giants still stand at all.

The story's pretty crazy actually.

The coast redwood is an evergreen conifer and the tallest tree species on Earth.

The tallest redwoods stand 350 to 380 feet in height, AKA 35 to 38 stories tall.

Let's get sciencey with it.

The main trunk on one of these giants can be up to 30 feet in diameter.

Not this one, though.

Redwoods began evolving 200 million years ago at the beginning of the early Jurassic period, arriving just after the dinosaurs.

They survived the breakup of the supercontinent Pangaea and the continental drift, and they managed to withstand raging environmental shifts.

66 million years ago, when that infamous meteor wiped out the dinosaurs and 75% of Earth, redwoods survived.

One of the craziest facts I've learned is that scientists suggest the oldest living redwoods may be somewhere between 2,000 and 3,000 years old, meaning those trees are roughly the same age as the Parthenon.

(gentle music) Besides their longevity, redwoods have a really cool superpower: their ability to absorb water from the fog.

Yes, you heard that right, redwoods can absorb up to 40% of their water each year from fog.

In addition to sipping from fog, redwoods also siphon carbon dioxide from the atmosphere.

Studies show that redwoods capture more carbon dioxide from our cars, trucks, and power plants than from any other tree on Earth.

Through the process of photosynthesis, redwood trees transform carbon dioxide, the leading cause of accelerating climate change, into the oxygen that we breathe.

While these enormous giants are incredibly resilient, scars from early logging mean a precarious future for these treasured redwood forests.

We spoke with legendary journalist and redwood activist Greg King to hear how much these forests have changed from logging.

- In the Redwoods, right now, there's 4% of the original ancient redwood still standing.

There's only 2% of mature second growth redwood still standing in the redwood biome.

No way to describe the before and after that kind of loss, and it took millions of years for this to get here, and a day for it to be gone.

Well, first, Native Americans came and they used redwood, but they didn't decimate the forest.

They didn't really dent the habitat at all because they only took what they needed.

That's the big difference.

And then you had the European settlers come to the redwoods and they saw the redwoods as a bank for building homes and for building cities.

- While commercial logging began in the 1850s, it was the post-World War II housing and economic boom that caused the majority of old growth redwoods to be clear cut.

In just a few decades, hundreds of thousands of acres of old growth redwoods on private lands were logged.

By the 1960s, industrial logging had removed almost 90% of all the original redwoods.

Nearly all of the ancient redwoods that stand today are found in five state parks, Jedediah Smith Redwoods, Del Norte Coast Redwoods, Prairie Creek Redwoods, Humboldt Redwoods, and Big Basin.

Greg was at the Center of activism in the '80s.

Things got a little bit spicy, like guns, death threats, and even car bombs.

- This is a 1989 blockade of a logging truck, and this was the family operation, three generations that were there.

His father disarmed him, and then his brother grabbed the gun and fired it into the air, and everybody scattered.

So that was our most dangerous action that we did, because he could easily have killed somebody.

Nobody stopped doing the work.

Maybe we were just kind of crazy at that point, I don't know.

- Things got so heated between activists and logging companies that, at one point, Greg's activist friends were victims of a car bomb.

- And this is what happens when you get too effective at halting industrial destruction, especially in the redwoods in those days, is you get a bomb placed under the seat of your car.

And logging, especially of ancient redwoods, has been compared to warfare, a war against the Earth.

It's not people that are being attacked, but it is a living force of life that is extremely rare, so we have an obligation, especially considering what we've done to these habitats to give back now.

Now is the time to give back, and I don't see humanity going in that direction, and I think that's one thing that disturbs me the most.

- Lessons have been learned from the past, and today, we see cooperation between activists and logging companies.

Instead of clear cutting an entire forest, they harvest about 5% of a given few acres while leaving behind the biggest trees.

Greg explains the benefit of this.

- [Greg] Rings are tighter, the wood is better quality, they get more money for it, so they cut less, get more money per tree, and then they use that money to buy habitat land elsewhere.

So it's really a great municipal system, in particular because it's managed for old growth characteristics.

The city wants this forest to continue growing as an old growth forest.

It's a major tourist draw.

As you can see, it's extraordinarily beautiful.

It's a good compromise.

- [Meg] Protecting redwoods is not only crucial for biodiversity and climate, but it's also important for community.

- We need to also be protecting these small pieces that interconnect over time to retain habitat while the planet goes through what is a significant transformation.

And if we can keep the pieces intact, even if it's been harmed in some way by logging or mining or whatever, to bring them back, to restore them, and to make sure that they are allowed to continue existing as viable habitat.

If you can look around and determine what needs doing right there, that can be the easiest way to do something in your own life.

It's not difficult to find out what's needed to be done.

The real difficult thing can be actually putting ourselves forward and doing it, but once you get started, it's like riding a bike.

- California's climate is undeniably changing, but the Coast Redwoods shows incredible stories of resilience.

These towering trees have endured for millennia, weathering countless storms and transformations.

Their history is marked by both civil disobedience and hard-won compromise.

We have so much to learn from these remarkable beings and our role as stewards to these incredible trees in our own backyard.

Until next time, happy exploring.

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