Beyond the farms and ranches of Denmark, Oregon, the land is wild: mountain and forest, streams and rivers.
Between the Pistol and the Rogue Rivers, there's Willow Creek and Crystal Creek, the Sixes River, and the Elk.
The emerald green Elk River winds down from the Coast range mountains, past tree-shaded banks. And riding the Elk's currents to the sea are Chinook salmon.
Wild Chinook, and Chinook from the Elk River Hatchery.
Robin Crisler runs the hatchery for Oregon Fish and Wildlife.
Robin Crisler: "I can't verify it, I don't have evidence in front of me, or references to cite, but the North Fork of the Elk River is reputed to be single best salmon steelhead producing stream for its size in the lower 48."
Christy George: "Are you sure you want this on the radio?"
Robin Crisler: "Well maybe I'm just bragging a little bit but our water quality is very good.
Robin Crisler: "This stack of incubators has the capacity to incubate approximately 75K plus eggs at one time."
From the hatch house to the outdoor rearing ponds, the Elk River hatchery nurtures fall and spring Chinook, steelhead and rainbow trout until they're ready to begin their journey.
Robin Crisler: "Right now, they're eating about 16 lbs a day. There's a bucket of fish food for our trout."
The salmon cycle drives hatchery and wild fish from their home river to the ocean and back again to the river to spawn.
Robin Crisler: "They're going to the smell of the pond, is what they're going to. They'll smell Elk River, and the smell of Elk River is the last thing you smelled when they exited the river to go into the ocean like you or I. If you remember the smell of strawberry jam your mother made or cinnamon rolls your grandmother made. That smell, obviously, triggers a memory instantly – so salmon are mapping their way by scent. "
Salmon need just three things, says Bill Peterson of Oregon State, and the National Oceanic and Atmospheric Administration.
Bill Peterson: "They need cold water, they need to find something to eat and they need to avoid being eaten."]
On all three counts, climate change is likely to stress salmon.
First, water, which moves in a cycle, too.
It all starts as snow on the mountains, which melts in the spring and rushes down rivers in a freshet that helps carry fish to the ocean.
Water in the ocean is evaporated into the atmosphere, where eventually, it falls again as rain or snow, and on and on.
But the climate is changing that cycle.
Bill Peterson: "The first thing we know almost for certain is that there will be less snow in the wintertime, and there'll be more rainfall. If there's less snow, that means the streams will be warmer than the salmon are used to."
And that affects hatchery fish as well as wild salmon.
Robin Crisler: "If the temperature goes up in the river, it goes up in the pond. The water you see here pumping out of the supply line to the hatchery is river water. It was pumped about ten seconds ago at our hatchery intake."
Robin Crisler: "Temperature is a big issue. If temperature elevates in the river very much, we watch the fish pretty carefully. We don't want them to stress out over that. Of course, as the temperature goes up, oxygen goes down and there are organisms that thrive at higher temperatures."
What Robin Crisler means by organisms is parasites or bacteria.
But people may be able to help control conditions in the river – and by extension, the hatchery.
Bill Peterson: "We can actually work on their habitat. We can make things better, plant trees on banks of streams to keep the water cooler."
When the fish reach the ocean, though, they're encountering changes too big and too complex to reverse.
For starters, a lot more carbon dioxide.
Burke Hales: "We've naturally got a system that's poised right on the brink."
Oregon State chemical oceanographer Burke Hales has studied seawater not far from Denmark, Oregon.
Burke Hales: "We know very precisely how much carbon dioxide has been released into the atmosphere since the beginning of the industrial revolution. What we don't find when we go look at the accumulation of carbon dioxide in the atmosphere is we don't find all of that – maybe half."
For a long time, scientists wondered where that missing CO2 went. Then they found it - in the ocean.
Burke Hales: "So the ocean is taking up something like a quarter or third of the human-released carbon dioxide, and we thought for the longest time that was this great thing."
But what scientists found next was alarming.
Burke Hales: "This is almost sort of chemistry 101."
Burke Hales says carbon dioxide is reacting with seawater to form carbonic acid.
Burke Hales: "And all this carbon dioxide uptake is changing the chemistry of the ocean. We're talking about changes in ocean chemistry that we've probably never seen in geological record – and the magnitude of the change and the rapidity of the change are such that it's very hard for these organisms to adapt."
Mark Hixon: "Animals that have limestone skeletons or calcium carbonate skeletons, those skeletons will start to dissolve."
Oregon State zoologist Mark Hixon has surveyed undersea life on the ocean floor near Denmark, Oregon.
Mark Hixon: "Oceanographers have started to measure the acidity of seawater around the globe – and astonishingly what they're finding is some of the lowest PHes – that is, the most acidic water is right off the southern Oregon coast."
Hixon says the most abundant species at risk out there are sea urchins and hermit crabs.
Mark Hixon: "When you remove an abundant organism from any ecosystem, almost always we see effects that don't please us as humans. Hermit crabs, for example, are very important scavengers on the sea floor. They help clean up sea floor of dead stuff. So what would effect be on land if we lost dung beetles? Well, people don't eat dung beetles but without them, there'd be a lot of dung."
And what about the salmon?
Bill Peterson: "It all starts with the food chain, that's where it all begins."
Salmon eat small fish that eat even smaller plankton, says Bill Peterson. But if the ocean is warmer, what shows up is a new kind of plankton from warmer waters.
Bill Peterson: "These are like subtropical animals with this kind of mañana attitude, they don't have any plans for tomorrow - it's 'tomorrow will be like it was today.' They're not fat, they're kind of skinny and when that's the basis of your food chain, the little fish the salmon eat aren't fat and the salmon don't get fat."
And skinny salmon can't always out-swim their predators, or even make it back home to spawn.
Bill Peterson: "If there's one thing we can expect from climate change, it's variability. If there's more variability, how can you predict anything? And the fact is, that you can't."
Bill Peterson says there are other climate cycles – like one called the Pacific Decadal Oscillation, which cycles from warm phases to cold phases about every 20-25 years.
At least - until recently.
Bill Peterson: "So we've had three phase changes from warm to cold, warm cold, cold warm in the last ten years. Which has never happened before. This is kind of what you'd expect from climate change, and if salmon have to deal with this on a year by year basis, they're in big trouble. If you think they can maybe adapt to this, there's no way. It's really kind of sad."
Robin Crisler says salmon are good at adapting to change.
Robin Crisler: "I cite the example of the Toutle River off of Mt. St. Helens – a complete disaster, and the river was ruined, but today, within far less than our lifetimes there are salmon and steelhead in the Toutle River again."
Bill Peterson wants to believe.
Bill Peterson: "They're tough, they're resilient, and if there's an animal that's going to survive and make it in climate change, it's the salmon. I mean they will find a way. I really firmly believe that. But we've got to help them any way we can. And hope for the best."
Christy George produced our program and the audio editor was Steven Vaughn Kray.
We'll return to Denmark, Oregon, in November, just before the climate treaty summit in Copenhagen.
You can read other stories on our Denmark Project page.