Shaking a Sleeping Bog Monster
The SPRUCE climate change experiment is warming a bog to study a potential greenhouse gas catastrophe
[IMPORTANT UPDATE, Tuesday, December 13, 2016: An early study shows ancient deep peat carbon may not break down into greenhouse gasses in the face of global warming. The story below has not been changed. It is the original story published before the completion of those new results, and must be understood in light of this new development. Follow this link to read the new news.]
With a bread knife, Joel Kostka stabs into the watery floor of a peat bog dedicated to scientific study. The serrated blade sounds like it’s sawing through a soaked loofa laced with toothpicks.
Kostka is one of dozens of researchers who have come to northern Minnesota’s Marcell Experimental Forest to get a good look at a behemoth made of carbon. It’s buried under the fluffy moss, but in a globally warmed future, scientists postulate, it will transform into greenhouse gases and accelerate climate change.
The U.S. Department of Energy is testing the hypothesis in a wide-ranging experiment called SPRUCE, which stands for Spruce and Peatland Responses Under Climatic and Environmental Change.
SPRUCE is artificially warming the whole bog ecosystem in sections from below the plant roots up to the treetops.
“There’s no other large experiment like this of its kind,” said Kostka, a microbiologist and professor in Georgia Tech’s School of Biological Sciences and School of Earth and Atmospheric Sciences. “The idea is to warm the soils from the bottom up.” The research should mimic global warming like nothing before it.
Here, have a slice
Scientists are monitoring the altered ecosystem with particular attention to deep, carbon-rich peat — most of it is millennia old, brown, and muddy. It goes down some 15 feet.
Kostka picks up a sopping, moss-covered chunk from the surface and holds it out in his hand. A small, pale, bulbous bug falls out of it as he points out the layers. “You can see the green material and then the beginnings of the decomposing Sphagnum in the peat.”
Sphagnum is the scientific name for the peat moss plant. “The leaves of a peat plant are just one cell thick,” Kostka marvels. Inches under the green sprigs are yellowed ones, then the deep brown goo starts.
“Peat moss turns out to be a hugely important plant globally,” Kostka said. “It arguably stores more carbon than any other plant on Earth.”
Legendary bog monster
Folklore has embellished bogs with gooey monsters interred beneath the squishy moss, waiting centuries to resurrect so they may rise up to wreak havoc.
Horror movie hooey — but it’s a great metaphor for the worst case scenario of what lies deep inside cold, or boreal, peat bogs in parts of northernmost North America and spanning northern Europe and Siberia.
For some 10,000 years, Sphagnum has been sucking carbon gases out of the atmosphere. Then, as it died and sank, it took megatons of carbon down with it, packing the carbon compounds virtually airtight and refrigerating them at temperatures of around freezing.
“We call it a carbon bank, because a lot of the carbon that’s present in terrestrial soils is present in these peats,” Kostka said.
Exploding oil refineries
Though boreal bogs cover just 3 percent of Earth’s land surface, they have banked more than 30 percent of the world’s soil carbon. Rising global temperatures, it is feared, could pry open these refrigerated vaults.
With warming, oxygen and microbes could make their way into the carbon bank, where they would rot the well-conserved biomass like compost, converting some of it into carbon dioxide and a lot of it into methane, a greenhouse gas 30 to 50 times more potent than CO2.
Analogous to the bog monster’s resurrection, the gases would rise into the atmosphere with possibly disastrous consequences.
Research specialists from 19 universities are at Marcell studying multiple facets of this possible chain of events. Kostka is examining the final stages of the process.
“We’re understanding the below-ground carbon cycle and the microorganisms that are active in degrading the organic material,” Kostka said. Heightened activity would be a bad sign.
“If we found that a lot of that carbon at higher temperatures rose to the atmosphere as carbon dioxide and especially as methane — which traps more heat than carbon dioxide — then that would be a worst-case scenario,” he added.
In the worst case, imagining climate change as a wildfire, boreal peat bogs would be like gas stations or oil refineries in its path. Their particularly rich fuel stores would blast up global warming as the heat tapped into them.
Space station charm
The SPRUCE experiment, coordinated by the Department of Energy’s Oak Ridge National Laboratory (ORNL) and the Department of Agriculture’s Forest Service, is trying to see what it would take to set the deep carbon off. If it doesn’t exactly erupt into methane, what will happen? In the best case, will the bog just continue to suck up carbon gases from the atmosphere as it always has?
With such questions in mind, ORNL designed and built the warming laboratory that sprawls into the bog like a space station — and shares the same sterile charm.
Grated boardwalks of gray plastic supported by silvery metal posts branch out at right angles to 17 plots, where they encircle small orchestras of scientific instruments.
Football-sized cylinders hang from poles and girders, and bottomless pots and tubs are embedded in the Sphagnum. Most of these devices measure some variation of carbon in gas emissions or in the water.
“This big cylinder is for measuring the greenhouse gases,” Kostka said. “Right now you can see there’s a cover on top of it. And what the cover does is trap the gas inside the cylinder.”
But nature is the passenger on this journey, and the researchers take meticulous measures to ensure it is undisturbed, aside from the warming, so it can be studied in an authentic state.
Amongst the metal and plastic, rhododendrons dance diagonally over the shaggy moss, and cotton grass shoots straight up a foot or two, bursting into cotton-ball blossoms. Above them, tamarack and spruce tower alongside a weather scaffold.
Make mine hot
Most of the plots at SPRUCE have underground heating elements, and most are also enclosed in semi-transparent greenhouses as tall as the treetops inside them.
Above the door to one enclosure hangs a sign reading, “Welcome to a warmer future. +6.75° C, elevated CO2.” (That +6.75 Celsius would be +12.15° in Fahrenheit.)
Another reads +2.25° C and no elevated CO2; yet another reads +4.50° C, elevated CO2. The enclosures range from no additional heat or carbon dioxide all the way up to +9° C and added CO2 — a really extreme scenario that probably wouldn’t play out on Earth for at least 100 years.
Vents blast warm air into the enclosures, none of which have roofs, which allows the heat to waft out, on purpose.
“The open top is really so the gases and the precipitation can exchange within the chamber. We didn’t want a closed top chamber like an aquarium,” said Randy Kolka, a scientist with the Forest Service.
The idea is not to isolate the plots, but to have them participate in the natural weather of their surroundings, while riding a few degrees above it.
“There comes more rain,” Kostka says, as the precipitation dampens everyone in the enclosure.
The natural exchange goes for the water table, too. The enclosure allows natural ebbs and flows, and monitors them for traces of old carbon.
Right off the bog are three semi-truck-sized tanks; one holds propane for heat, the others hold CO2.
Watching grass grow
John Latimer has been watching grass grow for more than 33 years. And the leaves change color in the fall. And the flowers bloom in spring.
All along, he has kept records on the changing seasons. And all along, he has shared his observations with area residents on Tuesday mornings on radio station KAXE, 91.7 FM, Grand Rapids (Minnesota). He’s a local phenologist — someone who studies flora’s seasonal states. He also works for SPRUCE.
In the warmest chamber, at +9° Celsius, Latimer pokes a small camera on a long pole down a hole, then pulls it out slowly, snapping pictures of root systems to observe what warming might do to them.
“Once a week I come in and put the camera in,” he says. “I get the same pictures each week.” Over time, researchers will compare the shots to assess root development.
A hypothesis holds that greater warmth and carbon gases will make some plants grow faster and larger, altering the ecosystem and the water table. That could expose the carbon-rich peat deposits to more oxygen and promote their breakdown.
“At the end of the day — one day — I will have taken about 2,250 pictures,” Latimer said, grinning through a neatly groomed white beard. “Roots. Yep.”
He points to a plant that looks like a short, sparse fern with long, broad leaves. “Three-leaved false Solomon’s seal is the common name,” he said. It’s no giant, but it puts down the deepest roots in the plot.
The underground heating has been going on for a year, the above ground heating for a few months. But already Latimer has seen a whiplash in the local weather severely damage the tamarack trees in the +9° C chamber.
In early March, outdoor temperatures shot up to over 80° F. This heat, plus the additional 9° C (equivalent to 16° F), bumped the heat inside the chamber to nearly 100° F.
The plants, including the tamaracks, popped out new buds and sprigs as though spring had arrived.
Latimer thought he was seeing his second earliest spring on record, the earliest being 2012. “I had Aspens flowering. I had silver maple flowering. They were early in terms of all the records I have,” he said.
Then in mid-March, winter roared back, and buds dropped to the ground. The tamaracks turned brown, and the seasoned phenologist did a double-take. “Everything stopped moving,” Latimer said.
Of all the years he has notes on, he feels recent ones have been more extreme. Previously, the earliest and latest springs he had recorded were nine years apart, but that has changed.
“My bookends, my range, went from 1987 to 1996, and now it’s 2012 to 2013, earliest and latest ever. It’s astonishing. How do you get two years like that back-to-back that are absolutely the extremes?”
About that monster
Reports of record-breaking heat have become common with average global temperatures on the rise. February through April of this year in the bogs were the warmest such period on record.
But the big question for SPRUCE remains: Do scientists know yet if the methane catastrophe really will happen?
“Maybe, maybe not,” said Paul Hanson from ORNL, which is overseeing the experiment. He is its project coordinator. “The warming effects, depending on how big they are, have the potential to do good things for vegetative systems or to push things over the edge.”
It’s too early to tell. Scientists are giving SPRUCE 10 more years to come up with a meaningful glimpse at a warmed future.
Bad, good, bad news
But with the experiment barely fully cranked, there has already been some good news and some bad news. First, the good news.
So far, the gases and water coming out of the bog are not infused with carbon from those deep stores. That old carbon can be recognized by its percentage of radioactive carbon 14, which is different from current atmospheric carbon.
But the bad news is, Kolka from the Forest Service thinks that will change. “I do think you’re going to see the signal of that old carbon pretty soon,” he said.
Furthermore, warmed bog plots are already emitting more methane than usual even without tapping that deep, old peat, and the implications of that go beyond boreal bogs into the wider world.
“Just that release of methane supports the hypothesis that in a warming world, microbes will become more active,” Georgia Tech’s Kostka said. “And especially microbes that produce methane will become more active and release more methane.”
The microbes are called methanogens — a potential carbon gas monster, with or without any bog.
A huge pulse
There’s more. At Kostka’s lab in Atlanta, when he and his postdoctoral assistant, Max Kolton, warmed up moss samples, methane came streaming out. Kostka thinks he’ll see the same at SPRUCE with the addition of air heating.
“We expect this summer we’re going to see a huge pulse,” he said.
About 500 feet from SPRUCE, Kostka and Kolton slosh into open peatland to take core samples of deep peat. Their rubber boots mush a few inches into the moss carpet, as water rises to their insteps.
But that’s as far as they sink. The bogs offer as much support for walking as a foam mattress. The water is about 39° F; the air temperature, in mid-May, is about 45° F, but mosquitoes are undeterred by the chill and buzz by the dozens around the researchers’ mosquito-net head coverings.
Kostka talks about a counterpart to methanogens in the Sphagnum — methanotrophs. Methanotrophs eat methane and could possibly soften a methane boost. Over the millennia they have helped the moss build the carbon stores.
Kolton grunts and pulls out a corer full of deep peat. Kostka points to a layer. “You can see some of the ancient peat. It’s at least about 5,000 years old, maybe 8,000 years.”
It’s from either the time the city of Troy was founded or the beginning of the Copper Age. The deepest peat formed during the New Stone Age, when the Earth’s human population was about five million.
Ten years from now, SPRUCE scientists hope to know more about what the modern age’s place will be in the next layer of peat, and in all those past.
Ben Brumfield is a senior science writer with Georgia Tech’s Institute Communications. He is a former CNN.com editor