Strange Bedfellows in the Climate Change Saga: Taiga to Tundra
By Shahid Naeem, PhD
Earth Institute Center for Environmental Sustainability and the Department of Ecology, Evolution, and Environmental Biology
Taiga to tundra
In the nine-hour drive on the great Dalton Highway to Toolik Field Station one starts out in the boreal forest, which is also called the “taiga,” but the forest eventually disappears. More accurately, trees disappear. Leaving Fairbanks, one drives through beautiful stands of spruce, birch, and aspen trees, but as one gets closer and closer to the Brooks Range, a beautiful mountain range one has to cross to get to the tundra, the climate gets colder, the permafrost builds, and the forest begins to disappear.
“Permafrost” is a funny term. It’s soil that remains frozen year round, but there is nothing necessarily permanent about it. In fact, if the soil is frozen continuously for just two years it qualifies for being permafrost. Most permafrost, is, of course, frozen for very long times and can be quite deep. In the Northern Hemisphere, permafrost can range from a few feet to over 4,500 feet deep and range in age from less than a century to over tens of thousands of years old. There is also a lot of permafrost – almost a quarter of the Northern Hemisphere is variably covered with it. That’s a lot of frozen, inactive soil. A sleeping giant rich in carbon.
The shallow soils above the permafrost don’t provide much support for trees and occasionally one passes what are called “drunken forests” because the spruce trees tilt in different angles since they cannot anchor themselves well to the ground. The trees get thinner and more scraggly and begin to disappear. In fact, the last spruce tree on the northward journey used to be at about 235 miles up the highway and was sign posted, but a vandal killed it. Once one is over the mountains, the tundra dominates and by the time one gets to mile 285, woody vegetation in the open tundra consists of tiny things like dwarf birch and willow shrubs that are often not much higher than one’s ankles. Shrubs are much taller when you get near streams or rivers, but basically the tundra is a treeless landscape.
It occurred to me that if we came across a wolf, which I wanted desperately to see, it would have few places to hide in the open tundra. I might even get a photo. Though we travelled considerable distances in the tundra during my short visit, there were no wolves to be found. I saw caribou in the distance, many species of birds, and few small mammals, but no wolves.
The real purpose of my trip, however, was to work with Natalie Boelman, a research scientist at Lamont-Doherty Earth Observatory and Kevin Griffin, a professor in Columbia University’s Department of Earth and Environmental Sciences. Natalie and Kevin are bio-climate-change scientists. Climate-change scientists come in many flavors – those who study geology, those who study physics and chemistry, and those who study biology. Biologically, the life processes important to climate are well known and Natalie and Kevin are leaders in the field. I was interested in the role biodiversity plays in bio-climate-change processes so Natalie and Kevin would be terrific collaborators to learn about the tundra. They studied birds, insects, shrubs and other vegetation, as well as photosynthesis and respiration to better understand how the tundra is changing under the influence of climate change.
The key processes in bio-climate-change involve plants, animals, and microorganisms capturing and releasing carbon. Plants capture carbon from the atmosphere by photosynthesis and this carbon is incorporated into the mass of living organisms in the ecosystem – not just the mass of plants, but the mass of all animals and microorganisms that feed or depend on the plants for their carbon. Eventually, as organisms die and microbes go to work, the captured carbon is stored as organic compounds in the tundra. If this captured carbon enters the permafrost, it could be stored away for thousands of years.
So long as less carbon is respired by the plants, animals, and microorganisms than carbon captured by photosynthesis, the carbon keeps building up in the soils and permafrost. It’s an interesting balance – too much photosynthesis, and carbon builds up in the ecosystem. Too much respiration, and the carbon disappears and the soils and ecosystem become unhealthy.
In fact, fossil fuels, such as the millions of barrels that course down the Trans Alaskan Pipeline every year or the gasoline in one’s car or the coal burning in a power plant, originated from the very same biological processes that govern the carbon cycle today. Ecosystems typically capture more carbon than they respire, so they build up biomass. Bury this biomass and let it stew under pressure and heat for tens of thousands to millions of years, and it becomes some form of fossil fuel. One doesn’t have to wait for biomass to turn into coal, natural gas, or oil to burn it – you can just burn the mass itself, as we do in our fireplaces. Whichever way one burns biomass, as biofuels or fossil fuels, we return the carbon to the atmosphere. We also don’t have to burn biomass to return carbon to the atmosphere – we can simply warm up an ecosystem or find some other way to make respiration greater than photosynthesis. The net result of all these activities, burning biofuels, burning fossil fuels, or warming an ecosystem, is the same – we shift the balance so that more carbon is entering the atmosphere than is being pulled out of it by photosynthesis. This is the core principle of bio-climate-change science.
The ticking Arctic carbon bomb
In preparation for the trip, I read many of the papers and reports that have emanated from the research at Toolik. Researchers from many universities and institutes, both in the United States and around the world, have documented dramatic changes in arctic ecosystems at Toolik. While I was there, I got to see some of this research firsthand and experience for myself the alarming story these studies collectively tell. The shocking story is that everything is changing. The abundance of spiders, insects, birds, mammals, all the plants, fish, and even microorganisms are all responding to the changes in temperature and precipitation caused by climate change. The chemistry of Arctic soils and its thousands of lakes, ponds, streams and rivers are also changing. All the world’s ecosystems are responding to climate change, but no ecosystem on Earth is changing as fast as those of the Arctic.
The changes are so many it’s hard to know precisely what is happening. The story is complex and while research is underway one can only give cautionary answers, but we have a good sense of what is going on. In the same way investigators in criminal cases restrict their comments in ongoing investigations, scientists prefer to wait till the investigations are relatively complete before giving precise answers. It is fairly clear, however, that the global thermostat, at least that part of it that resides in the Artic, is falling apart. The two trillion tons of carbon stored in Arctic soils may never fully return to the atmosphere, but so much of it could that climate change will be far worse than we imagined.
Eli Kintisch, a news reporter for Science magazine, refers to this as the “ticking Arctic carbon bomb.” The vast stores of carbon in the Arctic totaling close to two trillion tons could, in the next few decades, be released into the atmosphere, rivaling what humans put in from their burning of fossil fuels.
As the days sped by and the likelihood that I would see a wolf before I had to leave dwindled, I was struck by the great irony of the Alaskan region we were working in. The road serves both those in the oil industry that supply the fossil fuels we burn that is causing horrific changes in our world’s climate at the same time as it serves the arctic researchers, like those I was visiting, who are studying the awful impacts of climate change caused by fossil fuel burning. The Dalton Highway, once called the North Slope Haul Road, traces its origin to one of America’s greatest construction projects; the Trans Alaska Pipeline. Costing 8 billion dollars and spanning over 800 miles, the pipeline has carried over 16,698,123,887 barrels (a barrel = 44 gallons) of oil to tankers in Valdez, Alaska on the shore of Prince William Sound. Valdez was an otherwise obscure place until the Exxon Valdez ran aground in 1989 and spilled over a quarter million barrels of oil into the Sound. The spill polluted hundreds of miles of coastal ecosystems and killed an estimated quarter million birds, 2,800 sea otters, 300 harbor seals, and 250 bald eagles, America’s national bird. The loss of salmon and other marine life was incalculable, but massive. Though much, much smaller than the more recent Deepwater Horizon spill of five million barrels of oil in the Gulf of Mexico in 2006, its environmental damage was staggering. It’s not just how much oil you spill that matters as where you spill it.
The Exxon Valdez oil spill aside, the pipeline was an engineering miracle. It had to cross the mountains of the Brooks Range, endure washouts, slush flows, and avalanches and be built on the highly unstable permafrost that underlies the tundra. All this construction had to take place where it is dark half the year and the sun never sets for the other half. America’s coldest temperature on record, -80o F, was recorded at Prospect Creek, an Alaskan Pipeline camp.
All this to deliver 200-300 million barrels per year which, at about a $100 a barrel in today’s market, is worth about 20-30 billion dollars. Sounds like a lot, but it’s only three quarters of one percent of total global oil production which is roughly 32 billion barrels per year. From an economic perspective, consider that in 2011, a record year for oil revenue, the five major oil companies recorded 137 billion dollars in profits. It’s hard to wrap one’s head around these figures, but it does tell us that as massive and impressive as the Trans Alaskan Pipeline seems, by comparison the global oil industry is monstrously larger.
The saga of climate change
So there you have it – truckers working tirelessly to ensure the delivery of fossil fuels that are the root cause of climate change share the road with scientists studying climate change and tourists hoping to see Arctic ecosystems before climate change alters them irrevocably. Truckers and non-truckers, together on the Dalton Highway, strange bedfellows in the saga of climate change. It is an interesting twist that were it not for the great Dalton Highway built to serve the Alaskan Pipeline, the extraordinary arctic field station most likely would never have been built.
On the last night before my departure, sorry that I did not see a wolf, I considered that perhaps my passion for wildlife is not so misplaced and not something I should keep separate from my work as a scientist. Plants, animals, and microorganisms are critical to our survival and nowhere is this more crystal clear than in Arctic ecosystems. The biota of the Arctic is responsible for the huge stores of carbon that have been safely stored there for thousands of years. Most people will never see the tundra and will only know it as an exotic place up in the wintery Northern latitudes, yet as they feel the climate about them change, as the storms become stronger and more dangerous, as droughts, floods, and fires take increasing tolls on people around the world, they are connected to it. Whether it is Hurricane Sandy knocking out New York City, mile-wide tornadoes in Oklahoma City, record fires in Sydney Australia, or the millions of people facing drought in Sub-Saharan Africa, we are all connected to the bears, caribou, willows, moss, sedges, and soil microbes of the Arctic. By the same argument, we are all connected to the wolf.
As I was looking outside the window at the vast expanse of the tundra reaching all the way to the snowy Brooks Range gleaming in the distance, I realized that to see a wolf was not just an idle desire from a lover of wildlife. If I saw a wolf, it would mean the Arctic system was still intact, still working, still capable of doing its job of capturing more carbon than it respired, because top predators, like wolves, only persist if their ecosystem is working well. Predators are often seen as indicators of ecosystem health.
Then, as impossible as it might seem, a wolf came over the hill. Just as I was looking outside the window of the dining hall and realizing that to see a wolf was not just an fervent wish but a desire to see what would be a profoundly reassuring symbol of hope for the tundra, for biodiversity, and for our own survival and wellbeing in an age of Anthropogenic climate change, a wolf came over the hill. I pointed it out to my colleague and we and all the people in the hall went out quietly on the deck to see it. It did not see us, but it saw the many buildings and strange structures of the Toolik Field Station. It stopped, clearly puzzled by what it had come across, then decided it should avoid the Station. It turned and went back the way it came. I had my camera, which I always carry with me when doing biodiversity research, and managed to take a picture.