Skip to main content

Next global warming worry: Thawing tundra

By Natalie Boelman, Special to CNN
updated 11:25 PM EDT, Tue September 25, 2012
Researcher Shannan Sweet working in the Alaskan tundra in summer. Natalie Boelman says thawing of the tundra could release vast amounts of carbon dioxide and methane into the atmosphere.
Researcher Shannan Sweet working in the Alaskan tundra in summer. Natalie Boelman says thawing of the tundra could release vast amounts of carbon dioxide and methane into the atmosphere.
STORY HIGHLIGHTS
  • Natalie Boelman: Arctic sea at lowest extent recorded, affecting Earth's ability to cool
  • But, she says, change to sea's neighboring tundra ecosystem is also a big global-warming worry
  • The tundra locks up carbon in frozen soils; when they thaw, huge amounts released
  • Boelman: Tundra also a vast habitat; thawing will have far-reaching effects around globe

Editor's note: Natalie Boelman is an assistant research professor at the Lamont-Doherty Earth Observatory of Columbia University, New York. For the past 10 years she has been conducting field research on the impact of climate change on the North Slope of Alaska.

(CNN) -- A week ago Sunday, Arctic sea ice cover reached its lowest extent ever recorded. For good reason, there has been significant media focus on how a warming sea gobbles up the ice that is polar bear habitat and reduces the area's capacity to reflect the sun's rays. This is roughly equivalent to unplugging one pole's worth of the Earth's central air conditioning system.

But far less attention has been placed on what a naked Arctic Ocean means for its closest neighboring ecosystem: the Arctic tundra.

Beyond the images of icebergs and stranded polar bears, I doubt many people picture the Arctic's vast carpet of lush green plants, chirping songbirds or highs in the mid-70s -- all of which are typical of summertime on the tundra. With climate changing at an alarming rate and sea ice extent slipping away, the tundra stands to change a lot, and this, too, will affect the rest of the planet. It is time to start familiarizing ourselves with the tundra, and here's why.

Natalie Boelman
Natalie Boelman

The tundra biome is huge, covering 15% more of the Earth's surface than all 50 U.S. states combined. Currently, it stores a significant proportion of the Earth's carbon in its permanently frozen soils, keeping it locked away and unable to contribute to the atmosphere's giant pool of greenhouse gases.

Opinion: Why we should look to the Arctic

However, in much the same way that other bodies of water keep coastal cities such as San Francisco from having extremely cold winters and scorching hot summers, sea ice conditions in the Arctic Ocean influence weather patterns over the nearby tundra. Less sea ice is associated with warmer and drier summer conditions on the tundra. Consistently balmier summers will cause soils to warm and thaw to greater depths, unleashing long-stored carbon into the atmosphere in the form of carbon dioxide and methane, both of which are potent greenhouse gases.

The previous record low in Arctic Ocean ice cover occurred in 2007, and the hot, dry summer that accompanied it on the Alaskan tundra was highlighted by the largest, longest lasting and most severe tundra fire to burn in northern Alaska in recorded history. The fire covered an area roughly 10% larger than Manhattan and burned for 2½ months.

Robert Muller on global warming
Climate skeptic says global warming real

Although lightning frequently strikes the tundra, the landscape is typically fairly moist and so rarely ignites, and even when it does, the flames don't spread very far, burn very deeply or remain alight for very long. But the tundra was very dry in 2007 and fire-fueling winds kicked up the blaze. During this single event, the immediate combustion of plants and soils and the thawing of frozen soils injected an enormous amount of carbon into the atmosphere — an amount equivalent to what the entire tundra biome typically absorbs from the atmosphere through plant growth every year.

The effect of diminishing sea ice isn't limited to increasing atmospheric greenhouse gas concentrations. Warmer conditions on the tundra trigger a cascade of change, including converting its lush but short green carpet into a taller shag, since warmer soils and deeper thaw enable taller, woody plants to grow and thrive on the tundra. What my colleagues and I are discovering from our own work in Alaskan tundra is that this shift in vegetation cover has implications -- some good, some bad -- for the animals that depend on it for food and shelter.

Opinion: Extreme weather and a changing climate

Each spring many species of migratory songbirds travel to the Arctic tundra from all over the world to breed. Some nest in patches of tall vegetation and may stand to benefit from the expanding taller shag, but those that nest in short vegetation may not be able to adapt. What may likely benefit all species is that the taller vegetation harbors significantly more bugs to eat. We don't yet know which species will benefit, and which will suffer in response to the changes, but because each species plays a specific ecological role on the tundra, the downfall of one species or proliferation of another could have a domino effect that disrupts the tundra's delicate food web.

And in case you thought that what happens on the tundra stays on the tundra, consider that many of the sparrows, robins and warblers that visit our backyards in winter, or pass through come fall and spring, spend their summers breeding on the tundra; so, whatever happens to them there will affect which ones and how many of them show up at your bird feeder in the future, potentially setting off a local domino effect.

Since the Arctic as a whole is responding to climate change earlier and more acutely than the rest of the planet, we should think of it as an early warning system -- a proverbial canary in a coalmine. Perhaps if we pay closer attention to how the tundra is changing, we can learn some practical lessons on what types of changes to expect here at lower latitudes, which would enable us to mitigate the consequences, or at least plan for how to cope with them.

Follow us on Twitter @CNNOpinion

Join us on Facebook/CNNOpinion

The opinions expressed in this commentary are solely those of Natalie Boelman.

ADVERTISEMENT
Part of complete coverage on
updated 9:42 PM EST, Fri December 19, 2014
Conservatives know easing the trade embargo with Cuba is good for America. They should just admit it, says Fareed Zakaria.
updated 8:12 PM EST, Fri December 19, 2014
We're a world away from Pakistan in geography, but not in sentiment, writes Donna Brazile.
updated 12:09 PM EST, Fri December 19, 2014
How about a world where we have murderers but no murders? The police still chase down criminals who commit murder, we have trials and justice is handed out...but no one dies.
updated 6:45 PM EST, Thu December 18, 2014
The U.S. must respond to North Korea's alleged hacking of Sony, says Christian Whiton. Failing to do so will only embolden it.
updated 4:34 PM EST, Fri December 19, 2014
President Obama has been flexing his executive muscles lately despite Democrat's losses, writes Gloria Borger
updated 2:51 PM EST, Thu December 18, 2014
Jeff Yang says the film industry's surrender will have lasting implications.
updated 4:13 PM EST, Thu December 18, 2014
Newt Gingrich: No one should underestimate the historic importance of the collapse of American defenses in the Sony Pictures attack.
updated 7:55 AM EST, Wed December 10, 2014
Dean Obeidallah asks how the genuine Stephen Colbert will do, compared to "Stephen Colbert"
updated 12:34 PM EST, Thu December 18, 2014
Some GOP politicians want drug tests for welfare recipients; Eric Liu says bailed-out execs should get equal treatment
updated 8:42 AM EST, Thu December 18, 2014
Louis Perez: Obama introduced a long-absent element of lucidity into U.S. policy on Cuba.
updated 12:40 PM EST, Tue December 16, 2014
The slaughter of more than 130 children by the Pakistani Taliban may prove as pivotal to Pakistan's security policy as the 9/11 attacks were for the U.S., says Peter Bergen.
updated 11:00 AM EST, Wed December 17, 2014
The Internet is an online extension of our own neighborhoods. It's time for us to take their protection just as seriously, says Arun Vishwanath.
updated 4:54 PM EST, Tue December 16, 2014
Gayle Lemmon says we must speak out for the right of children to education -- and peace
updated 5:23 AM EST, Wed December 17, 2014
Russia's economic woes just seem to be getting worse. How will President Vladimir Putin respond? Frida Ghitis gives her take.
updated 1:39 AM EST, Wed December 17, 2014
Australia has generally seen itself as detached from the threat of terrorism. The hostage incident this week may change that, writes Max Barry.
updated 3:20 PM EST, Fri December 12, 2014
Thomas Maier says the trove of letters the Kennedy family has tried to guard from public view gives insight into the Kennedy legacy and the history of era.
updated 9:56 AM EST, Mon December 15, 2014
Will Congress reform the CIA? It's probably best not to expect much from Washington. This is not the 1970s, and the chances for substantive reform are not good.
updated 4:01 PM EST, Mon December 15, 2014
From superstorms to droughts, not a week goes by without a major disruption somewhere in the U.S. But with the right planning, natural disasters don't have to be devastating.
updated 9:53 AM EST, Mon December 15, 2014
Would you rather be sexy or smart? Carol Costello says she hates this dumb question.
updated 5:53 PM EST, Sun December 14, 2014
A story about Pope Francis allegedly saying animals can go to heaven went viral late last week. The problem is that it wasn't true. Heidi Schlumpf looks at the discussion.
updated 10:50 AM EST, Sun December 14, 2014
Democratic leaders should wake up to the reality that the party's path to electoral power runs through the streets, where part of the party's base has been marching for months, says Errol Louis
updated 4:23 PM EST, Sat December 13, 2014
David Gergen: John Brennan deserves a national salute for his efforts to put the report about the CIA in perspective
updated 9:26 AM EST, Fri December 12, 2014
Anwar Sanders says that in some ways, cops and protesters are on the same side
updated 9:39 AM EST, Thu December 11, 2014
A view by Samir Naji, a Yemeni who was accused of serving in Osama bin Laden's security detail and imprisoned for nearly 13 years without charge in Guantanamo Bay
updated 12:38 PM EST, Sun December 14, 2014
S.E. Cupp asks: How much reality do you really want in your escapist TV fare?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT