The Arctic is turning brown because of weird weather – and it could accelerate climate change

The Arctic is turning brown because of weird weather – and it could accelerate climate change

‘Brow-raising browning. Rachael Treharne, Author provided

Over the last few years Arctic scientists have reported a surprising finding: large areas of the Arctic are turning brown. This is in part due to extreme events linked to winter weather, such as sudden, short-lived periods of extreme warmth. These events are occurring as the climate warms, which is happening twice as fast in the Arctic compared with the rest of the planet. Extreme events are therefore happening more and more often, with increasingly severe effects – including widespread damage and death in Arctic plants.

This “browning” of plant communities has happened over thousands of square kilometres or more. However, until recently we knew very little about what this might mean for the balance between carbon uptake and release in Arctic ecosystems. Given that the Arctic stores twice as much carbon as the atmosphere, this is a pressing concern.

Now, our study has shown that extreme climatic events can significantly reduce the ability of Arctic ecosystems to take up carbon –- with implications for whether the Arctic will help combat climate change, or accelerate it.

The Arctic is turning brown because of weird weather – and it could accelerate climate change Dead and brown vegetation on a heathland in Norway. Rachael Treharne, Author provided

The carbon cost of extreme weather

To understand how extreme events are affecting Arctic heathlands, we travelled to the Lofoten Islands in northern Norway where coastal, sub-Arctic plant communities act as a bellwether for future climate change in the far north by exhibiting the effects of warming in the region first.

Here we found the effects of two extreme winter weather events. First, “frost drought” had caused extensive plant dieback. Frost drought occurs when the insulating layer of snow which usually protects plants from the harsh Arctic winter is melted, typically by unusually high winter temperatures. If plants remain exposed to cold, windy conditions for long enough, they continually lose water and are unable to replace it from the frozen soil. Eventually, they succumb to drought.

The second event was “extreme winter warming” – a sudden burst of high temperatures during winter which melts the snow and tricks evergreen plants into preparing for spring by shedding their cold tolerance. When the warm period is over, the return of cold temperatures usually kills the plant. In this case, however, we found something unexpected. Heathland plants had survived this extreme winter warming event, but were showing evidence of severe stress, visible as a deep, persistent dark red colour in shoots and leaves.

The Arctic is turning brown because of weird weather – and it could accelerate climate change Deep red pigmentation indicates that this plant is under stress from the unpredictable climate. Rachael Treharne, Author provided

We measured how much carbon dioxide was being taken in and released by the plants in three vegetation types: damaged heathland (where the dominant evergreen species had been killed by frost drought), stressed heathland, and healthy, green heathland which had escaped the effects of either extreme event. This was done in three measurement periods across the growing season.

We found that these extreme winter conditions reduced how much carbon was absorbed in heathland ecosystems by up to 50% across the entire growing season. This is a huge reduction in the ability of a widespread Arctic ecosystem to remove carbon from the atmosphere.

Surprisingly, this was the case both in damaged heathland, where a large part of the vegetation had been killed, and in stressed heathland. Although the processes driving this change were different in each type of heathland, this clearly shows that we need to consider the role of plant stress in limiting plant carbon uptake to fully appreciate the consequences of extreme climatic events.

The Great Brown North

What does this mean for the Arctic? We now know that extreme climatic events could significantly reduce the ability of Arctic ecosystems to take up carbon and combat climate change.

This is especially concerning as the impacts of browning are in stark contrast to those of a better understood response of Arctic ecosystems to climate change: “Arctic greening”, or the tendency for plants to become taller and more productive as Arctic summers warm.

The Arctic is turning brown because of weird weather – and it could accelerate climate change Instruments measuring carbon uptake and release at the test site. Rachael Treharne, Author provided

Many climate models currently assume arbitrary levels of greening across the Arctic, and therefore that Arctic ecosystems will take up more carbon in the future – slowing climate change. The scale of the browning we’ve seen in recent years combined with the negative impacts on carbon uptake reported here suggests that the reality may be more complex, calling into question our understanding of the role of the Arctic in the Earth’s climate.

What does this mean for us? The impact of extreme weather events in the Arctic has global consequences. It is clear that our current efforts to tackle climate change are dangerously inadequate, but ambitious action now could cut how much the Arctic is expected to warm by as much as 7°C. This is critical to minimising the impacts of climate change both in Arctic ecosystems and worldwide.The Conversation

About The Author

Rachael Treharne, PhD Researcher in Arctic Ecology, University of Sheffield

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Related Books

InnerSelf Market

Amazon

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook icontwitter iconyoutube iconinstagram iconpintrest iconrss icon

 Get The Latest By Email

Weekly Magazine Daily Inspiration

LATEST VIDEOS

The Great Climate Migration Has Begun
The Great Climate Migration Has Begun
by Super User
The climate crisis is forcing thousands around the world to flee as their homes become increasingly uninhabitable.
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
by Alan N Williams, et al
The latest report from the Intergovernmental Panel on Climate Change (IPCC) states that without a substantial decrease…
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
by Toby Tyrrell
It took evolution 3 or 4 billion years to produce Homo sapiens. If the climate had completely failed just once in that…
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
by Brice Rea
The end of the last ice age, around 12,000 years ago, was characterised by a final cold phase called the Younger Dryas.…
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
by Frank Wesselingh and Matteo Lattuada
Imagine you are on the coast, looking out to sea. In front of you lies 100 metres of barren sand that looks like a…
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
by Richard Ernst
We can learn a lot about climate change from Venus, our sister planet. Venus currently has a surface temperature of…
Five Climate Disbeliefs: A Crash Course In Climate Misinformation
The Five Climate Disbeliefs: A Crash Course In Climate Misinformation
by John Cook
This video is a crash course in climate misinformation, summarizing the key arguments used to cast doubt on the reality…
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
by Julie Brigham-Grette and Steve Petsch
Every year, sea ice cover in the Arctic Ocean shrinks to a low point in mid-September. This year it measures just 1.44…

LATEST ARTICLES

3 wildfire lessons for forest towns as Dixie Fire destroys historic Greenville, California
3 wildfire lessons for forest towns as Dixie Fire destroys historic Greenville, California
by Bart Johnson, Professor of Landscape Architecture, University of Oregon
A wildfire burning in hot, dry mountain forest swept through the Gold Rush town of Greenville, California, on Aug. 4,…
China Can Meet Energy and Climate Goals Capping Coal Power
China Can Meet Energy and Climate Goals Capping Coal Power
by Alvin Lin
At the Leader’s Climate Summit in April, Xi Jinping pledged that China will “strictly control coal-fired power…
Blue water surrounded by dead white grass
Map tracks 30 years of extreme snowmelt across US
by Mikayla Mace-Arizona
A new map of extreme snowmelt events over the last 30 years clarifies the processes that drive rapid melting.
A plane drops red fire retardant on to a forest fire as firefighters parked along a road look up into the orange sky
Model predicts 10-year burst of wildfire, then gradual decline
by Hannah Hickey-U. Washington
A look at the long-term future of wildfires predicts an initial roughly decade-long burst of wildfire activity,…
White sea ice in blue water with the sun setting reflected in the water
Earth’s frozen areas are shrinking 33K square miles a year
by Texas A&M University
The Earth’s cryosphere is shrinking by 33,000 square miles (87,000 square kilometers) per year.
A row of male and female speakers at microphones
234 scientists read 14,000+ research papers to write the upcoming IPCC climate report
by Stephanie Spera, Assistant Professor of Geography and the Environment, University of Richmond
This week, hundreds of scientists from around the world are finalizing a report that assesses the state of the global…
A brown weasel with a white belly leans on a rock and looks over its shoulder
Once common weasels are doing a vanishing act
by Laura Oleniacz - NC State
Three species of weasels, once common in North America, are likely in decline, including a species that’s considered…
Flood risk will rise as climate heat intensifies
by Tim Radford
A warmer world will be a wetter one. Ever more people will face a higher flood risk as rivers rise and city streets…

 Get The Latest By Email

Weekly Magazine Daily Inspiration

New Attitudes - New Possibilities

InnerSelf.comClimateImpactNews.com | InnerPower.net
MightyNatural.com | WholisticPolitics.com | InnerSelf Market
Copyright ©1985 - 2021 InnerSelf Publications. All Rights Reserved.