How Melting Antarctic Ice Could Help Fight Climate Change

How Melting Antarctic Ice Could Help Fight Climate Change

Furious winds keep the McMurdo Dry Valleys in Anarctica free of snow and ice. Calcites found in the valleys have revealed the secrets of ancient subglacial volcanoes. Stuart Rankin/Flickr, CC BY-NC

Iron is not commonly famous for its role as a micronutrient for tiny organisms dwelling in the cold waters of polar oceans. But iron feeds plankton, which in turn hold carbon dioxide in their bodies. When they die, the creatures sink to the bottom of the sea, safely storing that carbon.

How exactly the iron gets to the Southern Ocean is hotly debated, but we do know that during the last ice age huge amounts of carbon were stored at the bottom of the Southern Ocean. Understanding how carbon comes to be stored in the depth of the oceans could help abate CO2 in the atmosphere, and Antarctica has a powerful role.

Icebergs and atmospheric dust are believed to have been the major sources of this micronutrient in the past. However, in research published in Nature Communications, my colleagues and I examined calcite crusts from Antarctica, and found that volcanoes under its glaciers were vital in delivering iron to the ocean during the last ice age.

Today, glacial meltwaters from Greenland and the Antarctic peninsula supply iron both in solution and as tiny particles (less than 0.0001mm in diameter), which are readily consumed by plankton. Where glaciers meet bedrock, minute organisms can live in pockets of relatively warm water. They are able to extract “food” from the rock, and in doing so release iron, which then can be carried by underwater rivers to the sea.

Volcanic eruptions under the ice can create underwater subglacial lakes, which, at times, discharge downstream large masses of water that travel to the ice margin and beyond, carrying with them iron in particle and in solution.

The role of melting ice in climate change is as yet poorly understood. It’s particularly pertinent as scientists predict the imminent collapse of part of the Larsen C ice shelf.

Researchers are also investigating how to reproduce natural iron fertilisation in the Southern Ocean and induce algal blooms. By interrogating the volcanic archive, we learn more about the effect that iron fertilisation from meltwater has on global temperatures.

The Last Glacial Maximum

During the Last Glacial Maximum, a period 27,000 to 17,000 years ago when glaciers were at their greatest extent worldwide, the amount of CO2 in the atmosphere was lowered to 180 parts per million (ppm) relative to pre-industrial levels (280 ppm).

Today we are at 400 ppm and, if current warming trends continue, a point of no return will be reached. The global temperature system will return to the age of the dinosaurs, when there was little difference in temperature from the equator to the poles.

If we are interested in providing a habitable planet for our descendants, we need to mitigate the quantity of carbon in the atmosphere. Blooms of plankton in the Southern Ocean boosted by iron fertilisation were one important ingredient in lowering CO2 in the Last Glacial Maximum, and they could help us today.

The Last Glacial Maximum had winds that spread dust from deserts and icebergs carrying small particles into the Southern Ocean, providing the necessary iron for algal blooms. These extreme conditions don’t exist today.

Hidden volcanoes

Neither dust nor icebergs alone, however, explain bursts of productivity recorded in ocean sediments in the Last Glacial Maximum. There was another ingredient, only discovered in rare archives of subglacial processes that could be precisely dated to the Last Glacial Maximum.

Loss of ice in Antartica’s Dry Valleys uncovered rusty-red crusts of calcite plastered on glacially polished rocks. The calcites have tiny layers that can be precisely dated by radiometric techniques.

antarcticia2 6 24 A piece of subglacial calcite coating pebbles. This suggests that the current transporting the pebbles was quite fast, like a mountain stream. The pebbles were deposited at the same time as the opaque layer in the calcite formed. Supplied

Each layer preserves in its chemistry and DNA a record of processes that contributed to delivering iron to the Southern Ocean. For example, fluorine-rich spherules indicate that underwater vents created by volcanic activity injected a rich mixture of minerals into the subglacial environment. This was confirmed by DNA data, revealing a thriving community of thermophiles – microorganisms that live in very hot water only.

Then, it became plausible to hypothesise that volcanic eruptions occurred subglacially and formed a subglacial lake, whose waters ran into an interconnected system of channels, ultimately reaching the ice margin. Meltwater drained iron from pockets created where ice met bedrock, which then reached the ocean – thus inducing algal blooms.

We dated this drainage activity to a period when dust flux does not match ocean productivity. Thus, our study indicates that volcanoes in Antarctica had a role in delivering iron to the Southern Ocean, and potentially contributed to lowering CO2 levels in the atmosphere.

The ConversationOur research helps explain how volcanoes act on climate change. But it also uncovers more about iron fertilisation as a possible way to mitigate global warming.

About The Author

Silvia Frisia, Associate Professor, School of Environmental and Life Sciences , University of Newcastle

This article was originally published on The Conversation. Read the original article.

Related Books:

List Price: $17.99
Sale Price: $17.99 $14.49 You save: $3.50


List Price: $22.95
Sale Price: $22.95 $18.67 You save: $4.28


List Price: $7.99
Sale Price: $7.99 $6.21 You save: $1.78


enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook-icontwitter-iconrss-icon

 Get The Latest By Email

{emailcloak=off}

EVIDENCE

How Climate Change Affects Wildfires
by NBC News
NYU environmental studies professor David Kanter explains how climate change is creating the perfect conditions for…
Warning of 'Untold Human Suffering,' Over 11,000 Scientists From Around the World Declare Climate Emergency
Warning of Untold Human Suffering, Over 11,000 Scientists From Around the World Declare Climate Emergency
by Julia Conley
"Scientists have a culture of reticence when it comes to making statements like this, but the emergency is rapidly…
New Land Height Metric Raises Sea Level Rise Risk
New Land Height Metric Raises Sea Level Rise Risk
by Tim Radford
Millions of us now live in danger: we could be at risk from future high tides and winds, says a new approach to…
The Science Of Drought Is Complex But The Message On Climate Change Is Clear
The Science Of Drought Is Complex But The Message On Climate Change Is Clear
by Ben Henley, et al
The issue of whether Australia’s current drought is caused by climate change has been seized on by some media…
Understanding Natural Climate Cycles
by NOVA PBS
The climate has changed on a schedule for millennia.
"Climate Predictions and Projections" by Jim Hurrell (Climate Change Symposium)
by Jim Hurrell
Professor Jim Hurrell presents "Climate Predictions and Projections in the Coming Decades: Uncertainty due to Natural…
Understanding Climate Change Science On Oceans And The Cryosphere
by CBC Nova Scotia
The United Nations panel dedicated to reviewing the science of climate change recently released a dense new report…
Where's The Proof In Science?
Where's The Proof In Science?
by Geraint Lewis
One word is rarely spoken or printed in science and that word is “proof”. In fact, science has little to do with…

LATEST VIDEOS

300 Million Face Severe Risk of Climate-Fueled Coastal Flooding by 2050
by Democracy Now!
As a shocking new report finds that many coastal cities will be flooded by rising sea levels by 2050, Chile’s President…
Climate Warning: California Continues To Burn, Data Estimates Of Global Flooding
by MSNBC
Ben Strauss, CEO and Chief Scientist of Climate Central joins MTP Daily to discuss alarming new information about…
Stanford Climate Solutions
by Stanford
Climate change has brought us to a defining moment in human history.
Buying Renewable Energy From Your Neighbor
by NBC News
Brooklyn Microgrid, a project of parent company LO3 Energy, is looking to disrupt the more than 100-year-old energy…
Debate Over Pipelines Clouds Concern For Climate Change
by Global News
Climate experts are warning that Canada shouldn't ignore the wildfire crisis in California
How Climate Change Affects Wildfires
by NBC News
NYU environmental studies professor David Kanter explains how climate change is creating the perfect conditions for…
Rice Bowl Of Malaysia Threatened By Climate Change
by The Star Online
Kedah is known as the country’s “Rice Bowl,” and it is especially suitable for the growing of the grain.
Maine Cow's Seaweed Diet Research Could Help Climate Change
by News Center Maine
Research in Maine will measure the methane released by cows who have been fed a seaweed diet.

LATEST ARTICLES

Why The Global Climate Treaty Is Not Working
Why The Global Climate Treaty Is Not Working
by Tim Radford
Three out of four nations have yet to start to honour the global climate treaty. The world waits, the seas go on rising…
Why Taxes Are Better Than Bans For Keeping Homeowners From Rebuilding In Fire-plagued Areas
Why Taxes Are Better Than Bans For Keeping Homeowners From Rebuilding In Fire-plagued Areas
by Alexander Smith
Almost 200,000 Californians have been ordered to evacuate as ferocious winds drove several wildfires near Los Angeles,…
How Will 20 Years Of Houston’s Growth Affect Flooding?
How Will 20 Years Of Houston’s Growth Affect Flooding?
by InnerSelf Staff
A new way to show exactly how much the city of Houston has changed in the last two decades gives a dramatic visual…
Why Australia Could Fall Apart Under Climate Change
Why Australia Could Fall Apart Under Climate Change
by Ross Garnaut
Four years ago in December 2015, every member of the United Nations met in Paris and agreed to hold global temperature…
How Greenhouse Gases Drive Australia's Bushfires
How Greenhouse Gases Drive Australia's Bushfires
by Andrew Burgess
Australia’s bushfires are feeding on heat from the climate change happening in the tropics, but its government doesn’t…
How Children Born Now Face Multiple Climate Health Risks
How Children Born Now Face Multiple Climate Health Risks
by Tim Radford
Multiple climate health risks threaten today’s babies. They may grow up hungrier, more diseased and facing more…
This Is What Australia's Growing Cities Need To Do To Avoid Running Dry
This Is What Australia's Growing Cities Need To Do To Avoid Running Dry
by Ian Wright
The increasing thirst of Australia’s biggest cities routinely exceeds our capacity to rely on rainfall for drinking…
Evangelicals In Brazil See Abuse Of God's Earth As A Sin – But Will They Fight To Save The Amazon?
Evangelicals In Brazil See Abuse Of God's Earth As A Sin – But Will They Fight To Save The Amazon?
by Amy Erica Smith
When the Brazilian city of São Paulo abruptly went dark at midday on Aug. 19, there was talk of the Apocalypse – not…