7 Ways To To Suck CO₂ Out Of The Atmosphere

7 Ways To To Suck CO₂ Out Of The AtmosphereShutterstock

Australian Federal Energy Minister Angus Taylor is on Tuesday. September 22, 2020 expected to outline the Morrison government’s first Low Emissions Technology Statement, plotting Australia’s way forward on climate action. It’s likely to include “negative emissions” technologies, which remove carbon dioxide (CO₂) from the air.

The Intergovernmental Panel on Climate Change says negative emissions technologies will be needed to meet the Paris Agreement goal of limiting warming to well below 2℃. In other words, just cutting emissions is not enough – we must also take existing greenhouse gases from the air.

Last week, the government broadened the remit of the Australian Renewable Energy Agency (ARENA) and the Clean Energy Finance Corporation (CEFC). It flagged negative emissions technologies, such as soil carbon, as one avenue for investment.

Some negative emissions ventures are operating in Australia at a small scale, including carbon capture, reforestation and soil carbon management. Here, we examine seven ways to remove CO₂ from the atmosphere, including their pros and cons.

Graphic showing seven negative emissions technologies. (seven ways to to suck co2 out of the atmosphere)Graphic showing seven negative emissions technologies. Anders Claassens

1. Managing soil carbon

Up to 150 billion tonnes of soil carbon has been lost globally since farming began to replace natural forests and grasslands. Improved land management could store or “sequester” up to nine billion tonnes of CO₂ each year. It could also improve soil health.

Soil carbon can be built through methods such as:

  • no-till” farming, using techniques that don’t disturb soil
  • planting cover crops, which protect soil between normal cropping periods
  • grazing livestock on perennial pastures, which last longer than annual plants
  • applying lime to encourage plant growth
  • using compost and manure.

It’s important to remember though, that carbon can be hard to store in soils for long periods. This is because microbes consume organic matter, which releases carbon back to the atmosphere.

2. Biochar

Biochar is a charcoal-like material produced from organic matter such as green waste or straw. It is added to soil to boost carbon stores, by promoting microbial activity and aggregation (soil clumps) which prevents organic plant matter breaking down and releasing carbon.

Biochar has been used by indigenous people in the Amazon to increase food production. More than 14,000 biochar studies have been published since 2005. This includes work by Australian researchers showing how biochar reacts with soil minerals, microbes and plants to improve soil and stimulate plant growth.

On average, biochar increases crop yields by about 16% and halves emissions of nitrous oxide, a potent greenhouse gas. The production of biochar releases gases that can generate renewable heat and electricity. Research suggests that globally, biochar could store up to 4.6 billion tonnes of CO₂ each year.

However its potential depends on the availability of organic material and land on which to grow it. Also, the type of biochar used must be suitable for the site, or crop yields may fall.

Added to soil, biochar increases carbon stores.  (seven ways to to suck co2 out of the atmosphere)Added to soil, biochar increases carbon stores. Shutterstock

3. Reforestation

Planting trees is the simplest way to take CO₂ from the atmosphere. Reforestation is limited only by land availability and environmental constraints to growth.

Reforestation could sequester up to ten billion tonnes a year of CO₂. However, carbon sequestered through reforestation is vulnerable to loss. For example, last summer’s devastating bushfires released around 830 million tonnes CO₂.

4. Bioenergy with carbon capture and storage (BECCS)

Plant material can be burned for energy – known as bioenergy. In a BECCS system, the resulting CO₂ is captured and stored deep underground.

Currently, carbon capture and storage (CCS) is only viable at large scale, and opportunities for storage are limited. Only a few CCS facilities operate internationally.

BECCS has the potential to sequester 11 billion tonnes annually. But this is limited by availability of material to burn – which in theory could come from forestry and crop waste, and purpose-grown plants.

The large-scale deployment of CCS will also have to overcome barriers such as high costs, challenges in dealing with leaks, and determining who takes long-term responsibility for the stored carbon.

Bioenergy has big potential but is limited by the amount of material available to burn. (seven ways to to suck co2 out of the atmosphere)Bioenergy has big potential but is limited by the amount of material available to burn. Shutterstock

5. Enhanced weathering of rocks

Silicate rocks naturally capture and store CO₂ from the atmosphere when they weather due to rain and other natural processes. This capturing can be accelerated through “enhanced weathering” – crushing rock and spreading it on land.

The preferred rock type for this method is basalt – nutrient-rich and abundant in Australia and elsewhere. A recent study estimated enhanced weathering could store up to four billion tonnes of CO₂ globally each year.

However low rainfall in many parts of Australia limits the rate of carbon capture via basalt weathering.

6. Direct air carbon capture and storage (DACCS)

Direct air carbon capture and storage (DACCS) uses chemicals that bond to ambient air to remove CO₂. After capture, the CO₂ can be injected underground or used in products such as building materials and plastics.

DACCS is in early stages of commercialisation, with few plants operating globally. In theory, its potential is unlimited. However major barriers include high costs, and the large amount of energy needed to operate large fans required in the process.

7. Ocean fertilisation and alkalinisation

The ocean absorbs around nine billion tonnes of CO₂ from the air each year.

The uptake can be enhanced by fertilisation – adding iron to stimulate growth of marine algae, similar to reforestation on land. The ocean can also take up more CO₂ if we add alkaline materials, such as silicate minerals or lime.

However ocean fertilisation is seen as a risk to marine life, and will be challenging to regulate in international waters.

Looking ahead to a zero-carbon world

The foreshadowed government investment in negative emissions technologies is a positive step, and will help to overcome some of the challenges we’ve described. Each of the technologies we outlined has the potential to help mitigate climate change, and some offer additional benefits.

But all have limitations, and alone they will not solve the climate crisis. Deep emissions reduction across the economy will also be required.

Correction: a previous version of this article said biochar could store up to 4.6 million tonnes of CO₂ each year. The correct figure is 4.6 billion tonnes.

About the Auuthors

Annette Cowie, Adjunct Professor, University of New England; Han Weng, Research academic, The University of Queensland; Lukas Van Zwieten, Adjunct Professor, Southern Cross University; Stephen Joseph, Visiting Professor, School of Material Science and Engineering, UNSW, and Wolfram Buss, Postdoctoral fellow, Australian National University

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

Related Books

Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming

by Paul Hawken and Tom Steyer
9780143130444In the face of widespread fear and apathy, an international coalition of researchers, professionals, and scientists have come together to offer a set of realistic and bold solutions to climate change. One hundred techniques and practices are described here—some are well known; some you may have never heard of. They range from clean energy to educating girls in lower-income countries to land use practices that pull carbon out of the air. The solutions exist, are economically viable, and communities throughout the world are currently enacting them with skill and determination. Available On Amazon

Designing Climate Solutions: A Policy Guide for Low-Carbon Energy

by Hal Harvey, Robbie Orvis, Jeffrey Rissman
1610919564With the effects of climate change already upon us, the need to cut global greenhouse gas emissions is nothing less than urgent. It’s a daunting challenge, but the technologies and strategies to meet it exist today. A small set of energy policies, designed and implemented well, can put us on the path to a low carbon future. Energy systems are large and complex, so energy policy must be focused and cost-effective. One-size-fits-all approaches simply won’t get the job done. Policymakers need a clear, comprehensive resource that outlines the energy policies that will have the biggest impact on our climate future, and describes how to design these policies well. Available On Amazon

This Changes Everything: Capitalism vs. The Climate

by Naomi Klein
1451697392In This Changes Everything Naomi Klein argues that climate change isn’t just another issue to be neatly filed between taxes and health care. It’s an alarm that calls us to fix an economic system that is already failing us in many ways. Klein meticulously builds the case for how massively reducing our greenhouse emissions is our best chance to simultaneously reduce gaping inequalities, re-imagine our broken democracies, and rebuild our gutted local economies. She exposes the ideological desperation of the climate-change deniers, the messianic delusions of the would-be geoengineers, and the tragic defeatism of too many mainstream green initiatives. And she demonstrates precisely why the market has not—and cannot—fix the climate crisis but will instead make things worse, with ever more extreme and ecologically damaging extraction methods, accompanied by rampant disaster capitalism. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.

 

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook-icontwitter-iconrss-icon

 Get The Latest By Email

{emailcloak=off}

LATEST VIDEOS

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…
What Is A Hurricane Storm Surge and Why Is It So Dangerous?
What Is A Hurricane Storm Surge and Why Is It So Dangerous?
by Anthony C. Didlake Jr
As Hurricane Sally headed for the northern Gulf Coast on Tuesday, September 15, 2020, forecasters warned of a…
Ocean Warming Threatens Coral Reefs and Soon Could Make It Harder To Restore Them
Ocean Warming Threatens Coral Reefs and Soon Could Make It Harder To Restore Them
by Shawna Foo
Anyone who’s tending a garden right now knows what extreme heat can do to plants. Heat is also a concern for an…
Sunspots Do Affect Our Weather But Not As Much As Other Things
Sunspots Do Affect Our Weather But Not As Much As Other Things
by Robert McLachlan
Are we headed for a period with lower Solar activity, i.e. sunspots? How long will it last? What happens to our world…
Dirty Tricks Climate Scientists Faced In Three Decades Since First IPCC Report
Dirty Tricks Climate Scientists Faced In Three Decades Since First IPCC Report
by Marc Hudson
Thirty years ago, in a small Swedish city called Sundsvall, the Intergovernmental Panel on Climate Change (IPCC)…
Methane Emissions Hit Record Breaking Levels
Methane Emissions Hit Record Breaking Levels
by Josie Garthwaite
Global emissions of methane have reached the highest levels on record, research shows.
kelp forrest 7 12
How The Forests Of The World’s Oceans Contribute To Alleviating The Climate Crisis
by Emma Bryce
Researchers are looking to kelp for help storing carbon dioxide far beneath the surface of the sea.

LATEST ARTICLES

God Intended It As A Disposable Planet: Meet The Us Pastor Preaching Climate Change Denial
God Intended It As A Disposable Planet: Meet The Us Pastor Preaching Climate Change Denial
by Paul Braterman
Every so often you come across a piece of writing so extraordinary that you cannot help but share it. One such piece is…
Drought And Heat Together Menace American West
Drought And Heat Together Menace American West
by Tim Radford
Climate change really is a burning issue. Simultaneous drought and heat are increasingly likely for more of the…
China Just Stunned The World With Its Step-up On Climate Action
China Just Stunned The World With Its Step-up On Climate Action
by Hao Tan
China’s President Xi Jinping surprised the global community recently by committing his country to net-zero emissions by…
How Do Climate Change, Migration And A Deadly Disease In Sheep Alter Our Understanding Of Pandemics?
How Do Climate Change, Migration And A Deadly Disease In Sheep Alter Our Understanding Of Pandemics?
by Super User
A new framework for pathogen evolution exposes a world much more vulnerable to disease outbreaks than we previously…
Climate Heat Melts Arctic Snows And Dries Forests
What Lies Ahead For The Youth Climate Movement
by David Tindall
Students around the world returned to the streets in late September for a global day of climate action for the first…
Historic Amazon Rainforest Fires Threaten Climate And Raise Risk Of New Diseases
Historic Amazon Rainforest Fires Threaten Climate And Raise Risk Of New Diseases
by Kerry William Bowman
The fires in the Amazon region in 2019 were unprecedented in their destruction. Thousands of fires had burned more than…
Climate heat melts Arctic snows and dries forests
Climate Heat Melts Arctic Snows And Dries Forests
by Tim Radford
Fires now blaze under Arctic snows, where once even the wettest rainforests burned. Climate change delivers unlikely…
Marine Heat Waves Are Becoming More Common And Intense
Marine Heat Waves Are Becoming More Common And Intense
by Jen Monnier, Enisa
Improved “weather forecasts” for oceans hold hope for reducing devastation to fisheries and ecosystems around the world