Out of the Air and into the Soil

Sep 27, 2017 | Sustainable Agriculture |

The Dirt:

The importance of healthy soil cannot be underestimated. Healthy soil has a direct impact on food security and our environment. But world soils are in the infirmary. They need more carbon to bring them back to health. Can we take carbon out of the air, and put it back into soils?  Remember when we said how important it is to plant a tree…?

Today, climate change discussions are primarily focused around ways to prevent or curb CO2 emissions. However, what also deserves our attention are the possible solutions for removing the excess CO2 that is currently in our atmosphere. Scientists are researching the best ways to manage this excess carbon dioxide— but we very rarely hear of this progress. In this piece, we ask you to look no further than beneath the soles of your feet for a solution.

CO2 not absorbed by carbon cycle = climate change discussions

For millions of years, the world’s oceans and terrestrial plants have worked in harmony to regulate atmospheric levels of carbon dioxide. As we discussed in Carbon: The Dance of Life, the earth inhales and exhales CO2. Carbon is exchanged (or “cycled”) among Earth’s oceans, atmosphere, ecosystems, and geosphere.

Today, the amount of excess anthropogenic CO2 in the atmosphere is 0.04%. This extra CO2—approximately 16 billion metric tons— is not circulating in the carbon cycle and is the focus of the greenhouse effect and climate change discussions. So, what on earth can we do to sequester or store that extra CO2…?

…Have we been standing on the answer this whole time?  Soil is the connection between food security, clean water, habitat biodiversity AND carbon sequestration – clean air.

The answer may seem obvious, but it has only become clearer through advancements in the science and biology of soil.

Soil, plants, and oceans are natural “carbon sinks,” which means they absorb and store carbon dioxide from the atmosphere. Together, plants and oceans absorb about one-half of atmospheric CO2

Plants absorb carbon dioxide from the air, combine it with water and light, and make carbohydrates — the process known as photosynthesis. The carbon is stored in the living tissues and roots of the plants.

Carbon is the main component of soil organic matter (SOM)!  Soil organic matter is essential to healthy soil. SOM improves soil structure and fertility, and soils high in SOM will retain water, reduce runoff, increase soil aeration, and improve nutrient uptake for plants. Healthy soil will provide a healthy crop!

Scientists are in agreement that most notably since the industrial revolution, gigatons of soil carbon have been lost due to agricultural land use and land cover changes. But this carbon debt can be reversed! Around the world, marginal and degraded lands can be replanted with trees and other vegetation which will put them back into the business of absorbing atmospheric CO2 and ultimately storing that carbon in the soil.

One solution to address excess atmospheric CO2:

Michael Pollen narrates this video on Soil Solutions to Climate Problems

Scientists at UCDavis estimate that U.S. rangelands alone could potentially sequester up to 330 million metric tons of carbon dioxide in their soils. Additionally, croplands (that utilize crop rotations and cover cropping) are estimated to lock up more than twice that amount—up to 770 million metric tons. That’s the CO2 emissions equivalent of powering 114 million homes with enough electricity for a year.
Professor Rattan Lal, director of Ohio State University’s Carbon Management and Sequestration Center, notes that restoring soils of degraded and decertified ecosystems has the potential to store an additional 1 billion to 3 billion tons of carbon annually. This is equivalent to roughly 3.5 billion to 11 billion tons of CO2 emissions. (Annual CO2 emissions from fossil fuel burning are almost 10 billion metric tons.)
“Regardless of the actual amount, two things are certain: we have a global soil carbon deficit that can be addressed immediately by transferring atmospheric CO2 into soil humus through plant biomass, and we know restoring soil health is the only way we can provide enough food and water to everyone on the planet.” — Center for Food Safety

How much is 1 ton of Carbon? It is difficult to visualize something we cannot see, but the folks at Real World Visuals have come up with some graphics to put this in perspective:
One metric ton of carbon dioxide would fill a sphere 10.07 meters across (33’).

Strategies to plant more trees and vegetation

There are certainly many organic and conventional farmers around the world who already plant cover crops and utilize conservation agricultural practices (such as crop rotations, low till or no-till farming). However, these practices must be made even more mainstream. Conservation ag practices can help sequester carbon in the soil and the widespread farmer adoption of these practices depends on awareness, available resources, and incentives.
Existing government programs like the USDA NRCS offer funding opportunities for farmers who take steps to improve soil as well as water and air quality. Some states, like Massachusetts, Maryland, New York, California, and Vermont, have passed specific legislation and made incentive programs available to help farmers take action.
Additionally, there are demonstration farms across the world to show farmers that these practices do indeed work. No-till on the Plains, based in Ghana, successfully practices all of these soil health-building initiatives and hopes to share best practices and spread awareness to local farms.
The University of California at Davis, through Russell Ranch, has an ongoing 100-year study that measures the long-term impacts of crop rotation on conventional, organic, and mixed farming practices. This initiative measures the inputs of water, nitrogen, carbon, and other elements in farming and judges their effect on the farm’s sustainability.

NGOs and Non-Profits are taking action…

Carbon offset credits—which have been criticized as not doing enough to actually reduce fossil fuel emissions— offer incentives for companies across all sectors to reduce their carbon footprint by restoring forests and wetlands that have been degraded or lost through development.

For example, The Nature Conservancy created a voluntary Carbon Offset Program. This initiative has worked with conservation organizations, private companies, communities, landowners and government agencies around the world to restore forests and other important ecological habitats. Additionally, Ducks Unlimited, a leader in wetland conservation, has restored or protected over 14 million acres of wetlands and prairie since 1937.

The American Carbon Registry (ACR) recently announced it has issued more than 100 million tons of carbon offset credits—the equivalent of taking over 21 million cars off the road for a year.
The benefits associated with these projects is not just carbon sequestration and improved soil production. Reclamation of unproductive lands, reforestation of stripped forests, and restoration of wetlands, prairies and rangeland provide a diverse and healthy habitat for wildlife and other organisms. These healthy ecosystems also improve air and water quality.
“Scientific and economic challenges still exist, but none are serious enough to suggest that carbon capture and storage will not work at the scale required to offset trillions of tons of carbon dioxide emissions over the next century.” (Schrag, D.P., et al)

The Bottom Line:

The debate on climate change certainly isn’t going anywhere. But rather than focusing all of our energy on the source of this excess CO2, we need to better understand how we can manage the carbon dioxide that is already in our atmosphere. Put simply, terrestrial plants help regulate the levels of CO2 in the atmosphere. Rebuilding forests, replanting prairies, preserving and restoring wetlands, and utilizing cover crops on farmland are all proven strategies to not only sequester carbon but also provide important ecological benefits to wildlife and our environment. So, let’s all plant a tree!

Sources:

What is Carbon Sequestration, www.kgs.ku.edu/Midcarb/sequestration.shtml. Accessed Sept. 2017.

“A Climate Change Solution Beneath Our Feet.” Science and Climate, 19 May 2017, climatechange.ucdavis.edu/news/climate-change-solution-beneath-feet/. Accessed Sept. 2017.

Burwood-Taylor, Louisa. “Soil Health Must No Longer Take a Back Seat to Plant Science.” AgFunderNews, 13 Apr. 2017, agfundernews.com/noble-foundations-buckner-soil-health-must-no-longer-take-a-back-seat-to-plant-science.html?utm_source=AgFunder%2BUpdates&utm_campaign=af9d319d37-April_20_2017&utm_medium=email&utm_term=0_7b0bb00edf-af9d319d37-98169637. Accessed Sept. 2017.

“Cover crops can sequester soil organic carbon.” University of Illinois at Urbana-Champaign, College of ACES, Dec. 2014, news.aces.illinois.edu/news/cover-crops-can-sequester-soil-organic-carbon. Accessed 27 Sept. 2017.

Mcphate, Mike. “California Today: To Fight Climate Change, Heal the Ground.” The New York Times, The New York Times, 31 May 2017, www.nytimes.com/2017/05/31/us/california-today-climate-change-soil-initiative.html?smid=pl-share. Accessed Sept. 2017.

“Natural Resources Conservation Service.” Cover Crops and Soil Health | NRCS, www.nrcs.usda.gov/wps/portal/nrcs/detail/national/climatechange/?cid=stelprdb1077238. Accessed Sept. 2017.

“Noble Research Institute.” Noble Foundation, www.noble.org/. Accessed Sept. 2017.

“SOIL & CARBON: Soil Solutions to Climate Problems.” Center For Food Safety, 2015.   https://www.centerforfoodsafety.org/files/soil-carbon-pamphlet_finalv2_88688.pdf

“Soil as Carbon Storehouse: New Weapon in Climate Fight?” Yale E360, e360.yale.edu/features/soil_as_carbon_storehouse_new_weapon_in_climate_fight. Accessed Sept. 2017.

“Soil as Carbon Storehouse: New Weapon in Climate Fight?” Yale E360, Mar. 2014, e360.yale.edu/features/soil_as_carbon_storehouse_new_weapon_in_climate_fight. Accessed Sept. 2017.

“Soil carbon FAQ (Frequently asked questions).” Soil carbon FAQ (Frequently asked questions) | Soil Carbon Coalition, soilcarboncoalition.org/faq. Accessed Sept. 2017.

“SOIL CARBON SEQUESTRATION FOR IMPROVED LAND MANAGEMENT.” FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, 2001.   http://www.fao.org/3/a-bl001e.pdf

“Soil Organic Carbon: The Hidden Potential .” FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, 2017.   http://www.fao.org/3/a-i6937e.pdf

“Soils are endangered, but the degradation can be rolled back.” FAO – News Article: Soils are endangered, but the degradation can be rolled back, www.fao.org/news/story/en/item/357059/icode/. Accessed Sept. 2017.

“Welcome to the PCOR Partnership Video Clip Library.” Video Clip Library | Plains CO2 Reduction Partnership, www.undeerc.org/pcor/video-clip-library/#tabs-2. Accessed Sept. 2017.

“What Is CO2 Sequestration?” What is CO2 Sequestration | Plains CO2 Reduction Partnership, www.undeerc.org/pcor/sequestration/whatissequestration.aspx. Accessed Sept. 2017.