The best of EcoWatch, right in your inbox. Sign up for our email newsletter!
How Carbon Farming Can Help Solve Climate Change
By David Burton
Under the 2015 Paris agreement, nations pledged to keep the average global temperature rise to below 2C above pre-industrial levels and to take efforts to narrow that increase to 1.5C. To meet those goals we must not only stop the increase in our greenhouse gas emissions, we must also draw large amounts of carbon dioxide (CO2) from the atmosphere.
The simplest, most cost effective and environmentally beneficial way to do this is right under our feet. We can farm carbon by storing it in our agricultural soils.
Soils are traditionally rich in carbon. They can contain as much as five percent carbon by weight, in the form of soil organic matter—plant and animal matter in various stages of decomposition.
But with the introduction of modern agricultural techniques, including the plow, soil organic matter content has dropped by half in many areas of the world, including parts of Canada. That carbon, once stored in the ground, is now found in the atmosphere and oceans as CO2 and is contributing to global warming.
The organic compounds found in soil are the glue that hold soil particles together and help give the soil structure. Like the walls of a building, this structure creates openings and passageways that allow the soil to conduct and store water, contain air, resist soil erosion and provide a habitat for soil organisms.
Plowing breaks apart soil aggregates and allows microorganisms to eat the soil organic compounds. In the short-term, the increased microbial activity releases nutrients, boosting crop productivity. In the long-term the loss of structure reduces the soil's ability to hold water and resist erosion. Ultimately, crop productivity drops.
How Can We Make Soil Organic Matter?
First and foremost, we need to disturb soil less. The advent of no-till and reduced tillage methods have allowed us to increase the carbon content of soils.
No-till and direct-seeding methods place the seed directly into the soil, minimizing the disturbance associated with seedbed preparation. The lack of disturbance allows the roots and crop residues from the previous crops to form soil organic matter. It reduces the degradation of the soil organic matter already present in the soil.
In Canada, we are already benefiting from reduced tillage. In the Prairies, no-tillage agriculture has increased from less than five percent of the land area in the early 1990s to almost 50 percent in 2006.
The situation is a bit more complex in Eastern Canada. The region's soil type and climate make it less easy to build soil organic matter. At Dalhousie's Atlantic Soil Health Lab, we are exploring the potential of various cropping practices to increase soil organic matter content in the soils of Atlantic Canada. While the potential to store carbon may not be as great as in Western Canada, the benefits of increased soil organic matter content are far greater because of the critically low levels of organic matter.
Secondly, we can use more diverse crop rotations. Forage crops—such as grasses, clovers and alfalfa—penetrate the soil with extensive root systems that lead to the formation of soil organic matter. Short rotations dominated by crops that have poor root systems (corn, soybeans) are not effective in building soil organic matter.
Farmers can also build soil organic matter by adding organic amendments such as animal manure, composts, forestry residues (wood chips) or biosolids to the soil.
Using the right amount of fertilizer is also important. Fertilizers can improve plant growth, lead to larger roots and add more plant matter to the soil in the unharvested portion of the crop. However, too much nitrogen fertilizer can result in the production of the powerful greenhouse gas nitrous oxide and offset the benefit of increased soil organic matter formation.
Farmers Need Economic Incentives
Project Drawdown, a non-profit organization that researches solutions to global warming, has estimated that global farmland restoration (building soil organic matter) could remove 14 gigatones (billion tonnes) of CO2.
This would reduce the CO2 in the atmosphere below the current 400 parts per million—a level unpassed for several million years—while developing more fertile, resilient soils to feed people for years to come and keep forests intact.
These approaches seem like obvious solutions. Why are they not more widely adopted? The short answer is economics.
The benefits of drawing down CO2 and building soil organic matter play out over decades. But the costs associated with these practices often do not have increased returns in the short-term.
Farmers often make decisions in response to short-term economic pressures and government policies. Improved soil management is a public good. We need economic tools and short-term incentives that encourage producers to adopt these practices for the good of all.
Reposted with permission from our media associate The Conversation.
EcoWatch Daily Newsletter
‘Companies Should Not Be Allowed to Use Hazardous Ingredients in Products People Use’: Michelle Pfeiffer Speaks Up for Safer Cosmetics
The beauty products we put on our skin can have important consequences for our health. Just this March, the U.S. Food and Drug Administration (FDA) warned that some Claire's cosmetics had tested positive for asbestos. But the FDA could only issue a warning, not a recall, because current law does not empower the agency to do so.
Michelle Pfeiffer wants to change that.
The actress and Environmental Working Group (EWG) board member was spotted on Capitol Hill Thursday lobbying lawmakers on behalf of a bill that would increase oversight of the cosmetics industry, The Washington Post reported.
By Julia Conley
Scientists at the United Nations' intergovernmental body focusing on biodiversity sounded alarms earlier this month with its report on the looming potential extinction of one million species — but few heard their calls, according to a German newspaper report.
The climate crisis is a major concern for American voters with nearly 40 percent reporting the issue will help determine how they cast their ballots in the upcoming 2020 presidential election, according to a report compiled by the Yale Program on Climate Change Communication.
Of more than 1,000 registered voters surveyed on global warming, climate and energy policies, as well as personal and collective action, 38 percent said that a candidate's position on climate change is "very important" when it comes to determining who will win their vote. Overall, democratic candidates are under more pressure to provide green solutions as part of their campaign promises with 64 percent of Democrat voters saying they prioritize the issue compared with just 34 percent of Independents and 12 percent of Republicans.
President Donald Trump has agreed to sign a $19.1 billion disaster relief bill that will help Americans still recovering from the flooding, hurricanes and wildfires that have devastated parts of the country in the past two years. Senate Republicans said they struck a deal with the president to approve the measure, despite the fact that it did not include the funding he wanted for the U.S.-Mexican border, CNN reported.
"The U.S. Senate has just approved a 19 Billion Dollar Disaster Relief Bill, with my total approval. Great!" the president tweeted Thursday.