What Role Does Erosion Control Play In Reducing Greenhouse Gas Emissions?

Soil, a natural resource with thousands of years of formation, is crucial for crop growth and is endangered by wind and water erosion. Topsoil, the layer closest to the land’s surface, contains essential nutrients for crops. Soil erosion decreases this layer, which is threatened by deforestation and forest degradation. Over two decades ago, scientists proposed no-till management as a way to mitigate greenhouse gas (GHG) emissions through carbon storage in soils.

Agricultural activities account for 10-12% of total anthropogenic greenhouse gas emissions globally, with deforestation contributing 12-20% of these emissions. Forest degradation, which negatively affects a forest’s structure or function but does not significantly impact its structure, is also a significant contributor to climate change. To limit the magnitude of climate change, stringent GHG mitigation is necessary to prevent further biodiversity loss.

Soil erosion degrades land, limiting its ability to support fewer plants that can absorb climate-warming carbon dioxide. Soils could potentially sequester enough greenhouse gases in a year to equal about 5 of all annual human-made GHG emissions. Reforestation, agricultural land abandonment, and soil conservation practices can compensate for the impact of climate change on soil erosion.

No-till farming mitigates climate change by reducing the use of fossil fuel-powered machinery and helping soil hold on to carbon. When managed sustainably, soils can play an important role in climate change mitigation by storing carbon and decreasing greenhouse gas emissions. Healthy forests act as carbon sinks, absorbing billions of metric tonnes of CO2 annually.

There is a scientific debate on whether soil erosion creates a net source or a net sink of CO2, and reducing this loss and waste would reduce greenhouse gas emissions and improve food security.

How can we reduce greenhouse gas emissions significantly?

Climate change mitigation involves reducing or preventing greenhouse gas emissions from human activities, such as transitioning to renewable energy sources, enhancing energy efficiency, adopting regenerative agricultural practices, and protecting forests and ecosystems. The Paris Agreement, adopted in 2015, aims to limit global average temperatures to well below 2°C above pre-industrial levels, with a core ambition of limiting the increase to 1. 5°C.

This goal is crucial, especially for vulnerable communities already experiencing severe climate impacts, as it will result in less extreme weather events, sea level rise, stress on food production and water access, less biodiversity and ecosystem loss, and a lower chance of irreversible climate consequences. To achieve this, significant mitigation action is required, including a reduction in greenhouse gas emissions by 45% before 2030 and achieving net-zero emissions by mid-century.

How does erosion release co2?

The balance between erosion and uplift, the pace at which rock is replaced through mountain formation, determines the duration of material at the surface. High erosion rates strip minerals that remove carbon dioxide from mountains before they can weather through exposure to water and wind. This results in minerals that release carbon dioxide weathering rapidly, overwhelming the effect from minerals that remove carbon dioxide. Conversely, low erosion rates deplete minerals needed to remove carbon dioxide through weathering and do not impact climate.

At moderate erosion rates, minerals that remove carbon dioxide are exposed long enough for necessary chemical reactions to occur. The Goldilocks zones, where erosion is fast enough for new minerals to emerge but not so fast that they are swept away, are the only areas where this occurs at low erosion rates.

How can we prevent erosion?

Maintaining a healthy plant cover, mulching, planting cover crops like winter rye in vegetable gardens, and using crushed stone and wood chips in heavily used areas can help maintain vegetation. Other erosion controls, such as geo-textile materials or hydroseeding, can establish permanent cover and work well on steep slopes and heavy traffic areas. Contact your local landscape contractor or the RI Nursery and Landscape Association for more information. Addressing problem areas with high stormwater runoff can be done by redirecting stormwater and roof runoff to areas that can settle and dissipate water, such as a rain garden.

How does deforestation contribute to global warming?

Deforestation is the intentional removal of trees and forests, releasing carbon dioxide into the atmosphere, contributing to climate change. The largest deforestation occurred in the humid tropics, primarily in Africa and South America, between 1990 and 2020. The UN Food and Agriculture Organisation estimates that around 420 million hectares of forest were lost between 1990 and 2020. The annual rate of deforestation has slowed but remains 10 million hectares per year between 2015 and 2020.

The primary driver of deforestation is the global demand for agricultural commodities, with agribusinesses clearing vast tracts of forest to plant high-value cash crops like palm oil and soya. Deforestation and degradation contribute to 12-20% of global greenhouse gas emissions, with some tropical forests emitting more carbon than they capture.

REDD+, a family of policies, provides financial incentives to governments, agribusinesses, and communities to maintain and potentially increase forest cover. The plus in REDD+ refers to the role of conservation, sustainable management of forests, and enhancement of forest carbon stocks in developing countries. Incentives for forest protection are offered to countries, communities, and individual landowners in exchange for slowing deforestation and promoting reforestation and sustainable forest management. Proper involvement of local people in the REDD+ process may also help alleviate rural poverty.

Does soil erosion release CO2?

The debate over whether soil erosion creates a net source or net sink of CO2 is ongoing. Some scientists argue that soil erosion leads to more carbon sequestration from the atmosphere, as eroded carbon can be stored in long-term storage locations, creating a carbon sink. However, a new study challenges this idea by considering various drivers and processes necessary to predict future changes. The model shows that soil erosion is not likely to lead to a carbon sink but rather increases the release of CO2 into the atmosphere. Therefore, policies governing the agricultural sector should support measures to prevent soil erosion while maintaining or increasing soil organic carbon.

How can we reduce waste greenhouse gas emissions?

A reduction in energy demand will result in a decrease in the utilisation of fossil fuels and carbon dioxide emissions. The recycling of materials and the prevention of waste can result in the diversion of materials from incinerators, thereby reducing the emissions of greenhouse gases from waste combustion.

How does erosion affect the global carbon cycle?

Erosion can lead to terrestrial carbon dioxide sequestration if some of the carbon eroded from slopes is replaced by fresh photosynthetic matter or stored in stable organic matter pools in depositional landform positions. This process is influenced by various factors such as soil erosion, carbon dioxide concentration, and carbon flux from an Ohio Alfisol. Studies have shown that soil carbon and nitrogen cycles can be modeled during land use change, allowing for better understanding and management of these processes.

Does soil erosion remove carbon?

Soil organic carbon (SOC) levels are influenced by various ecosystem processes, including photosynthesis, respiration, and decomposition. Photosynthesis converts atmospheric CO2 into plant biomass, with input rates primarily determined by plant root biomass and litter deposited from shoots. Soil carbon is derived from the growth and death of plant roots and the transfer of carbon-enriched compounds from roots to soil microbes. Plants form symbiotic associations with fungi in the soil, providing energy and nutrients.

Decomposition of biomass by soil microbes results in carbon loss due to microbial respiration, while a small proportion of original carbon is retained in the soil through the formation of humus, a product that gives carbon-rich soils their characteristic dark color. Humus is highly recalcitrant, resulting in a long residence time in soil, while plant debris is less recalcitrant, resulting in a shorter residence time. Other ecosystem processes that can lead to carbon loss include soil erosion and leaching of dissolved carbon into groundwater.

When carbon inputs from photosynthesis exceed carbon losses, SOC levels increase over time. Decomposition of roots and root products by soil fauna and microbes produces humus, a long-lived store of SOC.

How does erosion affect the environment?

Soil erosion has a detrimental impact on the environment, leading to the loss of fertile land and contributing to increased pollution and sedimentation in streams and rivers. This, in turn, results in a decline in species diversity and the clogging of waterways. Furthermore, degraded lands exhibit an inability to retain water, thereby exacerbating the incidence of flooding.

How does erosion affect global warming?

Soil erosion has the effect of increasing atmospheric carbon emissions. This occurs as a result of the displacement of soil and its organic carbon, which releases more carbon dioxide into the atmosphere. Consequently, soil erosion serves to exacerbate the effects of climate change.