Environment

day one project

Pathways to Net-zero Soil Loss by 2050

11.01.21 | 4 min read | Text by Elizabeth Stulberg & Jo Handelsman & Kayla Cohen & Ray Boyle

Introduction

The current administration should announce its intention to achieve net-zero soil loss by 2050. This target aligns with President Biden’s plan to “mount a historic, whole-of-Government-approach to combating climate change,”¹ would help fulfill the administration’s commitment to achieving a net-zero-emissions economy by 2050,² and is key to protecting our nation’s agricultural productivity.

Healthy soil is essential to food production. Less well recognized is the vital role that soil plays in climate modulation. Soil is the largest terrestrial carbon repository on the planet, containing three times the amount of carbon in Earth’s atmosphere.³ Soil represents a potential sink for 133 billion tons of carbon (equal to 25 years of U.S. fossil- fuel emissions).^{4 5} Using soil to offset emissions generates significant co-benefits. Carbon sequestration in soil nourishes soil ecosystems by improving soil architecture and increasing water-holding capacity. Deeper and more fertile soil also supports biodiversity and enriches natural habitats adjacent to agricultural land.

Over two-thirds of the United States is grassland, forestland, and cropland.⁶ Land practices that increase the amount of carbon stored underground⁷ present a relatively low-cost means for President Biden’s administration to pursue its goal of net-zero carbon emissions by 2050.⁸ But lost soil can no longer serve as a carbon repository. And once lost, soil takes centuries to rebuild. Increasingly extreme climate events and soil-degrading industrial farming practices are combining to rapidly deplete our nation’s strategic soil resources. The United States is losing 10.8 tons of fertile soil per hectare per year: a rate that is at least ten times greater than the rate of soil production.⁹ At this rate, many parts of the United States will run out of soil in the next 50 years; some regions already have. For example, in the Piedmont region of the eastern United States, farming practices that were inappropriate for the topography caused topsoil erosion and led to the abandonment of agriculture.^{10 11} The northwestern Palouse region has lost 40–50% of its topsoil,¹² and one-third of the Midwest corn belt has lost all of its topsoil.¹³

Soil loss reduces crop yields, destroys species’ habitats that are critical to food production, and causes high financial losses. Once roughly half of the soil is lost from a field, crop yields and nutrient density suffer. Maintaining a desired level of agricultural output then requires synthetic fertilizers that further compromise soil health, unleashing a feedback loop with widespread impacts on air, land, and water quality — impacts that are often disproportionately concentrated in underserved populations.

Climate change and soil erosion create a dual-threat to food production. As climate change progresses, more extreme weather events like intense flooding in the northeastern United States and prolonged drought in the Southwest make farmland less hospitable to production. Concurrently, soil erosion and degradation release soil carbon as greenhouse gases and make crops more vulnerable to extreme weather by weakening the capabilities of plants to fix carbon and deposit it in the soil. Halting soil erosion could reduce emissions, and building stable stores of soil carbon will reduce atmospheric carbon.

Prioritizing soil health and carbon sequestration as a domestic response to the climate and food-security crises is backed by centuries of pre-industrial agricultural practices. Before European occupation of tribal lands and the introduction of “modern agricultural practices,” Indigenous peoples across North America used soil protective practices to produce food while enhancing the health of larger ecosystems.¹⁴ Some U.S. farmers adhere to principles that guide all good soil stewardship — prevent soil movement and improve soil structure. Practices like no-till farming, cover cropping, application of organic soil amendments, and intercropping with deep-rooted prairie plants are proven to anchor soil and can increase its carbon content.^{15 16} In livestock production, regenerative grazing involves moving animals frequently to naturally fertilize the soil while allowing plants to recover and regrow. If all farms implemented these practices, most soil erosion would halt. The challenge is to equip farmers with the knowledge, financial incentives, and flexibility to use soil-protective techniques.

This document recommends a set of actions that the federal government — working with state and local governments, corporations, research institutions, landowners, and farmers — can take towards achieving net-zero soil loss by 2050. These recommendations are supported by policy priorities outlined in President Biden’s Discretionary Budget Request for Fiscal Year 2022 and the bipartisan infrastructure deal currently under negotiation in Congress. Throughout, we emphasize the importance of (1) prioritizing storage of stable carbon (i.e., carbon that remains in soils for the long term) and (2) addressing environmental injustices associated with soil erosion by engaging a broad group of stakeholders.

Firm commitments to restore degraded land will establish the United States as an international leader in soil health, help avoid the worst impacts of climate change, strengthen food security, advance environmental justice, and inspire other countries to set similar net-zero targets. The health of our planet and its people depend on soil preservation. Our nation can, and should, lead the way.