The world’s food system, agricultural practices, and land use are a significant contributor to climate change — together emitting roughly a quarter of our current greenhouse gas emissions. Most of these emissions come from land use (especially deforestation), methane emissions (mostly from cattle), and nitrous oxide emissions (primarily from fertilizer overuse and manure). To help address climate change, we must reduce these emissions, first and foremost. In this primer, we have outlined a wide variety of ways to reduce agricultural emissions, which together present highly actionable steps towards addressing this part of the climate change problem.

Moreover, our land use and agricultural practices can be changed — using “regenerative” style techniques, and others — to create temporary carbon sinks on land. These carbon sinks work by sequestering carbon within biomass and soils, significantly raising the level of these carbon stocks above their present-day values. While the potential for these types of sinks is substantial, there are challenges facing them too. In particular, we must be aware of the limits on the potential size of biomass and soil carbon stocks, and their tendency to slowdown carbon accumulation after several years or decades — whereas emissions reductions can continue indefinitely. And we must recognize the need to manage carbon sinks well into the future to avoid releasing the carbon back into the atmosphere if the practices that sequestered it are discontinued or if natural disasters like droughts or fires create a disturbance.

In addition, if grazing animals are used in the regenerative farming practice, the system must carefully address how it, on net, can overcome the methane emissions from livestock, even as soil stocks eventually slow their rates of carbon accumulation. Finally, it is much more challenging to measure and predict soil carbon sequestration than emissions reductions.

Addressing climate change in the food, agriculture, and land use sector can use two parallel, and complimentary, sets of tools — reducing the primary emissions from agricultural practices and enhancing carbon sinks on agricultural lands. This means that — in theory — improving land use and our food system can dramatically reduce a quarter of the world’s greenhouse gas emissions and remove significant amounts of already-emitted carbon dioxide from the atmosphere. We strongly endorse approaches that focus both on immediate emissions reductions from the FALU sector and long-term investments in regenerative agriculture that can advance farming practices, significantly improve local environmental conditions and soil resilience, and create substantial carbon sinks that can also help address climate change.

It is important to be aware of the key differences between emissions reductions and sequestration strategies (Table 6.1). For example, emissions reduction takes place immediately, while carbon sequestration often takes several years or decades to kick in. In addition, carbon sequestration often continues for several decades until soils and biomass slow their rates of sequestration, whereas emissions reductions can continue indefinitely.
Most important: emissions reductions are irreversible, but carbon sequestered in soils and biomass can be quickly returned to the atmosphere if regenerative farming practices are ceased or due to natural disasters including those caused by climate change. Finally, emissions reductions and carbon stored in aboveground biomass are fairly easily measured, predicted, and quantified, while soil carbon sequestration presents many challenges for prediction as well as economically viable measurement and monitoring.