Off-farm activities a ‘growing share’ of global food system GHG emissions

Off-farm activities before and after food production are making up a “growing share” of food system greenhouse gas (GHG) emissions around the world, according to a new study.

GHG emissions due to land use changes such as converting forests to agricultural land “have been decreasing over the past 20 years”, a decline that has been “counterbalanced” by increased emissions – notably high in industrialised countries – from off-farm activities.

These are some of the findings in a study led by the Food and Agriculture Organization (FAO) of the UN, published this week.

The report, ‘Greenhouse gas emissions from food systems: building the evidence base‘, estimates that food system emissions amounted to 16 billion tonnes of carbon dioxide or equivalents (CO2eq) in 2018, an 8% increase since 1990.

They now represent 33% of all human-caused GHG emissions.

Pledges to reduce GHG emissions

That, according to lead author Francesco Tubiello, a senior statistician and climate change specialist at FAO, highlights how the global food system represents a “larger GHG mitigation opportunity than previously estimated and one that cannot be ignored in efforts to achieve the Paris Agreement goals”.

Governments around the world are pledging to reduce their GHG emissions and pursue carbon neutrality, with many having included mitigation targets for their agriculture sectors in their national plans.

However, “action in food and agriculture goes well beyond impacts on farms and ecosystems”, according to the report.

Analysing emissions trends through the broader lens of food systems offers “additional insights and opens a range of possible solutions across the entire food production and consumption chain”.

The new study provides data sets that are being refined ahead of the UN’s Food Systems Summit 2021, with important components already available for consultation.

It considers GHG emissions linked to farm gate production, land use change at the boundary between farms and natural ecosystems and supply chains including consumption and waste disposal, to offer a “crisper and more granular assessment” of trends at the global, regional and country levels.

Report’s key findings

In 2018, GHG emissions from food systems were more than 16 billion tonnes CO2eq, largely emitted in developing countries in terms of absolute amounts, the report states.

“Global per capita emissions, which decreased from 1990 to 2010 from 2.9t to 2.2t CO2eq, were characterised by important differences between developed and developing economies.

“Per capita, emissions in developed countries, at 3.6t CO2eq in 2018, were nearly twice those in developing countries.

Farm gate and pre- and post-production emissions [those largely along supply chains, consumption and waste] represented two-thirds of the food systems total in 2018, with the role of emissions from land-use change having decreased over time.

“On agricultural land – crop and livestock processes within the farm gate but also including relevant land-use changes – amounted to 10.4Gt of CO2eq, 80% of which occurred in developing countries.

“That represents a 3% decline from 1990, as increased on-farm emissions of nitrous oxide and methane were more than offset by a decrease in emissions from land-use change such as deforestation or peatland degradation.”

Net forest conversion from natural ecosystems to agricultural croplands and pastures “remained the largest GHG emission source over this period, at nearly three billion tonnes CO2 per year – but declined significantly over time, by over 30% from 1990 to 2018”.

Declining trend of GHGs

The declining trend of GHGs linked to land-use change is welcome, according to the authors, “but points to the importance of maintaining and even accelerating the good progress achieved in recent years, while focusing on designing climate-friendly practices along the whole food supply chain, including the critical role that dietary choices and consumption patterns can play by impacting supply-side production activities”.

“Assessing the data and trends from a food systems perspective points to some immediately actionable pathways, such as: improving nitrogen use efficiencies in crop and livestock production; mitigating solid food waste disposal and optimizing on-farm energy use; as well as accelerated efforts to improve management of agricultural land while protecting natural ecosystems,” Tubiello added.

They also underscore that energy use beyond the farm gate will become an increasingly prominent component of total food system GHG emissions in the coming decades, so that food-related mitigation can benefit from a whole-system view and broader planning at national level.

“The goal is to complement current emissions on agricultural land with significant carbon removals, based on improved landscape management and more efficient production, thus advancing a carbon-neutral food system.”