Agricultural Emissions

Agriculture finds itself in a paradoxical relationship with climate change, being both a significant contributor and a victim. Approximately 30% of greenhouse gas emissions are attributed to agricultural activities, largely due to the utilisation of chemical fertilisers, pesticides, and livestock waste. These practices have a significant environmental impact and contribute to the overall challenges we face in mitigating climate change.

The escalation of these practices, coupled with the rising food requirements of a booming global population and an increasing preference for dairy and meat products, indicates that this number could experience further growth.

The primary greenhouse gases emitted—nitrous oxide, carbon dioxide, and methane—exacerbate climate change and global warming, threatening the sustainability of agricultural production systems. Moreover, this analysis doesn’t fully account for the environmental cost associated with pesticide use, a factor that often goes overlooked.

Agricultural Emissions: Key Facts

From farm to fork, our food goes through a complex journey of production, storage, processing, packaging, transportation, preparation, and serving. At each stage, this process contributes to the release of greenhouse gases into the atmosphere.
Farming, in particular, contributes significantly to the release of methane and nitrous oxide, which are potent greenhouse gases. Livestock produce methane during digestion through enteric fermentation, which is then released through belching.
Nitrous oxide emissions can also be released from stored manure and organic waste in landfills. These emissions are an indirect result of the use of both organic and mineral nitrogen fertilizers.
In 2012, agricultural activities generated 10% of the total greenhouse gas emissions in the European Union. The period between 1990 and 2012 saw a 24% reduction in emissions from these activities due to strategic efforts, including a substantial reduction in livestock populations, an efficient application of fertilisers, and improved manure management practices.
On the flip side, agriculture in the rest of the world, including countries like India, experienced a contrasting trend. From 2001 to 2011, there was a 14% surge in global emissions due to crop and livestock farming. This trend indicates that global agricultural practices are becoming more carbon-intensive.
During this period, there was an 11% increase in emissions from enteric fermentation, which contributed to 39% of the total greenhouse gas outputs in the sector in 2011.
Considering the fundamental role of food in our lives, the task of decreasing greenhouse gas emissions from agriculture poses a significant challenge.
Meat and dairy products have the largest environmental impact in terms of carbon footprint, raw materials, and water usage per kilogram compared to any other food. When it comes to greenhouse gas emissions, the production of livestock and fodder alone contributes over 3 billion tonnes of CO2 equivalent.
Post-farm transport and processing are responsible for only a minuscule portion of the emissions associated with food. By reducing food waste and consuming fewer emission-intensive food products, we can make a significant contribution towards decreasing the greenhouse gas emissions produced by agriculture.

Source: FAO

Frequently Asked Questions About Agricultural Emissions

What portion of worldwide greenhouse gas emissions is attributed to agriculture?

In 2011, agricultural activities were responsible for the emission of 6 billion tonnes of greenhouse gases, accounting for approximately 13% of the global total. This ranks agriculture as the world’s second-highest emitting sector, surpassed only by the energy sector, which encompasses emissions from both power production and transportation.

What are the primary sources of greenhouse gas emissions from farms?

The majority of emissions from farms are attributed to methane (CH4) and nitrous oxide (N2O).
A significant 65 percent of these agricultural emissions worldwide are due to livestock releasing methane (CH4) and the effect of applying both organic and inorganic fertilisers, as well as wastes to the soil which produce nitrous oxide (N2O).
Other contributions to farm emissions come from the management of animal waste, cultivation of rice paddy fields, burning of crop residues in the field, and the use of fossil fuels in farm operations.
It’s noteworthy that the proportion of different emission sources can differ greatly at the individual farm scale, influenced by the nature of the crops cultivated, the farming methods implemented, and natural variables like climate, terrain, and water resources.

Who are the top contributors to global agricultural emissions?

In 2011, the highest contributors to agricultural emissions globally were, starting from the highest: China, Brazil, the United States, India, Indonesia, the Russian Federation, the Democratic Republic of Congo, Argentina, Myanmar, and Pakistan. These 10 nations were responsible for 51 percent of the world’s agricultural emissions.

Are global agricultural emissions changing?

Between 1990 and 2010, there was an 8 percent increase in global agricultural emissions. Projections indicate that by 2030, these emissions will rise by 15 percent compared to 2010 levels, reaching nearly 7 billion tonnes per year.

The rise in emissions is primarily fueled by population growth and shifts in dietary preferences in developing nations.
Asia and sub-Saharan Africa will witness the largest surge in agricultural emissions, contributing to two-thirds of the overall increase in food demand during the first half of the 21st century.

The production of vegetable oils and animal products, which have significant greenhouse gas (GHG) intensity, is projected to experience the highest growth among agricultural outputs.

What is the relationship between agriculture and land use change?

In 2010, land use change and forestry (LUCF) contributed to 4% of global emissions, and from 1990 to 2011, it accounted for 14% of the total global emissions.
The majority of these emissions are closely linked to agriculture, as they largely stem from deforestation resulting from the expansion of farms into tropical forests.
On the other hand, forest stocks are experiencing growth in numerous non-tropical regions, such as North America and China. This can be attributed primarily to the regrowth of forests on previously cultivated land.

What are the most significant prospects for mitigating agricultural emissions?

There are multiple potential paths to mitigate agricultural emissions, many of which involve changes to farming practices and food demand.

On the farming side, opportunities include:

Improved crop management practices, such as better fertilizer use and conservation tillage, can reduce environmental impact for a relatively low cost.
Enhanced grazing land management, including rotational grazing and altering forage composition.
Restoration of degraded lands and revitalization of cultivated organic soils to maintain sustainable productivity.

From a demand perspective:

A key strategy is a transition away from high-emission foods like beef.
According to research by the World Resources Institute, approximately 24% of calories produced for human consumption are lost or wasted in the food supply chain, highlighting the importance of addressing food waste and loss.

Understanding Methane Emissions

Where does methane originate from?

The majority of methane pollution comes from the agricultural sector.
Methane gas is produced by livestock like cows and sheep through digestion and waste, contributing to around 32% of methane emissions caused by humans.
The increase in population size and urbanisation has led to a higher demand for animal proteins, which could increase these emissions by 70% by 2050.
Besides livestock, methane is also produced in rice paddy fields. These fields are flooded, preventing oxygen from reaching the soil and creating perfect conditions for bacteria that produce methane. This process contributes to about 8% of human-triggered methane emissions.

Why is methane emission viewed as a critical environmental concern?

Methane is the primary instigator of ground-level ozone formation, a harmful air pollutant and greenhouse gas. Exposure to this gas is responsible for an estimated 1 million premature deaths every year.
It is a potent greenhouse gas, 80 times more capable of inducing global warming than carbon dioxide over 20 years.
Since the pre-industrial era, methane has been responsible for about 30% of global warming.
The rate of methane proliferation is accelerating, faster than any period since the inception of record keeping in the 1980s.
Amid the pandemic-induced lockdowns of 2020, a peculiar trend emerged: while carbon dioxide emissions experienced a slowdown, atmospheric methane levels witnessed a significant increase. This intriguing phenomenon, as revealed by data from the United States National Oceanic and Atmospheric Administration, highlights the complex interplay between agricultural activities and methane emissions.

What steps can we take to reduce methane emissions?

We can start by revamping our farming and animal-rearing practices.
This overhaul can involve using advanced technology, moving towards diets rich in plants, and exploring other protein options.
These changes are crucial to reduce the emission of harmful greenhouse gases and to keep the global temperature increase within 1.5°C, as outlined in the Paris climate accord.

How can farmers contribute to reducing methane emissions?

Farmers have a critical role to play in reducing methane emissions through various strategies:

By providing livestock with higher-quality feed, farmers can enhance animal health, productivity, and size, thereby increasing outputs while reducing methane production.
Research is currently being conducted on alternative feeds that could lessen the amount of methane produced by cattle.
Efficient manure management through methods like cover, compost, or biogas production can also help lower methane emissions.
For rice farms, methane emissions could be slashed by 50% by employing alternate wetting and drying techniques. Instead of continuously flooding fields, irrigation and draining could be performed two to three times during the growing season. This method not only reduces methane production but also requires 33% less water, making it a cost-effective approach.

Is there any benefit to lowering methane emissions in the fight against climate change?

Reducing methane emissions is crucial in the battle against climate change. While carbon dioxide lingers in the atmosphere for hundreds, even thousands of years, methane has a much shorter lifespan, breaking down after roughly a decade.
Therefore, if we take immediate and significant action to cut methane emissions, it will result in near-term climate benefits, unlike carbon dioxide.
This rapid effect of methane reduction is vital in our efforts to maintain global warming within the 1.5°C target.