Greenhouse Gas Emissions from Agriculture

Greenhouse Gas Emissions from Agriculture

Agriculture contributes towards climate change through Greenhouse Gas Emissions and by the conversion of non-agricultural land such as forests into agricultural land.
In 2019 the IPCC reported that 13%-21% of anthropogenic greenhouse gasses came specifically from the Agriculture, Forestry, and Other Land Uses Sector (AFOLU).
Emissions from agriculture of NITROUS OXIDE, METHANE and CARBON DIOXIDE make up to half of the greenhouse-gases produced by the overall food industry, or 80% of agricultural emissions. Animal husbandry is a major source of greenhouse gas emissions.
Agriculture contributes directly to greenhouse gas emissions through practices such as rice production and the raising of livestock.
The THREE MAIN CAUSES of the increase in greenhouse gases observed over the past 250 years have been Fossil Fuels, Land Use, and Agriculture.
Farm Animal Digestive Systems can be put into two categories: Monogastric and Ruminant.

Ruminant cattle for beef and dairy rank high in greenhouse-gas emissions;
Monogastric, or pigs and poultry-related foods, are low.

The consumption of the monogastric types may yield less emissions. Monogastric animals have a higher feed-conversion efficiency, and also do not produce as much methane.
Furthermore, CO2 is actually re-emitted into the atmosphere by plant and soil respiration in the later stages of crop growth, causing more greenhouse gas emissions
There are many strategies that can be used to help soften the effects, and the further production of greenhouse gas emissions - this is also referred to as Climate-Smart Agriculture. Some of these strategies include →

a higher efficiency in livestock farming, which includes management, as well as technology;
a more effective process of managing manure;
a lower dependence upon fossil-fuels and nonrenewable resources;
a variation in the animals' eating and drinking duration, time and location;
and a cutback in both the production and consumption of animal-sourced foods.

A range of policies may reduce greenhouse gas emissions from the agriculture sector for a more sustainable food system.

Emissions overview

Agricultural activities emit the greenhouse gases carbon dioxide, nitrous oxide, and methane.
The 10 countries with the largest agricultural emissions in 2011 were (in descending order): China, Brazil, United States, India, Indonesia, Russian Federation, Democratic Republic of Congo, Argentina, Myanmar, and Pakistan. Together, these countries contributed 51% of global agricultural emissions.

Carbon Dioxide Emissions

Carbon dioxide emissions come from things such as tilling of fields, planting of crops, and even the shipment of crops or food cultivated to markets for revenue.
Agricultural related emissions of carbon dioxide account for around 24% of the global greenhouse gas emissions.
To help mitigate carbon dioxide emissions farm practices such as reduce tillage, decrease in empty land, return biomass residue of crop to soil, and increase use of cover crops can be promoted.

Methane Emissions

Methane emissions come from livestock such as Cows Belching and are the number one contributor to agricultural greenhouse gases globally.
Animal agriculture is a large source (30%); primarily because of enteric fermentation by ruminant livestock such as cattle and sheep.
According to the Global Methane Assessment published in 2021, methane emissions from livestock (including cattle) are the largest sources of agricultural emissions worldwide

While the residence time of methane is much shorter than that of carbon dioxide its potency is 28 times stronger its contribution to warming.
Not only does livestock contribute to harmful emissions but they also require a lot of land and may overgraze which leads to unhealthy soil quality and reduced species diversity.
Plant agriculture, including both food and biomass production, constitutes a fourth group (15%), with rice production being the largest single contributor.
A few ways to reduce methane emissions includes consumption of plant-rich diets with less meat, feeding the cattle more nutritious food, manure management, and composting.

Nitrous Oxide Emissions

Nitrous oxide emission comes from the increased use of synthetic and organic fertilizers. Fertilizers increase crop yield production and allows the crops to grow at a faster rate.
Different management practice such as water conservation through drip irrigation, nutrient monitoring to avoid overfertilization, and the use of a cover crop in place of fertilizer application may help in reducing level of nitrous oxide emissions.

Prelim Bits