Greenhouse Gas Emissions from Agriculture: A Growing Concern in the Current Era
The rapidly growing global population places an unprecedented strain on the agricultural system to fulfill calorie needs. It is anticipated that worldwide food production will need to twofold within the next 3 decades, with food demand anticipated to rise by 70% by 2050. While it is feasible to expand agricultural land by converting uncultivated areas to increase grain output, this method often leads to a decrease in carbon stocks found in natural vegetation and soils. The transformation of forests or grasslands into farmland to boost grain production may contribute to the swift depletion of global carbon reserves, threatening biodiversity and resulting in significant ecological repercussions. Intensified agricultural practices have been recognized as effective strategies for enhancing grain production. Nevertheless, such intensification necessitates increased inputs, including fertilizers, pesticides, and fuels, all of which contribute to greenhouse gas emissions and have detrimental environmental impacts. As a result, agriculture represents an inevitable land use change necessary for human survival, occupying about 40% of the Earth’s land.
India is primarily an agricultural nation, with over 58% of its rural households relying on farming for their income. Globally, agriculture is responsible for roughly 10–12% of greenhouse gas (GHG) emissions. In India, agricultural sector is accountable for 19% of the country’s entire GHG emissions. The emissions from agriculture largely stem from enteric fermentation, soil management, crop production, manure handling, and the blazing of crop residues. Additionally, agricultural practices such as land preparation, crop cultivation, irrigation, animal husbandry, fisheries, and aquaculture significantly influence GHG emissions. Consequently, it is essential to adopt climate-resilient agricultural production systems to improve farm productivity and mitigate GHG emissions from the agricultural sector.
Sustainable agricultural practices must achieve a balance between environmental health and economic viability to foster social and economic equity. The quest for sustainable development requires a comprehensive policy approach in contemporary nations. Recent research has concentrated on various facets of sustainable energy and environmental conservation. A primary environmental goal of sustainability is to mitigate adverse effects on both the environment and public health. Sustainable agriculture prioritizes environmental integrity, enhances agronomic productivity, and seeks to reduce detrimental environmental impacts. It minimizes reliance on external energy sources while boosting the profitability of agricultural systems. Furthermore, sustainable agriculture has the potential to enhance farm productivity and fulfill sustainability standards to address the growing demands of humanity, all while aiding in the restoration and sustainability of landscapes, the biosphere, and global systems. Key components of sustainable development include the reduction of greenhouse gas emissions, the effective utilization of renewable energy, and the enhancement of energy efficiency. Greenhouse gas emissions serve as a critical metric for evaluating the environmental sustainability of agricultural practices.
Key Factors for GHG Emission from Agriculture –
In the context of Indian agriculture, the prime greenhouse gases (GHGs) are resulting from enteric fermentation in livestock (54.6%), the use of fertilizers (19.1%), the farming of rice (17.5%), the management of manure (6.7%), and the blazing of agricultural residues in the fields (2.2%).
Enteric Fermentation: Enteric fermentation, a natural digestive process occurring in ruminants such as cattle and buffalo, represents a significant source of methane (CH4) emissions in India. With its extensive livestock population, India plays a crucial role as a global contributor to methane emissions resulting from enteric fermentation. India, having the biggest livestock population, emits 11.8 Tg yr−1 of CH4 through this process. Ruminant livestock has a fore stomach, referred to as the rumen, where a consortium of methanogenic bacteria generates CH4 via the anaerobic digestion of cellulose and other macromolecules found in their feed, utilizing H2 and releasing it through eructation from both the mouth and nose. The emissions of CH4 are influenced by various factors including the age of the animal, its body type, weight, and the type of feed provided.
Fertilizer Application: In the year 2023, the fertilizer sector in India released 25 million tons of CO2 equivalent (CO2eq), accounting for a considerable share of the nation’s overall greenhouse gas (GHG) emissions. This industry also plays a role in both production and field emissions, with synthetic nitrogen fertilizers identified as a primary contributor. The agricultural sector in India, which encompasses the use of fertilizers, is responsible for a significant fraction of the country’s total GHG and nitrous oxide (N2O) emissions.
Rice Cultivation: A major contributor to greenhouse gas emissions in India, especially methane (CH4) and nitrous oxide (N2O) is the agricultural sector, which significantly impacts the nation’s overall GHG footprint. In particular, rice farming ranks as the third-largest source of GHG emissions within Indian agriculture, following enteric fermentation and the application of fertilizers, representing 17.5% of the total emissions. The methane released from rice paddies in India is estimated to be 3.396 teragrams annually (equivalent to 71.32 million metric tons of CO2), primarily resulting from anaerobic decomposition occurring in flooded fields. Moreover, the application of nitrogen fertilizers in rice farming also contributes to N2O emissions.
Manure Management: Manure management in India, similar to the livestock sector, remains unorganized and is characterized by its dispersed nature. The key factors influencing greenhouse gas (GHG) emissions from animal manure include the volume of manure generated and the proportion that undergoes anaerobic decomposition. A significant portion of the animal manure produced in rural areas is utilized as fuel; however, there are also localized initiatives aimed at generating biogas through the systematic collection and management of animal manure. The total amount of manure is contingent upon the production rate per animal and the overall number of animals. The degree to which anaerobic decomposition of manure occurs is affected by the management practices employed. When manure is stored or treated in a liquid condition (for example, in lagoons, ponds, tanks, or pits), it is possible to decompose anaerobically, resulting in emission of considerable amounts of methane. In contrast, when manure is handled as a solid (for instance, in stacks and pits) or when it is applied to pastures and rangelands, it typically breaks down when oxygen is present, leading to minimal or no methane emissions.
Crop Residue Burning: Assessing the extent of crop residue burning throughout India is crucial due to its detrimental effects on public health, the environment, and agricultural productivity. Our research emphasizes district-level estimates of burning, offering a thorough seasonal evaluation of agricultural burning in India, which encompasses the burned area, dry matter incinerated, and gaseous emissions for seven primary crops from 2011 to 2020. It is estimated that emissions have risen by roughly 75% for carbon monoxide and greenhouse gases – including CO2, CH4, and N2O – between 2011 and 2020. The entire CO2 equal emissions escalated from about 19,340 Gg.yr-1 in 2011 to about 33,834 Gg.yr-1 in 2020. The majority of emissions were observed at the conclusion of the Kharif season, followed by the Rabi season, primarily due to the incineration of rice and wheat residues. Among various states in India, Punjab exhibits the highest level of burning activity, with 27% (2.0 million hectares) of its total cultivated land being burned in 2020. It is vital to highlight that Madhya Pradesh has emerged as the 2nd major contributor, representing 30% of the whole burned area across India in 2020.
Key Strategies to Reduce GHG Emissions from Agriculture –
Diversification:
Crop diversification, transitioning from unsustainable rice and wheat systems to nutritious and environmentally friendly crops, is essential for tackling climate change and malnutrition while safeguarding farmers’ incomes. Research indicates potential advantages, particularly in low-yield rice regions, such as enhanced nutritional value and decreased inputs and greenhouse gas emissions. Agroforestry and the diversification into pulses, oilseeds, vegetables, and fruits offer viable alternatives, requiring government assistance and incentives. The success of these initiatives depends on fortifying value chains and encouraging diversified diets among Indian consumers. Additionally, minimizing food waste through consumer awareness campaigns is vital for reducing greenhouse gas emissions.
Agro-Ecological Approaches:
Resource-intensive agriculture presents challenges, including methane emissions from rice paddies and nitrous oxide release. Agro-ecological methods, such as natural farming, provide viable solutions by enhancing ecosystem services and promoting biodiversity. The management of crop residue burning, exacerbated by monoculture practices and policy incentives, poses a significant challenge. Conservation agriculture, which includes techniques like no-till farming and crop rotation, effectively addresses this issue and contributes to the reduction of greenhouse gas emissions. The overuse of fertilizers and pesticides leads to pollution; therefore, implementing site-specific nutrient management based on soil health assessments is recommended. Organic farming, which utilizes botanical solutions and biological pest control methods, is environmentally friendly and helps lower greenhouse gas emissions. To foster broader adoption, government-supported nature-positive practices must undergo scientific validation.
Water-Use Efficiency:
The decrease in water resources serves as a significant indicator of climate change in India. Agriculture uses the 80% of freshwater, building efficiency indispensable. The government promotes micro-irrigation, which requires broader adoption. It is imperative to transition to a demand-based system and adopt techniques such as SRI, AWD, and DSR to optimize water usage in crops like paddy. Subsidies have led to the over-exploitation of groundwater, as seen in Punjab. The current policy focuses on achieving ‘more crop per drop,’ encouraging technologies that prioritize ‘irrigating the crop, not the land.’ Watershed management and community participation are vital for conserving soil and moisture. ICRISAT’s initiatives illustrate the potential for groundwater recharge and enhanced crop productivity. The integration of programs like MGNREGS and PMKSY for water harvesting and groundwater recharge is essential for sustainable agricultural water management, reducing ecological risks.
Renewable Energy Usage:
India plans to achieve a target of 500 GW in renewable energy, which should consist of the agricultural sector. The PM-KUSUM initiative is designed to enhance irrigation and increase farmers’ income through solar energy; however, the provision of subsidized electricity poses a barrier to its implementation. Establishing solar facilities on agricultural land and converting pumps to solar energy can provide farmers with additional income and enable them to become net energy producers. It is essential for government policy to redirect subsidies towards sustainable investments such as solar energy to effectively tackle the interconnections between water, energy, and food, minimize carbon emissions, and enhance the livelihoods of smallholder farmers.
Digital Agriculture:
The utilization of mobile phones in rural India can assist farmers by providing information and enhancing connectivity, thereby increasing productivity and income through various information services, market integration, and risk management strategies, particularly in relation to weather extremes. Weather advisories and market intelligence can significantly enhance both profitability and sustainability. Notable examples include the Meghdoot application and agricultural technology startups that leverage digital tools for effective marketing and risk management. It is essential for public policies to take these trends into account.
Research and Innovation Investments:
To address the effects of climate change on food and agriculture, it is essential to enhance investment in agricultural research and innovation to create climate-resilient varieties and technologies. The increase in CO2 levels and temperatures has a direct impact on crop productivity, quality, and the prevalence of pests and diseases. It is crucial to analyze greenhouse gas (GHG) emissions from agriculture’s related sectors to formulate effective policies. The significant emissions from animal agriculture highlight the need for life cycle assessment (LCA) studies within the livestock sector to ensure accurate GHG inventories and monitor emission reductions. There is a pressing need for greater government investment to bolster infrastructure and enhance the capacity of scientists and extension personnel. Adaptation strategies should aim to mitigate vulnerabilities faced by impoverished farmers. India must adopt policies that promote climate-resilient and sustainable agriculture, aligning with the commitments made post-COP26 through concrete actions.
Conclusion:
Agricultural growth plays a crucial role in satisfying the ever-growing food demands of the population. The area under cultivation is steadily expanding, and there is increasing pressure to enhance productivity per hectare due to the limited availability of land resources. Conventional agricultural practices result in the release of greenhouse gases, including methane, nitrous oxide, and, in certain instances, carbon dioxide. In light of the current climate change situation, it is imperative to decrease GHG emissions to keep global warming within 2 °C; otherwise, all forms of life on Earth face significant threats. This is particularly concerning as agriculture is responsible for approximately 80% of anthropogenic N2O emissions, 40% of CH4 emissions, and 1% of CO2 emissions. Agricultural practices present substantial opportunities to lower GHG emissions and alleviate the impacts of global warming. Consequently, mitigation strategies should encompass the adoption of improved management practices, the selection of suitable fertilizer management techniques, crop varieties, conservation agriculture, minimizing food waste, and preventing the burning of crop residues, among others.
Sources –
Indian Journal of Agronomy 68 (2): 115__125 (June 2023)
https://www.sciencedirect.com/science/article/pii/S2666154323000406
https://www.downtoearth.org.in/climate-change/indian-agriculture-the-route-post-cop-26-81154