Greenhouse Gases from Agriculture

Abstract

The rapidly changing global climate due to increased emission of anthropogenic greenhouse gases (GHGs) is leading to an increased occurrence of extreme weather events such as droughts, floods, and heatwaves. The three major GHGs are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The major natural sources of CO2 include ocean–atmosphere exchange, respiration of animals, soils (microbial respiration) and plants, and volcanic eruption; while the anthropogenic sources include burning of fossil fuel (coal, natural gas, and oil), deforestation, and the cultivation of land that increases the decomposition of soil organic matter and crop and animal residues. Natural sources of CH4 emission include wetlands, termite activities, and oceans. Paddy fields used for rice production, livestock production systems (enteric emission from ruminants), landfills, and the production and use of fossil fuels are the main anthropogenic sources of CH4. Nitrous oxide, in addition to being a major GHG, is also an ozone-depleting gas. N2O is emitted by natural processes from oceans and terrestrial ecosystems. Anthropogenic N2O emissions occur mostly through agricultural and other land-use activities and are associated with the intensification of agricultural and other human activities such as increased use of synthetic fertiliser (119.4 million tonnes of N worldwide in 2019), inefficient use of irrigation water, deposition of animal excreta (urine and dung) from grazing animals, excessive and inefficient application of farm effluents and animal manure to croplands and pastures, and management practices that enhance soil organic N mineralisation and C decomposition. Agriculture could act as a source and a sink of GHGs. Besides direct sources, GHGs also come from various indirect sources, including upstream and downstream emissions in agricultural systems and ammonia (NH3) deposition from fertiliser and animal manure.

Cuticle development and underlying transcriptome-metabolome associations during early seedling establishment

“…The past few decades have manifested increasing challenges to maintain global food production. Although there are many causes to these challenges, a major contributor is global climate change that is the consequence of anthropogenic production of greenhouse gases (e.g., CO 2 , CH 4 , N 2 O and fluorinated gases), which are the aftermath of increased industrialization of human activities (Zaman et al, 2021). Projecting forward therefore, food crops will likely have to contend with increased abiotic and biotic stresses, including drought, salinity, solar radiation, elevated temperatures, pathogens and pests (Gong et al, 2014).…”

Effects of microplastic ingestion on hydrogen production and microbiomes in the gut of the terrestrial isopod Porcellio scaber

“…The vials were sealed with airtight lids (caps with butyl septa) and overpressure was applied to all vials via injection of 2 ml air. Headspace hydrogen and methane mixing ratios were analysed for a period of 10 h with a gas chromatograph coupled to a pulsed discharge helium ionization detector as described (7890B, Agilent Technologies, JAS GC systems, Moers, Germany) [45].…”

A Portable Laser Spectroscopic System for Measuring Nitrous Oxide Emissions on Fertilized Cropland

“…Thus, measuring agricultural GHG emissions is necessary to understand the underlying processes in the soil and develop means to limit the cumulative GHG emissions. In a recent book (Zaman, [ 1 ]), the challenges for agricultural GHG measurements are described, and current methods for measurement of agricultural GHG emissions are reviewed. Therefore, Zaman’s book is used as the main reference in this publication.…”

“…Therefore, Zaman’s book is used as the main reference in this publication. Among the three major greenhouse gases CO 2 , CH 4 and N 2 O, the latter is mainly related to agricultural activities and the intense use of synthetic fertilizers [ 1 ]. With a global warming potential about 265 times higher than CO 2 [ 2 ], nitrous oxide emissions make agriculture a sector with a high impact on climate change.…”

“…At a laser emission wavelength of 4.5 µm, tests in the laboratory at negative pressure showed no cross-sensitivity to other gases in the air. Among the different approaches to measuring agricultural GHG fluxes, chamber-based methods are most frequently employed [ 1 ]. However, the use of gas collection chambers in the field may influence the emission flux compared to uncovered soil due to e.g., different temperature, humidity, etc.…”