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NESA Center Alumni Publication
Thokozani Andrew Chazema – A NESA Alumnus who works with the Malawi Defence Force. He is an adjunct lecturer at the Mzuzu University Department of Governance, Peace and Security Studies and Malawi University of Science and Technology, Bingu School of Culture and Heritage. Chazema is reading towards a PhD (Transformative Community Development) at Mzuzu University, Faculty of Environmental Sciences, Department of AgriSciences.
28 December 2023
ABSTRACT
Climate is an important factor in agricultural production. However, in recent years consistent warming and rise in global temperature have resulted in visible impacts on the agriculture sector across the world. On one hand, agricultural activities have degraded the biosphere contributing indirectly to climate change. Climate change has caused extreme weather conditions such as floods, droughts, and heat waves that stress animal and crop husbandry, resulting in low production. Changes in climate patterns have induced the movement of pests and diseases to other regions that did not experience particular pests and diseases such as avian influenza. On the other hand, agricultural practices have contributed to soil depletion and degradation through continuous cropping and animal husbandry leading to loss of soil fertility, deforestation, water pollution, and acidification. Although deforestation increases photosynthesis on crops through carbon dioxide fertilization, the crop yields lack nutrient content and deforestation is a huge culprit of carbon dioxide emissions responsible for global warming and subsequent changes in climatic patterns. Paddy rice and livestock produce methane which is a critical greenhouse gas responsible for global warming. The agriculture sector in general accounts for approximately a quarter of total greenhouse gas emissions worldwide impacting on food and environmental security.
Keywords: Climate change, global warming, deforestation, greenhouse gas, environmental security, food security
INTRODUCTION
Agriculture is a double-edged sword in that it is both a culprit and a victim of climate change. Climate influences agriculture but agriculture causes climate change. The nexus of agriculture and climate change come symbiotically in negative and positive perspectives. Hence this discourse asserts that agriculture is both a culprit and a victim of climate change. Agriculture is the most anthropogenic driver of climate change. Agriculture is the backbone of most developing countries’ economies, but it is highly susceptible to climate variability extremes. The effects of climate change are anticipated to heighten the vulnerability of crop and animal production. Climate change has become a global concern with severe and widespread destructive effects, warming of the planet threatening ecological systems, people’s livelihoods, and species survival. Agriculture is an important source of greenhouse gas (GHG) emissions and has been implicated as a serious contributor to climate change. The climate impacts anticipated for the globe are warming day and night temperatures all year round; changes in rainfall timing and quantities; changes in seasons, longer summers; increased climate variability for example floods, droughts, and heat waves; higher sea levels; and increasing frequency and intensity of extreme weather events (IPPC, 2007; Fereja, 2016). This discourse discusses extreme weather conditions, changes in rainfall patterns, and atmospheric carbon levels as variables of climate change that affect agriculture. Conversely, the agricultural factors of soil depletion and degradation, deforestation, biodiversity loss, coastal water pollution, and acidification, are discussed in this paper as anthropogenic drivers of climate change.
CONCEPTUAL FRAMEWORK
The guiding concepts for this discourse are climate change and agriculture. The anthropogenic drivers of climate change include greenhouse gas emissions, deforestation, land-use changes, cattle and rice production that increase methane emissions, and waste management and pollution. Greenhouse gases responsible for global warming are carbon dioxide (CO₂), methane (CH₄), and Nitrogen (N₂O) which leads to the greenhouse effect (Ruane and Rosenzweig, 2022; McCoy, 2020). The phrase ‘greenhouse effect’ was coined by a French mathematician, Jean Baptiste Fourier (1768–1830), who noticed that certain gases trapped heat in the atmosphere. The ‘greenhouse effect is vital to the survival of life on earth because it provides a warm layer near the earth’s surface (Leggett, 1999). But global warming infers that we are gaining more heat than we are losing in the earth’s energy budget. The belief is that man is adding to the greenhouse gases through his activities, and this is why the energy balance is becoming unstable leading to climate change that impacts agriculture.
CLIMATE CHANGE IMPACT ON AGRICULTURE
Climate change’s effects on agriculture must be understood in the context of the intertwined systems that affect food security and agricultural trade, including biological, socioeconomic, and political processes (Ruane and Rosenzweig, 2022). Rapid gains in socioeconomic development around the world may give the mistaken impression that climate change is not detrimental, but in developed countries, climate change impacts act as an additional burden holding back the pace of development. In addition to the biological impact of changing climate conditions on farms, future agricultural production is affected by economic and policy incentives across a wide variety of stakeholders and actors both locally and interacting through global markets (Ruane and Rosenzweig, 2022). These impacts appear more consistent in Malawi and beyond.
The Environmental Affairs Department notes that the adverse impacts that Malawi is facing appear consistent with those of other countries in the region; several flooding and related damages in the cities also happening in other countries in the region; severe shortages in runoff causing severe reductions in hydro-electric generation also happening all over Africa and the world has been a result of climate change. In addition to the latter, climate change causes extreme weather conditions, changes in rainfall patterns, and changes in atmospheric carbon dioxide levels which are drivers of the negative effects of agriculture.
EXTREME WEATHER CONDITIONS
Changes in climates over the last 30 years have resulted in extreme weather conditions that have subsequently reduced global agricultural production in the range of 1–5% per decade globally, compared with what would have been achieved in their absence, with particularly negative effects for tropical cereal crops such as maize and rice (Thornton, et al., 2018). The evidence is mounting that even at 2OC levels of warming; agricultural productivity is likely to decline across the globe but particularly across tropical areas and at 1.5OC levels of warming, impacts on human and natural systems will still be considerable. Impacts will be felt in all agricultural systems. Temperature shifts are likely to change the distribution and productivity of major cash crops such as coffee and cocoa in some tropical regions (Thornton et al., 2018). This will be so because crops and animal species adapt to a particular climate for a longer time of existence, hence extinction of some animals and crops in particular areas is predicted as the climate keeps changing.
Heat waves manifest due to climate change. Extremely hot temperatures cause plants to reduce photosynthetic activity, with prolonged exposure leading to leaf loss and potentially full crop failure. The impacts of heat waves depend on a plant’s developmental stage; heat waves during flowering (anthesis) can cause pollen to be sterile, leading to reproductive failure and low grain numbers (Ruane and Rosenzweig, 2022). On the other hand, heat waves cause heat stress to livestock, resulting in stunted growth and affecting dairy and meat production (Fereja, 2016). In this regard, both animals and crops suffer leading to food unavailability. Animals lose foliage and fodder in that crops fail due to heat waves. Animals can also die as a result crops will lose from organic manure produced by animals, whereas the climate will gain from the low production of methane as the methane-producing animals die.
According to a report by McKinsey & Company, heat waves can put over 4.5% of India’s GDP at risk by the end of the decade due to lost productivity and health effects caused by heat wave exposure. As much as 90% of India’s area lay in extreme heat danger zones, posing significant economic threats from reduced productivity and a decline in outdoor working capacity. Extreme heat could also lower the quality of life to 480 million and reduce GDP by 2.8% by 2050. Heat waves also impose high energy demands that could strain India’s power grids, as air conditioning and groundwater pumping become necessary, hence straining environmental security.
CHANGES IN RAINFALL PATTERNS
Changes in rainfall patterns cause unstable planting seasons, droughts, and floods, hence affecting food security in vulnerable groups. The resultant droughts due to changes in rainfall patterns are detrimental to agriculture and food security. Droughts reduce agricultural productivity and droughts are a result of climate change but affect agricultural produce be it crop or animal husbandry. Livestock production is under threat from the changing climate. This is because the natural pastures which a majority of the livestock owners rely on for feeding their animals are deteriorating in quality and the availability of the amount of fodder is decreasing. In addition to that, water sources available are not reliable as they sometimes dry up due to high temperatures and a shortage of rainfall. Livestock has been lost due to among other factors excessive heat, shortage of water and feed and unknown diseases (Fereja, 2016). All these effects are driven by droughts caused by climate change, particularly changes in rainfall patterns or absence of rains, resulting in a huge impact on animal production hence affecting animal husbandry.
A landmark study by Karki and Gurung (2012) on the impact of climate change on agriculture in Nepal revealed interesting findings on the impact of climate change on crop production. The study noted that the agriculture sector plays a fundamental role in the Nepalese economy and that it contributes about 80% of the exports and one-third of the county’s GDP, yet the industry is susceptible to climate change. The study further noted that cereal crops including rice, wheat, maize, millet, barley, and buckwheat are the mainstay of Nepal’s agriculture, yet Nepal is much vulnerable to climate change due to weather variability associated with rising temperature and changing patterns of precipitation. Rice is the prime food crop of the country which is facing a risk due to changes in the reliability of stream flows, more intense and potentially erratic monsoon rainfall, and the impacts of flooding. Approximately 64% of the cultivated areas are heavily dependent on monsoon rainfall and changes in the time and duration of this monsoon rainfall could affect the agricultural production significantly, especially rice yield resulting in food insecurity in Nepal, a developing country that could fail to cushion climate change effects on agriculture to be food secure. The changes in climatic conditions contribute to the emergence of new pests and diseases affecting the agricultural sector in many ways.
PESTS AND DISEASES
Climatic restrictions and stability on disease vectors, environmental habits, and disease-causing agents are important for keeping crop and animal diseases under control. Climatic changes influence livestock and crop health through several factors, including the range and abundance of vectors and wildlife and plant reservoirs, the survival of pathogens in the environment, and farming practice. Alterations in temperature and precipitation result in the spread of diseases and parasites into new regions or produce an increase in the incidence to which a particular disease is already prevalent, subsequently leading to a decrease in animal and crop productivity and an increase in crop and animal mortality (Rust and Rust, 2013).
The presence of vectors and climate changes may interact with each other and also with socio-economic factors and anthropogenic drivers of climate change, including habitat destruction and changes in land use resulting in increased mobility of people and movement of goods, including livestock and crops. Transmission of infection of zoonotic tick-borne diseases occurs when there is an overlap of activities between reservoir, vector, and humans. Changes in climatic conditions may impact all of these factors involved in disease transmission and their interactions (Gray et al., 2008; Randolph, 2008). Abiotic factors, such as temperature and day length, impose constraints on when and how ticks quest for hosts (Randolph, 2008). Beyond vector-borne diseases, intestinal nematodes develop in soil, and factors such as soil humidity and temperature have a strong influence on developmental rates (Brooker et al., 2002). Climate change is bound to have a further impact on heat-related mortality and morbidity and the incidence of climate-sensitive infectious diseases (Patz et al., 2005).
Climatic change is a driver of the emergency of new diseases. Fereja (2016) in his landmark study of the impact of climate change on livestock production and productivity affirmed that avian influenza has emerged and that the disease will continue to be spread by the international movement of animals and animal products. Avian influenza has caused considerable global concern about the potential for a change in host species from poultry to man and an emerging global pandemic of human influenza. Avian influenza and many if not all animal diseases have caused direct animal losses such as deaths, stunted growth, reduced fertility, and changes in herd structure and indirect losses, for example, additional costs for drugs and vaccines, added labour costs, and profit losses due to denied access to better markets and use of suboptimal production technology.
Fereja (2016) noted that large ruminants have intertwined systems effects and vulnerability to climate change. Large ruminants are generally regarded as the most important domestic livestock species in the world. The importance of large ruminants such as cattle is demonstrated differently in a specific region. In developed countries, their contributions are mainly restricted to commercial products such as meat and milk. In developing countries, they are a source of food, particularly protein for human diets, and they provide income, employment, transport, can serve as a store of wealth, and provide draft power and organic fertilizer for crop production (Fereja, 2016). Noting the importance of large ruminants in developing and developed regions, it is noteworthy to mention that the most affected are the developing regions as the ruminants are used in a range of activities, but their care would be difficult due to lack of capacity that increases their vulnerability to climate change.
AGRICULTURE’S IMPACT ON CLIMATE CHANGE
Agriculture as a culprit of climate change is phenomenal. Agriculture consequences of climate change are the production of greenhouse emissions and the exploration of new land for farming. The agricultural sector is not only vulnerable to weather and climate hazards but also a major contributor to greenhouse gas emissions and land use changes that drive climate change (Ruane and Rosenzweig, 2022). Historically deforestation is motivated in large part by the demand for more land for crop production and grazing pastures for animals, and agricultural systems are a net greenhouse gas emissions source owing to exchanges with carbon and nitrogen stocks in soils and fertilizers as well as methane from paddy rice and livestock enteric fermentation. Together the agricultural sector accounts for approximately a quarter of total greenhouse gas emissions (Ruane and Rosenzweig, 2022). It is these greenhouse gases that cause global warming resulting in climate changes subsequently affecting food security for vulnerable regions such as developing countries as they fail to cope with climatic changes due to lack of economic capacity. Agricultural practices also cause soil depletion and degradation that contribute to climate change.
SOIL DEPLETION AND DEGRADATION
Soil depletion and degradation is the decline in soil characteristics created by its inappropriate use, in areas of agricultural, industrial, or urban causes. It is a severe universal ecological crisis and may be aggravated by weather change. Soil degradation is one of the most important threats facing mankind which not only weakens the productive capability of an ecosystem but also affects the overall climate. Soil depletion and degradation destroy vegetation which provides food and habitat for animals. In turn, producing an imbalance of oxygen and carbon dioxide results in global warming which is a driver of climate change (Alam, 2014). Ecosystem services provided by soils are vital to the carbon and water cycles as such making a strong nexus between climate change and soil condition.
Alarm, (2014), further argues that some agricultural practices diminish soil fertility. Soil that is continually cropped or grazed loses its fertility because the normal cycle that returns mineral-rich dead plant matter to the soil is disrupted. Soil compaction that results from the use of heavy machinery destroys the structure of the soil, restricts water infiltration, and leads to increased erosion. The problem of soil erosion is big in the global village where extensive areas of land are cleared for food production. Population growth puts stress on the need for increased agricultural production as well as the clearing of land for cropping and firewood supplies. Resultantly unbalancing the ecosystem with an output of concentration of greenhouse gases that trap energy and warming the globe, hence change is climatic patterns.
DEFORESTATION
Archaic farming practices have rendered climate change susceptible to agriculture. Illegal logging to supply the international furniture and flooring markets is an especially big problem in Central and South America (the Amazon basin), as well as forests in Southeast Asia, Russia, China, and Africa. The places that are clear-cut from trees are used for unsustainable agriculture. Oftentimes, forests are clear-cut by illegal loggers, and then the remaining vegetation is burned, and the area converted into farmland. The two biggest drivers of slash and burn agriculture are cattle farming and monocultures. Cattle’s farming supplies the world’s demand for beef. Although many crops are planted in monocultures for example corn fields, and apple orchards, palm oil plantations are especially problematic because of their scale and the areas of the planet where these plantations have sprouted (McCoy, 2020).
Palm oil plantations are common in Latin America and Southeast Asia. 25% of Indonesia’s rainforests have been clear cut to put into palm oil plantations. During this process, the forests are slashed and burned, releasing massive amounts of carbon dioxide into the atmosphere and leaving many animals, especially endangered species, like orangutans, without a home. When this happens, carbon dioxide is released into the atmosphere, roughly 4.8 billion tonnes annually, which equals 8-10% of carbon dioxide emissions globally. This is incredibly alarming because forests also act as carbon sinks. So not only are we releasing carbon dioxide into the atmosphere by clear-cutting trees, but we are also taking away a valuable resource of sequestering carbon dioxide from the atmosphere (McCoy, 2020).
Animal husbandry creates demand for pastures that drive deforestation. On the other hand, animal production is a key contributor to global greenhouse gas emissions. Livestock like cattle and sheep use fermentation to break down food in their stomachs. This process creates methane and nitrous oxide, both gases have a higher potential for warming than carbon dioxide. These gases produce the equivalent of almost 10% of carbon emissions in the US (McCoy, 2020). On the other hand, it can be argued that greenhouse gases such as carbon dioxide have both positive and negative impacts on both climate change and agriculture, however, albeit with a small value of positivity.
The concentration of atmospheric carbon dioxide due to deforestation has a global warming effect, subsequently impacting agriculture as it induces extreme weather conditions; however, higher carbon dioxide concentrations benefit photosynthesis, resulting in carbon fertilization and higher productivity of crops and animal feed. Elevated carbon dioxide leads to efficient water use in plants. Plants in high carbon dioxide environments have more efficient stomatal gas exchanges, which reduce transpiration and improve water retention. Conversely, a high concentration of carbon dioxide reduces nutrition contents in plants. Yields of crops in carbon dioxide-rich environments have a lower percentage of key nutrients such as protein, iron, and zinc (Ruane and Rosenzweig, 2022). Yields with lower nutrients lead to high costs as they need supplements to reach the food content balance good for human and animal consumption. In turn, the vulnerable are affected as they fail to procure the supplements, resulting in food insecurity, retarded growth, and high production costs.
WATER POLLUTION AND ACIDIFICATION
Agriculture pollutes coastal water and causes acidification of oceans and lakes due to excessive application of chemical plant protection products such as fertilizers and herbicides. Agriculture, which accounts for 70% of water abstractions worldwide, plays a major role in water pollution. Farms discharge large quantities of agrochemicals, organic matter, drug residues, sediments, and saline drainage into water bodies. The resultant water pollution poses demonstrated risks to aquatic ecosystems and human security (Mateo-Sagasta, 2017). Water pollution and acidification lead to biodiversity loss and imbalance in the ecosystem resulting in climate changes.
In most high-income countries and many emerging economies, agricultural pollution has already overtaken contamination from settlements and industries as the major factor in the degradation of inland and coastal waters (Mateo-Sagasta, 2017). Nitrate from agriculture is the most common chemical contaminant in the world’s groundwater. Agricultural pollution, which is aggravated by increased sediment runoff and groundwater salinization, is an issue in climate change as it infringes on the ecosystem particularly on the energy budget of the earth (Ruane and Rosenzweig, 2022. Agricultural pressures on water quality come from cropping and livestock systems and aquaculture, which have all expanded and intensified to meet increasing food demand related to population growth and changes in dietary patterns (Mateo-Sagasta, 2017). Water pollution and acidification produce greenhouse gases and disturb the earth’s energy budget responsible for climate change.
The problematic part is that water pollution and acidification are likely to continue as developing countries seek to industrialize for economic growth. Consequently, the developed countries seem not to reverse the trend of agricultural industrialization which is a big culprit in climate change. In this regard, the gains made by developed countries on carbon markets will not stand as the developing countries seek to industrialize.
CONCLUSION
This discourse has discussed agriculture; animal and crop husbandry as both a culprit and a victim of climate change. The discourse concludes that climate change has a great bearing on agricultural production resulting in food insecurity. Climate change causes extreme weather conditions that put stress on animals and crops leading to their failure, low production, and death. Floods, droughts, and heat waves that come due to climate change have adverse effects on agricultural production as they reduce photosynthesis in plants and induce stress on animals leading to low production. Climate change strains environmental security. Unstable climate results in the spread of diseases and parasites into new regions, subsequently leading to a decrease in animal and crop productivity and an increase in crop and animal mortality.
The paper further affirms that anthropogenic drivers such as agricultural activities have an impact on climate change. Agricultural practices such as continuous cropping cause soil depletion and degradation which is a catalyst for the loss of soil fertility. When the soils are not fertile, the land loses the vegetation cover necessary for carbon sink. Agriculture induces deforestation in that land is cleared of trees that are burnt and crops and animals that emit greenhouse gases are raised contributing to climate change.
Furthermore, agricultural activities use fertilizer such as nitrogen which is responsible for trapping heat hence causing an imbalance in the earth’s energy budget resulting in global warming and change in climatic patterns. While deforestation is deemed a culprit of climate change, to some extent higher carbon dioxide concentrations due to deforestation benefit photosynthesis, resulting in higher productivity of crops and animal feed albeit with low nutrients content.
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