CLIAVEClimate Focused Agricultural Vocational Education

Module 1 · Chapter 2

Climate change and its general impact on agriculture

Jaroslav Bernas, Petr Konvalina, Jaroslav Neumann · 16 min

ENTRCSROSRSL

The current global climate change phenomenon is primarily attributed to the combustion of fossil fuels (coal, oil, natural gas) and the alteration of land use, leading to the mineralization of organic matter. These activities, driven by human exploitation of fossil resources, deforestation, and the conversion of land for agriculture, have resulted in a significant increase in carbon dioxide (CO2) levels. This rise in CO2 concentration contributes to global warming by impeding the reflection of sunlight, thereby causing more heat to be trapped in the Earth's atmosphere. Furthermore, molecules such as methane (CH4) and nitrous oxide (N2O) have an even greater impact, with methane having a global warming potential twenty times higher than that of CO2 and nitrous oxide's potential being up to 300 times greater [10].

Agricultural production heavily relies on climate conditions, making it highly susceptible to the effects of climate change. Consequently, significant changes have been observed in various agricultural sectors over the past decade, prompted by the potential effects of climatic changes. Research in this field primarily focuses on understanding the physical implications of climate change on crops, livestock, and the associated economic consequences [3]. Agriculture, due to its scale and sensitivity to weather parameters, is considered the most vulnerable sector in the face of climate change, resulting in substantial economic impacts. Climatic events such as temperature and rainfall variations have a significant influence on crop yields. Tropical regions are generally more affected by climate change, as crops in these areas are already closer to their optimal temperature ranges, making them more susceptible to high-temperature stress [8].

Agriculture and climate change are interconnected in various ways, as climate change serves as a major cause of both biotic and abiotic stresses that negatively impact agricultural regions. Climate change affects agricultural activities through alterations in annual rainfall patterns, average temperatures, occurrences of heatwaves, changes in weed and pest populations, modifications in microbial communities, fluctuations in atmospheric CO2 levels, ozone depletion, and shifts in sea levels [11].

Predictions concerning the future global trends for greenhouse gas emissions from agriculture largely depend on physical and economic parameters that strongly influence total emissions. These parameters include the cost of fuel, economic development, the evolution of livestock numbers, increase in productivity, new technology, availability of water, deforestation, and consumer attitudes and diet [10]. Current scientific models predict substantial environmental changes caused by increased emissions of greenhouse gases. These changes will affect agriculture both in positive and negative ways. The forecast increase in global temperature between 1.4° C and 5.8° C will result in alterations in precipitation patterns. Extreme weather events (droughts, floods) are expected to occur more frequently. Seasonal variations in weather events may pose risks to traditional crop production methods either due to water constraints or a surplus of water and erosion. Soil stability will become crucial to store water in the soil profile, resisting severe weather events, and minimizing soil losses [10]. In general, soil erosion is caused by the action of water and wind on arable lands but also by frost and animals. Depending on topographic features, the soil may be lost entirely from a field or redeposited within it. The coarse fraction of the soil (sand and stones) is transported short distances, whereas the finer silt, clay, and organic matter can be moved well away from the site. This causes the remaining soil to become progressively coarser-grained and less fertile [13]. Vulnerable regions such as tropical and subtropical areas and high mountain regions are expected to suffer the most from climate change [10]. The situation is generally more serious in less developed countries where agroecosystems are already fragile, investment in agriculture is limited, and climate change is predicted to have its most devastating effects [12].

Projected climate changes are also most likely to affect the development and survival of pathogens. It is predicted that the climate or weather pattern change will increase the susceptibility of crops to various pests, diseases, and weeds pressure, which can decrease yield levels in general. Moreover, pests and diseases are more prevalent in humid and warmer regions. The other parameters, such as humidity, wind speed, temperature, and rainfall, can also impact crop yields. Plant–water relations are highly susceptible to changes in temperature and precipitation. Physiological changes are more likely to be affected by extreme changes in these parameters than by changes in mean climate. Plants’ response to climate change varies according to the plant species and developmental stage. There are species-specific thresholds for different crops. Their responses, such as elongation of roots, disturbance in growth angle of roots, and reduction in yield, vary among different species of plants [8]. During the climate change, precipitation patterns will change, with some areas becoming wetter but some leading agricultural regions becoming drier. Despite these patterns being challenging to predict, the climate model predictions are more uncertain for precipitation than temperature. However, the recent droughts in many parts of the world underscore the crucial role of changes in rainfall. Even if total annual precipitation is unchanged, agriculture may be harmed by changes in the seasonality or intensity of rainfall [4].

With the rise of environmental legislation and increased public interest in protecting the environment, the significance of effective environmental management in agriculture is now widely acknowledged. While the agricultural sector is slowly responding to these challenges, there is a growing voluntary movement towards better environmental practices in farming. The main environmental impacts associated with agriculture are primarily linked to pesticides and their residues, nitrogen compounds and emissions, livestock management, soil erosion, and nutrient losses that contribute to eutrophication. It's important to note that environmental impacts are not limited to chemical or biochemical measurements alone. Visual and aesthetic impacts, such as the appearance of the landscape, as well as socio-economic considerations like the implications for rural communities, pose more complex challenges to quantify [13].

Reaching a consensus on the interpretation, definition, and measurement of sustainability presents significant challenges. However, the increasing awareness of the environmental consequences associated with conventional farming systems has prompted a shift towards alternative approaches that explicitly address the externalities of farming. These alternatives strive to minimize negative effects, such as the impact of pesticides on wildlife or the impact of fertilizers on water supplies, by implementing changes within the farming system itself. While organic farming is often presented as the primary alternative to conventional production systems, it is not the only option. Within the realm of sustainable and alternative practices, other approaches like low-input, biodynamic, and regenerative systems are gaining recognition. For example, low-input sustainable agriculture has received significant research funding and support in the United States, focusing on reducing the use of certain agrochemical inputs without completely eliminating them. It is important to highlight that many countries have established distinct standards, certification procedures, and legislative frameworks that differentiate organic farming from other sustainable agriculture approaches. These distinctions are primarily for marketing purposes [14].

Environmental Impact of Agriculture

Despite the constant advancements in technology, our society remains heavily influenced by the landscape, climate, hydrology, soil, and organisms [9]. The interaction and reliance on the landscape are fundamental factors that must be taken into account when considering the potential for sustainable development, as our current landscape management practices are far from sustainable. One of the most pressing issues we face today, and will continue to face in the coming decades, is the problem of food production. Throughout thousands of years, this problem has been addressed by converting forests, pastures, and wetlands into arable land and intensifying agricultural practices.

The cultivation of crops stands as the sole viable source of food for human beings. As the global population continues to grow, the demands on our food supply will inevitably increase, leading to a rise in agricultural inputs. However, this increase in inputs is likely to create even greater environmental challenges from an agricultural standpoint than what we currently experience. While agriculture is essential for sustaining human life, how we treat nature will face significant challenges in the years to come. It will become increasingly crucial to limit the pressures arising from carbon dioxide emissions, biodiversity degradation, and water loss caused by intensive agricultural practices [5].

Expanding the Agricultural Area

Today, expanding agricultural areas by cultivation is increasingly difficult. Over the past 50 years, production has increased mainly through intensification per unit of land combined with a relatively slowly growing land base [2]. Most areas in temperate zones are already used for agricultural purposes. Deforestation, especially the cutting down of rainforests to produce soy or palm oil, has major and undeniable environmental consequences in terms of biodiversity loss and global warming.

Soil degradation

Soil is the basic unit of the ecological system and is largely a non-renewable resource. However, unfortunately, its degradation is a permanent and constant companion of agriculture and one of its most serious environmental problems. The biggest causes of soil degradation are monocultures, mineral extraction, uncontrolled grazing, deforestation, inappropriate tillage, water erosion, and incorrect application of agrochemicals. One of the solutions to prevent soil degradation is the afforestation of arable land or the transition from arable land to meadows, however, in a state where the demand for meat is increasing [6].

Demand for meat products

During the last 50 years, the global consumption of meat per person has doubled from about 20 kg per person per year in 1960, 2011 meat consumption was already more than doubled, and for the year 2050, the assumption is more than 50 kg per person per year [1]. This problem will worsen over time as the population and incomes increase. Meat, eggs, and dairy products will likely increase consumption, which will pressure the land to grow more corn, soybeans, and other crops needed to feed livestock. For example, in China, the production and consumption of pork increased dramatically. When compared to 1979, the consumption of pork increased five times on average per inhabitant of China. This demand alone in China has resulted in the taking of forests and their conversion to arable land and the massive conversion of pastures to arable land in Argentina, which has created a very high pressure on the land itself and its degradation, where such significant and extensive changes cannot be sustained in the long term.

Climate Change Adaptation in Crop Production

Establishing a precise definition of adaptation is crucial from the outset. One suitable definition could be: that adaptation refers to actions that mitigate the negative impacts or enhance the positive effects of climate change [7]. Temperature fluctuations and variations in rainfall patterns are the primary factors indicating environmental stresses, encompassing both positive and negative outcomes, with the negative effects being particularly concerning [11]. Due to the wide range of interests in adaptation, numerous definitions of climate adaptation have emerged. The Intergovernmental Panel on Climate Change (IPCC) defines adaptation as adjustments made in natural or human systems in response to actual or anticipated climate-related stimuli or their effects, aimed at minimizing harm or capitalizing on beneficial opportunities. Climate adaptation can also be defined as any action that sufficiently improves societal welfare to offset losses related to climate change. However, the problem with broad definitions is that they lose their significance when it comes to assessing the impacts of greenhouse gas emissions [7].

Even slight climate change poses significant challenges for agriculture. Unlike other industries, which can often implement relatively quick solutions in response to climate change, agriculture operates differently. It relies on natural processes that depend on specific proportions of nutrients, temperatures, precipitation, and other conditions. Agriculture worldwide has been optimized based on local climate conditions through decades of experimentation. Favourable conditions for crop growth include preferred average temperature and precipitation ranges, as well as precise timing and extreme value information [4]. While various changes in agricultural management and technologies, such as shifts in crop phenology and improved drought and heat tolerance, can enhance crop productivity, they do not necessarily represent true adaptations [7]. Adaptation to climate change is necessary but not sufficient. If global warming continues at the current rate, adaptation will become increasingly impossible within a matter of decades. A long-term solution must involve the rapid reduction of emissions to limit the extent of future climate change [4].

Ensuring productivity in crop production is of utmost importance. Crop yield and production are just two among many possible impact metrics, with social and economic outcomes also being widely considered. Any agricultural changes that enhance overall wealth and reduce vulnerability to extreme situations can be regarded as climate-adaptive [7]. Addressing the climate crisis in agriculture requires adaptation through the development of heat-resistant and drought-resistant crops and cultivars, as well as an urgent reduction of greenhouse gas emissions to minimize future climate-related damages [4]. Truly impactful actions in agriculture are relatively rare, contrary to how they are often portrayed or assumed [7]. According to Reynolds and Ortiz [12], sustainable and resource-conserving crop management technologies offer significant benefits under climate change.

These approaches include, for example:

1. Reduced tillage combined with crop residue retention can protect crops against severe climatic events, for example, by increasing water content in the soil

2. In addition, by improving the overall soil environment for root growth, such practices can support to fulfill of the yield potential of improved cultivars

3. Diversification of cropping systems helps to control soilborne diseases.

There are also longer-term benefits, which, for example, include the following:

4. Reduced environmental impact through the precision in applying N and water in case of irrigation and reduced use of diesel fuel related to agrotechnological operations.

5. Support the soils less prone to becoming degraded even as climate change increases the need for more intensive cultivation in still productive regions.

To better evaluate the impacts of climate change and identify more effective agricultural innovations for future climates, there is a need for consistent treatment of climate adaptation. It is important to acknowledge that some of the best agricultural innovations in the coming decades may not have direct adaptation benefits and should still be given attention [7]. In line with this, Reynolds and Ortiz [12] suggest implementing the following crop-oriented technical solutions to enhance food security:

  • Implementing crop and land management practices that maximize sustainable productivity using available natural resources while realizing the full genetic potential of cultivars.

  • Employing livestock management and breeding strategies to reduce greenhouse gas emissions.

  • Focusing crop breeding efforts on developing crops adapted to the harsher environments anticipated from climate change models.

  • Conducting systematic evaluation of genetic resources to better target their utilization in cultivar improvement.

  • Investing in target agroecosystems, considering factors such as cultivation, climate, biotic conditions, and soil characteristics, to evaluate different models of genetic adaptation systematically.

  • Integrating research techniques such as remote sensing for precise phenotyping, networks of field operations, and state-of-the-art molecular techniques to establish more accurate links between genome analysis and adaptive responses of crops.

  • Determining the theoretical limits of resource-use efficiency in cropping systems (including nutrients, water, and light) to establish realistic research goals for estimating potential productivity in future climate scenarios, considering crop response and potential adaptation to extreme climatic events.

  • Monitoring and modeling the spread of diseases and pests in response to climatic factors to minimize crop losses and reduce the risk of epidemics.

  • Establishing research consortia that bring together expertise and research platforms to solve common problems.

In conclusion, narrowing the gap between current and achievable yields can help mitigate the risk of food shortages [12]. The widespread interest lies in the potential of adaptation to reduce negative impacts or enhance the positive effects of climate change. It is essential to quantify the risks associated with greenhouse gas emissions reduction to evaluate costs and benefits properly. Additionally, there is a need to identify actions and investments that can improve prospects for food production and enhance food security [7].

References

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  2. Alston, J. M., & Pardey, P. G. (2014). Agriculture in the Global Economy. Journal of Economic Perspectives, 28(1), 121–146. https://doi.org/10.1257/jep.28.1.121

  3. Aydinalp, C., & Cresser, M. S. (2008). The effects of global climate change on agriculture. American-Eurasian Journal of Agricultural & Environmental Sciences, 3(5), 672-676.

  4. Bernard, L., Semmler, W., Ackerman, F., & Stanton, E. A. (2015). Climate Impacts on Agriculture. In L. Bernard & W. Semmler (Ed.), The Oxford Handbook of the Macroeconomics of Global Warming. Oxford University Press. https://doi.org/10.1093/oxfordhb/9780199856978.013.0024

  5. Bouma, J., & McBratney, A. (2013). Framing soils as an actor when dealing with wicked environmental problems. Geoderma, 200–201, 130–139. https://doi.org/10.1016/j.geoderma.2013.02.011

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  7. Lobell, D. B. (2014). Climate change adaptation in crop production: Beware of illusions. Global Food Security, 3(2), 72–76. https://doi.org/10.1016/j.gfs.2014.05.002

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  9. Martini, I. P., & Chesworth, W. (Ed.). (2010). Landscapes and societies: Selected cases. Springer.

  10. Niggli, U., Schmid, H., & Fliessbach, A. (2008). Organic farming and climate change. International Trade Centre (ITC), Geneva. 38 p.

  11. Raza, A., Razzaq, A., Mehmood, S., Zou, X., Zhang, X., Lv, Y., & Xu, J. (2019). Impact of Climate Change on Crops Adaptation and Strategies to Tackle Its Outcome: A Review. Plants, 8(2), 34. https://doi.org/10.3390/plants8020034

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  13. Skinner, J. A., Lewis, K. A., Bardon, K. S., Tucker, P., Catt, J. A., & Chambers, B. J. (1997). An Overview of the Environmental Impact of Agriculture in the U.K. Journal of Environmental Management, 50(2), 111–128. https://doi.org/10.1006/jema.1996.0103

  14. Stockdale, E. A., Lampkin, N. H., Hovi, M., Keatinge, R., Lennartsson, E. K. M., Macdonald, D. W., Padel, S., Tattersall, F. H., Wolfe, M. S., & Watson, C. A. (2001). Agronomic and environmental implications of organic farming systems. In Advances in Agronomy (Issue. 70, s. 261–327). Elsevier. https://doi.org/10.1016/S0065-2113(01)70007-7