Agriculture and food security under shifting climatic conditions
The global population is increasing day by day and is expected to increase further by 2050 (Ringler et al., 2016). This larger population will exert pressure on the prevailing resources. Further, due to urbanization and unbalanced use of fertilizers and pesticides, land for agriculture is decreasing rapidly. Despite technological advancements including mechanization of agricultural labor and development of high yielding varieties of crops, the global food security is still staggering. According to a study, approximately two billion people all around the world are undernourished in which children constitute a major part. Most of these children are short and thin for their age due to insufficient intake of food (Myers et al., 2017). Malnutrition is associated with approximately three million child deaths per year globally (Black et al., 2013). In the existing situation where population is increasing at a steep pace there is an urgent need to monitor global food demands. Added to the challenge of providing sufficient food to all, other major constraints are imposing a lot of pressure on land, water, etc. The anthropogenic activity also hastily alters the environmental conditions where global food production functions. Therefore, the biggest challenge is to keep up with the ever increasing human needs with respect to Earth’s natural systems transformation including the climate system.
Climate change affects agriculture by affecting the relationship between crops, pathogen weeds and pests, by exasperating the balance between biophysical resources like sunlight, quality of soil, availability of water, temperature CO2 concentration, etc. Manual labour, air pollution and pollinator abundance play major in agriculture production and are also affected by climate change, but are very poorly characterized. Crop plants are often highly sensitive to fluctuations in temperature and water. The land temperature worldwide has increased by 1⁰C due to increased atmospheric greenhouse gases (GHGs) when compared to 20th century average (https://www.ncdc.noaa.gov/cag/time-series/). Under representative concentration pathway (RCP) 4.5, which is the moderate emission of GHGs in the atmosphere, there would be a continuous increase in CO2 concentrations from a present level of 400-ppm to the level of 540 ppm by 2100 (Prather et al., 2013). However, according to IPCC (2014) if emission of GHGs becomes higher, termed as RCP 8.5, the level of CO2 would reach 940 ppm by 2100 resulting in land warming of 4.0 to 6.8⁰C (https://www.ncdc.noaa.gov/cag/time-series/). Increasing temperature also affects water resources in a multitude of ways like shifting precipitation, early seasonal snow melt, loss of glaciers, etc. which further affect agriculture. Though management and mitigation of agriculture risks linked to extreme events associated with climate change can help in achieving food security. Use of crop breeding technique might help in improving the performance under shifting climate conditions. Studies suggest abiotic stresses in plants can be overcome by using crop breeding as a means of increasing productivity alongside climate change mitigation (Evenson and Gollin, 2003; Burney et al., 2010). However, it is a very time consuming and intense labour demanding technique; thus, its implementation requires time. Therefore, management of food security and its development sustainably becomes a tedious task. Expansion, advancement and implementation of food security plan should be done appropriately, and must include practices for handling threats, tampering of products, and their storage and distribution in a well monitored way.
Energy security and shifting climate conundrum
According to International Energy Agency, energy security is defined as the continuous accessibility of energy sources to all the people globally at an affordable price. Energy security can be categorized in ways: 1) long-term energy security which focuses mainly on investments to supply energy on time, simultaneously with sustainable environmental needs and economic developments; 2) Short-term energy security which deals with the energy system to respond on time to sudden changes within the supply-demand balance. Absence of energy security is often associated with negative impacts on social and economic issues, and is related either to physical unavailability of energy, or non competitive or excessively volatile prices. Over the last few decades, global concern over security implications of global climate shift has increased tremendously. Climate change and energy security are considered as friends with asymmetric benefits (Chaturvedi, 2016) and are the key drivers for future energy policy. Increasing population and needs are not the only problem for food security but also for energy security. There has been an increasing pressure to deal with the challenge of maintaining energy security in world facing the problem of climate change. Increase in anthropogenic activities and technological advancements needs considerations as are the main source of GHGs. To ensure energy security, cost-effective policies are needed to be developed to provide sufficient and cheap energy with reduction in emissions for rapid economic growth. At present time, economic structure suffers from reduced energy efficiency with large consumption of energy and high emissions (Dodo, 2014). It is necessary to clearly understand the relationship between climate change and energy security to cope with future stresses. The studies conducted at international, national and local levels analyse climate change, and highlights the challenges associated with it (Dodo, 2014; Gregorio et al., 2019). Although, the influence of climate change on energy security has attracted interest of researchers and policy makers in recent years, but very less work has been done to understand linkage between climate change and energy security. It is an important area of interest because of 2 reasons: Firstly, energy is responsible for around 60% of emissions at the global scale (Baumert et al., 2005). Controlling emissions from energy will play vital role in climate mitigation and will support economic development and prosperity. Moreover, import of fossil fuels from unstable regions, or over-dependence on one supplier, are of great concern for many countries. To avoid such circumstances use of renewable sources can aid in climate change mitigation along with balancing energy security (Friedman, 2005). Secondly, significance of climate change on environmental sustainability plays a vital role in human security as well (Dalby, 2002). Therefore, efforts are needed to be made both conceptually and in practice to make energy security and climate-protection objectives fit together. Use of science and technology to increase the efficiency of energy requiring equipments and power plants and their economical utilization can reduce a lot of energy use. Selection of fuel for generating energy defines the level of emissions, for eg., when crude oil is used the C emission factor is 20 tC/TJ approx. whereas it is more when coal is used. Therefore, less carbon intensive fuel should be used to reduce emissions thoroughly (IPCC, 1997).
Microbes in balancing food and energy security, and climate change
Microbes are smallest forms of life on earth having largest uncultivated pool of biodiversity (Bhattacharyya and Jha, 2012). Microbes are the driving force for many functions of the ecosystem and thus could play crucial role in maintaining agriculture and energy security (Bhattacharyya et al., 2016). Furthermore, microorganisms play a vital role in every spectrum of life and microbial ecology thus becomes the frontier in present world facing several problems. The role of microorganisms in context of plant growth and promotion under various stresses is well established and their role as biological control agent cannot be denied. The traits possessed by PGPR such as P solubilisation, nitrogen fixation, production of siderophores, ACC deaminase, exopolysaccharides, phytohormones, etc. facilitate plants to grow efficiently under all circumstances. Rhizobacteria from genus Pseudomonas, Bacillus, Rhizobium, Azotobacter, Paenibacillus, etc. are involved in growth promotion. Some of these are efficient biocontrol agent for fungal pathogens in crops. The role of fungi belonging to genus Trichoderma as a biocontrol agent and nutrient acquisition cannot be denied.
During plant microbe interactions, plant root exudates acts as signals to attract microorganisms which sense chemical messages and activate complex cascade to initiate several responses in plant (Glick, 2012). Though microbes contribute in natural emission of gases like CO2, CH4 and N2O but their roles in the utilization of greenhouse gases is also elaborated and that’s why their role in climate change mitigation cannot be neglected (Richard et al., 2008, Mohanty and Swain, 2018). A change in climate induces changes not only in plants but also in microorganisms and affects plant–microbe relations. Use of microbial inoculants becomes important because of their ability to adapt to various agro climatic conditions and over wide range of temperature, pH and salt concentration (Kaur et al., 2018). Soil microbes are involved in biogeochemical cycling of elements like C, N, etc. Additionally, increase in productivity as a result of microbial inoculation influence GHG budget by limiting emission per unit productivity of GHGs. Therefore, accrued benefits from above mentioned traits of microorganisms can be regarded as their prominent role in mitigation of climate change.