Authors: Ram Kishor Fagodiya, Kailash Prajapat, Ankita Jha and Babu lal Meena
Climate change is the variation in the mean state of the climate and climatic variables over the longer periods typical over decades. It includes the rise in temperature, melting of snow and sea level rise (often termed as global warming), changes in precipitation pattern (high intensity and low-frequency rainfall leading to drought and flood situation during cropping season), and increased frequency of extreme weather events (hailstorms etc.) (IPCC, 2014). The Indian Agriculture is highly prone to climatic risks. About two third of area under rainfed agriculture depends on the prevailing monsoon conditions. The different parts of the country are affected by different types of climatic risks. The frosting events in the north-west, floods in the north-eastern, cyclones in the eastern part and heat waves in the northwestern parts mainly affect the crop production in any country (Pathak and Chakrabarti, 2015).
Impacts of climate change on agriculture
Climate change affects agriculture both directly and indirectly by impacting crops, soils, livestock, and pest. The direct impacts are due to rising atmospheric concentration of carbon dioxide (CO2) and temperature. The increase in carbon dioxide (CO2) concentration has fertilization effects on the C3 plants thus, promoting their growth and productivity. Rise in temperature may cause increased crop respiration, shortening of crop duration, alteration in the photosynthetic pathways, augmented pest and disease incidence and their distribution, enhanced nutrient mineralization rate in soils and declined fertilizers use efficiency. Climate change has a considerable indirect effect on the land use system in India through the availability of irrigation water, frequency, and intensity of floods and droughts, soil organic matter decomposition, soil erosion and changes in pest distribution. The probable impacts of climate change on different sectors of Indian agriculture are mentioned below (Aggarwal et al., 2009).
- Increased atmospheric CO2 concentration is beneficial to several crops as it enhances the photosynthesis rate in C3 crops (e.g. rice and wheat); often termed as “carbon dioxide fertilization”.
- The current atmospheric concentration of CO2 is 410 ppm. At this concentration, photorespiration may occur in plants leading to oxygen (O2) fixation by RuBisCo enzyme. The effect of photorespiration is mainly seen in C3 plants; therefore, the effect of carbon dioxide fertilization would be higher in C3 as compared to C4 crops; as a C3 plant is more susceptible to carbon dioxide shortage.
- A rise in temperature causes increased respiration, decreased crop growth duration and reduction in the availability of irrigation water ultimately reducing the yields of major cereals crops.
- The productivity of major crops will be adversely affected due to increased frequency of extreme weather events (floods, droughts, cyclones and heat waves).
- In rainfed areas, crop productivity may reduce due to increased irrigation water demand and varying frequency and intensity of rainfall.
- Greater pest and disease incidence may occur due to the rise in temperature and humidity.
- Apple and wheat growing area may shift towards higher altitude due to rise in temperature in plains.
- Water is the most important and precious resource for crop production. The shortage of irrigation water may arise owing to climate change scenarios. The rising temperature and higher evapotranspiration have led to higher demands for irrigation water which further results in lowering of water table.
- The melting of snow in the Himalayas may lead to increased water flows in the rivers like the Ganges and the Brahmaputra, leading to declining in water availability in the long run.
- The high-intensity rainfall during monsoon season leads to considerable runoff; leading to floods and soil erosion in several parts of the country. However, this excess water can be harvested and can be used for irrigation purpose during the dry ( Kharif) season.
- The water balance in several parts of the country is predicted to be disturbed and the quality of water has turned out to be a major issue in the arid, semi-arid and coastal regions. In coastal regions, the seawater intrusion has affected the water quality to a large extent.
- The rise in temperature and atmospheric concentration of CO 2 will affect the organic matter (OM) thereby affecting the soil quality.
- Indian soils are low in OM and a further rise in temperature will fasten the OM decomposition process which will further lead to low soil OM.
- Higher CO2 level will increase the C: N ration of crops leading to slow decomposition of the crop residues.
- Nitrogen (N) mineralization rate will fasten due to rise in temperature. It may lead to loss of N through volatilization and denitrification process thus reducing the plant available nitrogen in soils.
- High-intensity rainfall and wind may lead to soil erosion.
- A rise in sea level may lead to the ingression of seawater in coastal lands making them less suitable for cultivation.
- Climate change also affects the feed production and nutritional security of livestock. Higher temperature generally leads to lignification of crop residue; thereby decreasing its digestibility.
- Global warming may cause scarcity of water resources for livestock and may further increase the water, shelter and energy requirements of livestock.
- Climate change is likely to intensify the heat stress in dairy animals which may affect their reproductivity and milk production.
To mitigate the adverse effects of climate change on Indian agriculture, several potential mitigation technologies are employed. Some of them are as mentioned below.
- Development of climate tolerant (heat, floods, droughts, and salinity) crop varieties.
- Development of low duration crop varieties
- Water conservation technologies (viz. rainwater harvesting, construction of check dams, farm ponds, etc.)
- Water saving technologies (micro-irrigation i.e. drips and sprinkler irrigation) may be employed.
- Need to demonstrate the conservation agriculture (CA) with Resource Conservation Technologies (RCTs) at farmers’ fields. Adjusting sowing date of wheat crop to avoid the terminal heat type of situations
- Need to adopt intercropping and crop diversification models to avoid the complete crop failure due to floods and droughts.
- Integrated Farming System (IFS), Integrated Nutrient Management (INM) system and Integrated Pest and Disease Management (IPM) practices must be followed.
- Crop insurance schemes and supply of credit to marginal and poor farmers may enhance the climatic risk-bearing capacity of farmers.
1. Aggarwal PK, Joshi HC, Singh SD, Bhatia A, Jain N, Shiv Prasad Choudhary A, Gupta N and Pathak H (2009). Agriculture and Environment. In Hand book of Agriculture, DIPA, ICAR, New Delhi, p 62-92.
2. IPCC (2014). Climate Change 2014: Impacts, Adaptation, and Vulnerability Working Group II Contribution to the Fifth Assessment Report. Cambridge University Press, Cambridge, UK and New York, NY USA.
3. Pathak H and Chakrabarty B (Editors) 2015. Climate Change and Agriculture: Technologies for Enhancing Resilience. Indian Agricultural Research Institute, New Delhi P237.
About Author / Additional Info:
I am working as Scientist, ARS at ICAR-CSSRI, Karnal, Haryana since last two years. I have done my MSc and PhD in the discipline of Environmental Science with specialization in climate change. I have worked on climate change adaptation and its mitigation aspect.