One of the major challenges facing humankind is to provide an equitable standard of living for the present and future generations: adequate food, water, energy, safe shelter and a healthy environment. Climate change is a change in the statistical properties of the climate system that persists for several decades or longer—usually at least 30 years. Unlike weather change, which is periodical, Climate change occurs over time in decades. It may be due to natural processes, such as changes in the Sun’s radiation, volcanoes or internal variability in the climate system, or due to human influences such as changes in the composition of the atmosphere or land use. Global environmental issues such as land degradation, loss of biodiversity, stratospheric ozone depletion along with human-induced climate change, increasing atmospheric concentrations of CO2, methane and nitrous oxide, plus some chemically manufactured greenhouse gases such as halocarbons threatens further more drastic climate changes.
Climate change is likely to contribute substantially to food insecurity in the future, by increasing food prices and reducing food production. Food may become more expensive as climate change mitigation efforts increase energy prices. Water required for food production may become scarcer due to increased crop water use and drought. Competition for land may increase as certain areas become climatically unsuitable for production. Besides, extreme weather events, associated with climate change may cause sudden reductions in agricultural productivity, leading to rapid price increases.
The “Global Risk Report 2020” published by World Economic Forum lists climate change as the top global threat over the next decade while the Global Climate Risk Index places India at fifth position among the countries most vulnerable to the climate change crises. The past few years have seen an increase in awareness of the impacts of climate change on the Indian agricultural ecosystem both among policymakers as well as the general population.
Unfolding the Crisis
India’s agricultural productivity is in the danger of getting severely impacted. Issues such as greenhouse gas emissions, increased frequency of extreme weather outcomes, average annual temperatures taking a northward shift and rising sea levels are only some of the factors that could adversely impact India’s agricultural sector. Central to the food security of the nation, any ripple in this sector is bound to cause a domino effect in the whole economy. In absence of any adaptation and mitigation measures, the yield of Rabi and Kharif crops are expected to go down by 12 & 15% respectively thus impacting self-sufficiency in food production and pulling down the income of the farmers and the rural population of India. Indian agriculture remains largely dependent on monsoon with around 52% of the agricultural land non-irrigated. This has left it uninsured against the vagaries of weather. The pattern of the Indian Monsoons is expected to alter in the next decade both spatially and temporally with a change in arrival and departure dates, increased intensity of rainfall as well as larger breaks between bursts of monsoon. This is sure to change the sowing and harvesting cycles for which Indian farmers will have to be prepared in advance. An economic survey indicates that non-irrigated areas will face a greater effect of climate change-related impacts.
Impacts on Agriculture and Food Production
Food production in India is sensitive to climate changes such as variability in monsoon rainfall and temperature changes within a season. Studies by Indian Agricultural Research Institute (IARI) and others indicate a greater expected loss in the Rabi crop. The simulation studies by Indian Institute of Tropical Meteorology (IITM), Pune, estimated that annual mean surface temperature is expected to rise by the end of the century, ranges from 3 to 5° C with warming more pronounced in the northern parts of India. Other impacts on agricultural and related sectors include lower yields from dairy cattle and a decline in fish breeding, migration, and harvests. Global reports indicate a loss of 10-40% in crop production by 2100.
Impact of climate change on soil
- Both the organic matter and carbon to nitrogen ratio (C: N ratio) will diminish in a warmer soil temperature regime.
- Drier soil conditions will suppress both root growth and decomposition of organic matter and will increase vulnerability to erosion. Increased evaporation from the soil and accelerated transpiration from the plants themselves will cause soil moisture stress.
Impact on Pests, Diseases and Weeds
- Impacts on Plant Pathosystems: Climate change has the potential to modify host physiology and resistance and to alter stages and rates of development of the pathogen.
- Climate change is likely to cause a spread of tropical and subtropical weed species into temperate areas and to increase the numbers of many temperate weed species currently limited by the low temperature at high latitudes.
Effect of Rising Temperature
- Extreme periods of high temperature are particularly harmful for crop production if they occur when the plants are flowering – if this single, critical stage is disrupted, there may be no seeds at all.
- Every 1°C rise in temperature reduces wheat production by 4-5 Million Tonnes. Small changes in temperature and rainfall have significant effects on the quality of fruits, vegetables, tea, coffee, aromatic and medicinal plants, and basmati rice.
Effect of Rising CO2 Levels
- It will bring changes in soil moisture and infestation by pests and diseases because of rising temperature and relative humidity. Such effects reduce crop duration, increase crop respiration rates, evapotranspiration, decrease fertilizer use efficiency.
- Crop Loss: At elevated CO2, increased partitioning of assimilates to roots occurs consistently in crops such as carrot, sugar beet and radish. If more carbon is stored in roots, losses from soil-borne diseases of root crops may be reduced under climate change.
Effect of Precipitation
- Raindrops physically dislodge the insects from their hosts such as Leafhoppers, Planthoppers, Thrips, Cutworms etc. while others drown to death e.g., Mealybugs, pupae of the Fruit fly, Helicoverpa, Spodoptera, Etiella, Rice Stem Borers etc. Heavy rainfall causes pest epizootics by fungal pathogens
- In contrast, for foliar diseases favoured by high temperature and humidity, increases in temperature and precipitation under climate change may result in increased crop loss
- For short-season crops such as wheat, rice, barley, oats, and many vegetable crops, an extension of the growing season may allow more crops in a year.
- Longer-season cultivars can be sown to provide a steadier yield under more variable conditions.
- Late maturing varieties and alteration of time of sowing to take advantage of the longer growing seasons needs to be adopted.
- Changes in cropping pattern (shift from rice-wheat cropping system to another favorable crop mix) may be adopted. Crop diversification in Canada and China has been identified as an adaptive response.
- Heat and drought tolerant, pest resistant, salt-tolerant varieties would be beneficial. Genetic engineering and gene mapping offer the potential for introducing a wider range of traits.
- Minimum, reduced or conservation tillage technologies, in combination with the planting of cover crops and green manure crops, offer substantial possibilities to reverse existing soil organic matter, soil moisture, soil erosion, and nutrient loss to combat further losses due to climate change.
- Water resources in the semi-arid regions are expected to decrease due to climate change. Increased evaporation (resulting from higher temperature), combined with changes in precipitation characteristics, has the potential to affect agriculture – the predominant user of water. Better water management is required for enhancing crop productivity and ensuring food security. Generally, irrigated agriculture is less adversely affected than dryland agriculture but adding irrigation is a costly affair as it is dependent upon the availability of water supplies.
National Action Plan on Climate Change (NAPCC)
NAPCC identifies measures that promote our development objectives while also yielding co-benefits for addressing climate change effectively. It outlines several steps to simultaneously advance India’s development and climate change-related objectives of adaptation and mitigation. The following eight National Missions form the core of the National Action Plan, representing multi-pronged, long-term and integrated strategies for achieving key goals in the context of climate change:
- National Solar Mission
- National Mission for Enhanced Energy Efficiency
- National Mission on Sustainable Habitat
- National Water Mission
- National Mission for Sustaining the Himalayan Ecosystem
- National Mission for a “Green India”
- National Mission for Sustainable Agriculture
- National Mission on Strategic Knowledge for Climate Change
The occurrence of floods and droughts, heat and cold waves are occurring across the world due to climate change. Their adverse impact on the livelihood of farmers is tremendous. It is more so in India as our economy is more dependent on Agriculture. Interestingly, weather extremes of the opposite in nature like cold and heatwaves and floods and droughts are noticed within the same year over the same region or in different regions and likely to increase in ensuing decades. Human and crop losses are likely to be heavy, as the sea level is rising and Polar Ice caps are melting. The whole climate change is associated with increasing greenhouse gases and human-induced aerosols and the imbalance between them may lead to uncertainty even in year-to-year monsoon behavior over India and other countries as well. Therefore, there should be a determined effort from developed and developing countries to make industrialization environment friendly by reducing greenhouse gases pumping into the atmosphere and taking efforts towards sustainable future.
To quote Barack Obama, former US president,
“We are the first generation to feel the effect of climate change and the last generation who can do something about it.”
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