From UPSC perspective, the following things are important :
Prelims level : El Niño, IOD, Climate change, Water stress
Mains level : Water and climate change crises in India and food, water, and ecological security
What’s the news?
- Disruptive weather events, including El Niño and changing precipitation patterns, are impacting India’s agriculture, resulting in reduced crop yields, water stress, and rising food prices.
- India has experienced a series of disruptive weather and climate phenomena in recent times, highlighting the complexity of our precipitation system. This complexity poses significant challenges to the sustainability and resilience of development projects in the mountains and floodplains.
How do western disturbances influence India’s climate?
- Origin: Western disturbances are weather systems that originate in the Mediterranean region and travel eastward towards South Asia, including India.
- Winter and Spring Impact: During the winter and spring seasons, these disturbances bring much-needed moisture to the western Himalayan region and parts of northern India. This moisture contributes to rainfall and snowfall in these areas, which are essential for agriculture, water resources, and ecosystems.
- Unusual Behavior: The Western disturbance typically follows a seasonal pattern, but in some years, it can exhibit unusual behavior. For example, it may persist late into the summer months, affecting weather patterns beyond its usual timeframe.
- Impact on Southwest Monsoon: When a Western disturbance lingers into the summer, it can influence the southwest monsoon, which is crucial for India’s agriculture. The interaction between these weather systems can lead to unpredictable and sometimes extreme weather events, including heavy rainfall, landslides, and flooding.
- Concerns: The unusual behavior of the Western disturbance can raise concerns about the sustainability and resilience of development projects in regions affected by these weather events, such as the western Himalayan region and northern India.
El Niño’s Influence on Monsoons
- El Niño:
- El Niño is a climate phenomenon characterized by the warming of sea surface temperatures in the eastern and central tropical Pacific Oceans.
- This warming disrupts normal atmospheric circulation patterns, leading to significant climatic impacts worldwide.
- Impact on the Southwest Monsoon:
- El Niño events can influence the Indian Southwest Monsoon, which is responsible for the majority of India’s annual rainfall.
- While not all El Niño events have adverse effects on the monsoon, their intensification can lead to drier conditions in some parts of India.
- El Niño tends to weaken the monsoon, reducing the amount and distribution of rainfall.
- Interaction with Indian Ocean Dipole (IOD):
- The relationship between El Niño and the monsoon has evolved over time.
- In some cases, when El Niño affects the monsoon, another climate phenomenon in the Indian Ocean, known as the positive-phase IOD, can balance the consequences.
- The IOD can influence monsoon variability and rainfall patterns, either mitigating or exacerbating the impact of El Niño.
- Predictive Value of Models:
- Dynamic regression models have suggested that a significant portion of the inter-annual variability of the Southwest Monsoon can be attributed to the combined effects of El Niño and the IOD.
- This indicates the predictive value of these models in understanding and forecasting monsoon behavior during El Niño events.
- Food Security Implications:
- El Niño’s influence on the monsoon has direct implications for food security in India.
- Reduced monsoon rainfall can delay the onset of rains, affect crop sowing, and result in hot temperatures that negatively impact crop growth and soil moisture.
- Crop yields, especially for water-intensive crops like rice and soybean, can be significantly affected during El Niño years, leading to food production challenges.
How are agriculture and water dependency intricately linked in India?
- Two Types of Water for Agriculture:
- Agriculture in India relies on two primary sources of water: green water and blue water.
- Green water refers to rain-fed soil moisture that is utilized by crops and eventually transpires into the atmosphere.
- Blue water includes the water found in rivers, lakes, reservoirs, and groundwater, which is essential for irrigation as well as drinking and industrial use.
- Importance of Green Water:
- Despite significant investments in dams, reservoirs, and irrigation systems, approximately half of the cultivated area in India depends on green water.
- Green water is crucial for rainfed agriculture, as it provides moisture for crops and contributes to the overall water availability for agriculture.
- Water Requirements for the Daily Diet:
- The daily diet of individuals in India, from cooking oil to diverse foods, is associated with a substantial water footprint.
- On average, an individual’s daily diet in India requires approximately 3,268 liters of water per day, subject to regional variability.
- A significant portion (about 75%) of this water footprint is attributed to green water, highlighting the importance of rainfed agriculture to food and nutritional security.
- Dependency on Green Water in Irrigated Areas:
- Even in areas with access to irrigation, many dominant crops still depend on green water to varying degrees.
- For example, during the kharif season, rice paddy under irrigation uses green water for about 35% of its water requirements.
- Staple crops like tur dal, soybean, groundnut, and maize also rely considerably on green water, particularly during specific growing seasons.
- Impact of Climate Phenomena on Green Water:
- Climate phenomena like El Niño can disrupt the availability of green water by delaying the start of rains and affecting sowing schedules.
- Higher temperatures during El Niño events may negatively influence plant growth and soil moisture, impacting crop yields.
- Food Production Challenges:
- During El Niño years, when green water availability may be compromised, crop production can be significantly affected.
- For instance, there was a 28% decline in soybean production in India during the 2015–2016 El Niño year compared to the average
Central India’s vulnerability
- Geographic Region:
- Central India comprises 36 districts across the states of Madhya Pradesh, Chhattisgarh, and Maharashtra.
- This region is characterized by diverse landscapes, including highlands and urban centers.
- Climate Change Hotspot:
- Central India is identified as a climate change hotspot due to its critical role in water, food, and ecological security.
- The region includes headwaters for five of India’s 10 major river basins, making it crucial for water resources.
- Water Stress:
- Central India experiences significant and persistent water stress.
- Water stress is driven primarily by the demand for irrigation, particularly during the rabi season, which relies on blue water sources such as rivers and reservoirs.
- Extent of Water Stress:
- Approximately 70–78% of the landscape in Central India experiences water stress for four or more months each year.
- Among the 17 urban centers in the region, 11 face water stress for six to eight months, with Nagpur enduring water stress for the longest duration.
- Changing precipitation patterns, including declining monsoon precipitation since the 1950s, have exacerbated water stress in Central India.
- Diversifying Agro-Food Systems:
- To adapt to changing precipitation patterns and water availability, there’s an emphasis on diversifying agro-food systems.
- This includes shifting away from water-intensive crops to alternative, less water-dependent crops like millets.
- Reducing Dependence on Water-Intensive Crops:
- A key adaptation strategy is reducing dependence on water-intensive crops, particularly during periods of water stress.
- Crop diversification may involve promoting the cultivation of millets and alternative varieties of dominant cereals.
- Shorter growing cycles:
- Advisories to farmers may include shifting to crops with shorter growing cycles.
- Shorter growing cycles can help adapt to changing precipitation patterns and mitigate the risks associated with extended dry periods.
- Improved Forecasting and Early Warning Systems:
- Adaptation efforts are aided by advancements in short-term weather forecasting and early warning systems.
- Timely weather forecasts and warnings for intense rain and dry spells can help farmers make informed decisions.
- Enhancing Reservoir and Dam Management:
- Given the risks associated with extreme rain events, adaptive strategies include improved management of dams and reservoirs.
- Effective reservoir and dam management can reduce the risk of dam-based flood disasters.
- Balancing Water Demands:
- Sustainable water-sharing practices between humans and nature are crucial for adaptation.
- Balancing the needs of agriculture, industry, and ecosystems while maintaining ecological flows in rivers is a priority.
- Government Initiatives:
- Both the central and state governments are involved in implementing adaptation strategies.
- Government efforts may include policy support, incentives for farmers, and investments in infrastructure.
- The water and climate change crises in India, intertwined with food, water, and ecological security, require a multifaceted response. Diversifying agro-food systems, reducing dependence on blue water, rejuvenating rivers, and sustainable water sharing between humans and nature are essential for the well-being of India’s 1.4 billion people.