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  • Mount Marapi Eruption in Indonesia

    Why in News?

    Mount Marapi, one of Indonesia’s most active volcanoes, erupted again, sending an ash column about 2 km high into the sky over West Sumatra’s Tanah Datar District. Authorities continue to enforce a 3 km exclusion zone around the volcano.

    Note: This volcano is Mount Marapi (West Sumatra), not Mount Merapi (Central Java). They are two different active volcanoes in Indonesia.

    Key Highlights

    • The eruption produced an ash plume reaching approximately 2 km above the summit.
    • A 3 km exclusion zone remains in force following the deadly eruption in December 2023.
    • Authorities have advised residents and tourists to stay away from the crater due to the risk of further eruptions.
    • Indonesia frequently experiences volcanic eruptions because of its tectonic setting.

    About Mount Marapi

    • Located in West Sumatra Province, Indonesia.
    • Elevation: 2,891 metres.
    • It is one of the most active volcanoes in Sumatra.
    • It is a stratovolcano (composite volcano) characterized by frequent explosive eruptions.

    What is a Stratovolcano?

    • A stratovolcano is formed by alternating layers of lava, volcanic ash, and pyroclastic material.
    • It has steep slopes and is associated with explosive eruptions because of silica-rich, viscous magma.
    • Examples include Mount Fuji (Japan), Mount Merapi (Indonesia), and Mount St. Helens (USA).

    Why is Indonesia Highly Prone to Volcanic Activity?

    • Indonesia lies on the Pacific Ring of Fire, a zone of intense volcanic and seismic activity.
    • It is located at the convergence of the Indo Australian, Eurasian, Pacific, and Philippine Sea tectonic plates.
    • The country has more than 120 active volcanoes, the highest number in the world.

    Prelims Facts

    • Pacific Ring of Fire contains about 75% of the world’s active volcanoes and experiences nearly 90% of global earthquakes.
    • Volcanic hazards include ashfall, lava flows, pyroclastic flows, volcanic gases, and lahars (volcanic mudflows).

    [2024] Consider the following:
    1. Pyroclastic debris
    2. Ash and dust
    3. Nitrogen compounds
    4. Sulphur compounds
    How many of the above are products of volcanic eruptions?

    [A] Only one

    [B] Only two

    [C] Only three

    [D] All four

  • Behind Europe’s heatwave, cliamte change the culprit

    Why in the News?

    A World Weather Attribution (WWA) study has confirmed climate change as the unequivocal cause of the ongoing European heatwave, which has broken or is forecast to break historic heat-stress records in 45% of 854 cities analysed. The finding sharpens a wider gap between the certainty climate science now offers and the declining political priority accorded to climate action.

    What does the WWA study establish about the causal role of climate change in the current heatwave?

    1. Unequivocal attribution: WWA found climate change, not the El Niño phenomenon or any other factor, responsible for the European heatwave.
    2. Recurrence pattern: This is the third severe heatwave to grip Europe in five years, after 2022 and 2023.
    3. Mortality scale: More than 1,300 excess deaths have been recorded since 21 June; over 1,00,000 people are estimated to have died from extreme heat across 2022 and 2023.
    4. Probability shift: Record-breaking night-time highs are nearly 100 times more likely now than in 2003; daytime peak temperatures are nearly 10 times more likely.
    5. Historical baseline broken: Temperature records being broken were set in 1976; the current daytime and overnight highs would have been virtually impossible to occur as recently as 1976.
    6. ENSO ruled out: The El Niño Southern Oscillation phase played no role in driving the heat during this spell.

    Why has climate attribution science become central to fixing responsibility for extreme weather events?

    1. Definition: Climate attribution is the scientific discipline that determines how much human-caused global warming influences the probability and intensity of specific extreme weather events. It quantifies how much worse or more likely a particular flood, heatwave, or drought has become compared to a hypothetical world without human-driven emissions
    2. Function: Attribution science tests the likelihood of a specific extreme weather event occurring if climate change were not taking place.
    3. Recency: The discipline has developed only over the last two decades.
    4. Speed gain: Assessments earlier took months or years; WWA’s methods now produce findings within days, even while an event is still ongoing.
    5. Purpose: The science removes ambiguity and fixes the exact extent of climate change’s responsibility for an event.
    6. Scientific caution without it: Scientists are otherwise wary of linking any individual extreme weather event to climate change without a dedicated attribution study.
    7. Policy intent: Beyond generating evidence, attribution studies are designed to force policymakers to act faster on climate change.

    Does scientific certainty on climate attribution translate into proportionate political action?

    1. Evidence-action gap: Scientific evidence on climate change is already voluminous and compelling, yet climate change has dropped down the list of global priorities.
    2. Political trigger: The decline has sharpened particularly after Donald Trump took office as US President.
    3. Forum evidence: Recent G7 meetings have carried little or no climate-related agenda or outcomes.
    4. Reversal of salience: Climate change was earlier among the most prominent items at international meetings involving influential leaders; this prominence has receded.
    5. Target abandonment: Scientists maintain the Paris Agreement targets of containing global temperature rise within 1.5°C to 2°C remain achievable, but governments treat them as effectively out of reach.
    6. Reframing of feasibility: Governments are treating the required resource mobilisation as politically impractical rather than scientifically unattainable.

    What risk does the global shift from mitigation to adaptation pose?

    1. Strategic shift: Countries are increasingly choosing to let climate change play out and to adapt to its impacts rather than prevent it.
    2. Scientific objection: Scientists routinely warn against adaptation as a substitute for mitigation.
    3. Inherent limits: Adaptation has limits beyond which impacts cannot be absorbed.
    4. Trend trajectory: Events such as the European heatwave are projected to increase in both frequency and intensity over coming years.
    5. Displacement, not resolution: The shift to adaptation transfers the climate risk from prevention to adaptation capacity rather than resolving it.

    Conclusion

    Climate attribution science has removed the scientific ambiguity once used to avoid linking individual extreme weather events to climate change. The European heatwave attribution exposes a widening gap between scientific certainty and political will, as global climate governance deprioritises mitigation. Countries are substituting adaptation for prevention despite scientists’ warnings that adaptation carries inherent limits. Closing this evidence-action gap is now central to achieving the Paris Agreement targets.

    PYQ Relevance

    [UPSC 2017] ‘Climate Change’ is a global problem. How India will be affected by climate change? How Himalayan and coastal states of India will be affected by climate change?

    Linkage: The PYQ xamines the impacts of climate change and the need for mitigation and adaptation strategies. The article uses the European heatwave as scientific evidence that climate change is intensifying extreme weather events and highlights the growing gap between climate science and political action.

  • Venezuela Earthquake

    Why in News?

    A powerful doublet earthquake (Magnitude 7.2 followed by 7.5) struck Venezuela, killing over 188 people and injuring more than 1,500. It is the strongest earthquake to hit Venezuela in 126 years.

    Key Highlights

    • Two major earthquakes struck within one minute, making it a doublet earthquake.
    • Epicentres were located west of Caracas, near the coastal town of Morón.
    • Tremors were felt in Colombia and Brazil.
    • The earthquakes occurred at shallow depths (10 km and 22 km), resulting in severe ground shaking.
    • International humanitarian assistance was offered by India, the United States, the United Nations, China, Brazil, and others.

    Why Did the Earthquake Occur?

    • Plate Boundary: Venezuela lies along the boundary between the Caribbean Plate and the South American Plate.
    • Strike-slip Faulting: The Caribbean Plate moves eastward relative to the South American Plate, causing horizontal movement along faults.
    • Active Fault Zone: The earthquake occurred near the El Pilar Fault System, one of the most active fault systems in northern Venezuela.
    • Shallow-focus Earthquake: Shallow earthquakes release energy close to the Earth’s surface, leading to greater destruction.
    • Doublet Earthquake: Two large earthquakes occurring almost simultaneously amplify structural damage.

    Prelims Pointers

    • Earthquake: Sudden release of energy in the Earth’s crust due to movement along faults.
    • Focus (Hypocentre): Point inside the Earth where an earthquake originates.
    • Epicentre: Point on the Earth’s surface directly above the focus.
    • Shallow-focus earthquakes: Depth less than 70 km; generally cause maximum damage.
    • Strike-slip fault: Fault where two blocks move horizontally past each other.
    • Doublet earthquake: Two major earthquakes of similar magnitude occurring close together in time and location.

    [2023] Consider the following statements :
    1. In a seismograph, P waves are recorded earlier than S waves.
    2. In P waves, the individual particles vibrate to and fro in the direction of wave propagation whereas in S waves, the particles vibrate up and down at right angles to the direction of wave propagation.
    Which of the statements given above is/are correct?

    [A] 1 only

    [B] 2 only

    [C] Both 1 and 2

    [D] Neither 1 nor 2

  • In dry monsoon, a test of resilience

    Why in the News?

    India’s 2025 monsoon season is forecast to be the weakest in a decade, with 77% of the country’s land area already recording more than 20% rainfall deficit as of June 24. The season has exposed a structural tension: India’s agricultural and energy systems remain deeply dependent on monsoon rainfall. At the same time, the government’s own investments in renewables, rainwater harvesting, and rural employment infrastructure suggest the country may now be better placed to absorb the stress than in any previous deficit year.

    What Has Made the 2025 Deficit Structurally Different from Past Deficits?

    1. Scale of the deficit: As of June 24, 537 of 740 districts recorded over 20% rainfall deficit. Only eight of 36 States/UTs showed no deficiency. IMD forecast low to moderate rainfall across nearly half of India’s landmass.
    2. El Niño is not the primary cause: El Niño emerged in early June, too late to explain the June deficit because its impact on the Indian monsoon occurs with a lag. The dominant driver is the Madden Julian Oscillation (MJO).
    3. MJO as the proximate driver: A moving system of winds and clouds that alternately enhances or suppresses rainfall. In June, its rain-suppressing phase remained over India, with a shift expected in early July.
    4. June is ordinarily a high-rainfall month: IMD had forecast at least 92% of the Long Period Average (LPA) rainfall for June. The actual deficit of over 40% marks a significant departure from expectations.
    5. The La Niña lag: La Niña’s favourable impact on the Indian monsoon also occurs with a lag and was unlikely to influence June rainfall. This raises the possibility of a drier-than-expected monsoon season.

    What Is the Nature of India’s Dependence on the Monsoon and What Has Reduced It?

    1. The baseline dependence: The southwest monsoon provides nearly 75% of India’s annual rainfall. It supports irrigation, groundwater recharge, reservoirs, hydropower, agriculture, food security, rural incomes and economic growth.
    2. Infrastructure investments over a decade: India has expanded irrigation, rainwater harvesting, water storage and conservation. Official reports also show improving groundwater levels.
    3. Renewable energy as the decisive structural shift: Solar and wind power have reduced dependence on hydropower, which relies on reservoir storage. This helps preserve water for irrigation and drinking purposes.
    4. The residual dependence: Better resilience reduces stress but does not eliminate the need for planning and policy intervention.
    5. Rural employment as a demand buffer: MGNREGS has created water conservation and storage assets while providing income support to rural households during rainfall deficits, helping stabilise rural demand.

    What Existing Strengths Make Absorption of the 2025 Deficit Possible?

    1. Major reservoirs at good storage levels: Good rainfall over the last two years has kept reservoir storage comfortable, reducing immediate pressure on irrigation, drinking water and hydropower.
    2. Improvement in groundwater situation: Better groundwater levels provide an additional irrigation source where reservoir supplies become constrained.
    3. Renewable energy reducing reservoir pressure: Expansion of solar and wind power lowers dependence on hydropower, allowing reservoirs to conserve water despite weak monsoon inflows.
    4. Pre-monsoon rainfall altering farmer behaviour: Early forecasts encouraged many farmers to sow kharif crops using pre-monsoon showers, reducing exposure to the subsequent rainfall deficit.
    5. The limits of absorption: Resilience has improved but remains incomplete, requiring continued policy intervention.

    Where Does Resilience End and Vulnerability Begin? 

    1. The central tension: India has strengthened resilience, but climate change is making monsoon deficits more frequent, prolonged and unpredictable, testing existing adaptation measures.
    2. Quantitative unpredictability now exceeds planning assumptions: Climate change is making even good monsoon years less predictable, weakening the idea of a stable “normal monsoon.” The 2025 deficit could represent a recurring pattern rather than an exception.
    3. Hydropower remains a structural vulnerability: Solar and wind reduce dependence on hydropower but cannot replace it entirely. Reservoir shortages during weak monsoons can still affect electricity generation and grid stability.
    4. Agricultural productivity remains rainfall-sensitive: Investments in water conservation reduce drought impacts but cannot fully break agriculture’s dependence on monsoon performance, leaving food security vulnerable during prolonged deficits.
    5. Rural demand suppression risk persists: Poor monsoons lower farm incomes and rural demand. MGNREGS mitigates this impact but cannot fully offset a season-long rainfall deficit.

    What Must India Do That It Has Not Yet Done?

    1. The policy direction is defined: Developing greater climate resilience remains the only long-term solution, as monsoon behaviour cannot be controlled
    2. Quantitative rainfall forecasting must improve: More accurate district-level and sub-seasonal forecasts are essential for planning crop calendars, reservoir operations and water storage.
    3. The transition from input-side to output-side resilience: Investments in storage, groundwater recharge and renewables must translate into stable farm output, rural incomes and food prices during rainfall shocks.
    4. Climate adaptation must be recalibrated to current trajectories, not historical averages: Adaptation must continuously evolve because climate conditions are changing faster than the historical benchmarks used for planning.

    Conclusion

    India’s improved groundwater levels, major reservoir storage, and renewable energy capacity mean that a decade-worst monsoon need not produce a decade-worst crisis. However, the reduction in monsoon dependence is partial. Hydropower reliance persists, agricultural productivity remains rainfall-sensitive, and climate change is making deficits more frequent, longer, and harder to predict. Resilience built for last decade’s weather is already being outpaced by this decade’s climate.

    PYQ Relevance

    [UPSC 2023] Why is the South-West monsoon called ‘Purvaiya’ (easterly) in Bhojpur Region? How has this directional seasonal wind system influenced the cultural ethos of the region?

    Linkage: The PYQ tests understanding of the South-West Monsoon and its significance. The article moves beyond monsoon mechanics to examine how changing monsoon behaviour is reshaping India’s climate resilience.