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GS Paper: GS1-14.Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc.,

  • 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

  • What is a twister? Why are the majority of twisters observed in areas around the Gulf of Mexico?

    Key Features of a Twister

    Funnel-shaped cloud – Visible condensation funnel extending downward.

    Very high wind speeds – Can exceed 300 km/h (EF5 category).

    Short duration – Typically lasts minutes but causes intense damage.

    Narrow path of destruction – Damage track often a few hundred meters wide.

    Associated with supercell thunderstorms

    Low pressure core – Central pressure drop causes debris uplift.

    Occurs mostly in mid-latitudes – Especially continental interiors.

    Formation Process of a Twister

    Warm, moist air near the surface rises rapidly.

    Cold, dry air above descends below.

    Wind shear develops – Change in wind speed and direction with height.

    Horizontal rotation forms in the lower atmosphere.

    Updraft tilts rotation vertically, forming a mesocyclone.

    Supercell thunderstorm develops.

    A funnel cloud forms and extends to ground, becoming a tornado.

    Reasons for Majority of Twisters Around the Gulf of Mexico

    Continuous supply of warm, moist air – Gulf waters average 25-30°C.

    Collision of contrasting air masses – Warm Gulf air meets cold Canadian air over central U.S.

    No Latitudinal Barriers- Unlike Europe’s Alps, North America has no east-west mountain ranges to block the collision of these contrasting air masses.

    Low-Level Jet Streams from the Gulf provide the necessary wind shear to initiate rotation near the ground.

    Dryline effect – Dry air from Rockies creates a sharp moisture gradient leading to storm development.

    The Great Plains and Mississippi Valley offer a smooth “runway” that prevents the disruption of rotating storm structures.

    Proximity to Tornado Alley – Central U.S. records ~75% of world’s tornadoes.

    The high frequency of thunderstorms in the gulf region creates tornados. 83% of Gulf hurricanes since 1950 have produced at least one tornado.

    As climate variability enhances the frequency and intensity of tornados, advanced radar detection and robust disaster preparedness is needed for disaster risk reduction.