Environment

Glacier Ice Algae accelerating Greenland Ice Sheet melting

Context: Recent studies highlight the role of dark-pigmented microalgae in intensifying Greenland Ice Sheet melting process, which is a critical contributor to global sea-level rise.

Relevance of the Topic: Prelims: Trends in Climate Change- Greenland Ice Sheet, Glacier ice algae. 

About Greenland Ice Sheet

  • Greenland Ice Sheet contains the equivalent of 7.4 meters of global sea level rise, currently frozen atop the world’s largest island.
  • Greenland Ice Sheet gains mass chiefly from snow accumulation, and loses mass through meltwater runoff and discharge of solid ice into the ocean.
    • It has experienced net-annual mass loss for 27 years, every year since 1998. 
    • The melting of the Greenland Ice Sheet is the single largest contributor of freshwater to global sea-level rise.
  • Ice sheet mass loss affects human and natural environments worldwide through:
    • Coastal erosion
    • Saltwater intrusion
    • Habitat loss
    • Heightened storm surges
    • Tidal flooding
    • Permanent inundation 

About Glacier Ice Algae: 

  • Glacier algae are dark-pigmented microalgae capable of surviving extreme glacier environments. 
  • This algae plays a significant role in altering the surface properties of Greenland Ice Sheet, contributing to accelerated melting.
    • The algae grows on melting glacier and ice sheet surfaces across the cryosphere. This causes the ice to absorb more solar energy and consequently melt faster. 
    • This also results in cycling of carbon and nutrients within the ecosystem.  
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Key findings of the study

  • Efficient nutrient uptake: 
    • The microalgae possess an extraordinary ability to absorb essential nutrients such as carbon, nitrogen, and phosphorus at high rates. 
    • This efficiency allows them to sustain growth even in environments with limited nutrient availability.
  • Adaptation mechanism: 
    • The algae’s survival strategy involves maintaining high carbon-to-nutrient ratios and storing phosphorus internally. 
    • This adaptation is crucial for thriving on the nutrient-poor glacier surfaces, where traditional nutrient sources are scarce.
  • Expansion potential: 
    • As the Greenland Ice Sheet continues to melt, more bare ice is exposed, providing new surfaces for colonisation. 
    • The algae’s ability to persist without significant external nutrients enables them to rapidly expand their coverage, further intensifying the melting process.
  • Albedo reduction: 
    • The dark pigmentation of the algae significantly decreases the reflectivity (albedo) of the ice surface. 
    • With less sunlight reflected back into the atmosphere, more heat is absorbed, leading to a higher rate of ice melting.
  • Melt rate amplification: 
    • Algal blooms along the western margin of the ice sheet have been shown to increase melt rates by 10 to 13%. 
    • This substantial contribution underscores the critical role of biological factors in the ice sheet’s mass loss.

Environmental and Climatic Implications

  • Sea-level rise: The enhanced melting driven by algal colonisation adds to the volume of freshwater entering the oceans, directly contributing to global sea-level rise. 
  • Climate modeling: The study emphasises the necessity of incorporating biological processes, such as algal growth and spread, into climate models that predict ice sheet melt. 
  • Urgency in mitigation: Understanding the biological drivers of ice melt is crucial for formulating effective climate mitigation and adaptation strategies. 

Global Sea Ice Cover has dipped to Record Low

Context: As per the data from US National Snow and Ice data Center (NSIDC), the combined extent of Arctic and Antarctic sea ice dropped from 15.93 million sq km to 15.76 million sq km in marking a record low. 

Relevance of the Topic: Prelims: Questions based on climate change and climatology. 

About Sea Ice Cover

  • There are two major sea ice spots in the world, the Arctic and Antarctic. Arctic sea ice covers 40% of total global sea ice. Whereas, Antarctic sea ice accounts for 60% of total global sea ice due to its extensive seasonal fluctuation.
  • Role of sea ice in maintaining climate: 
    • Enhancing albedo: The white ice helps in reflecting back the insolation, enhancing albedo. This helps in maintaining the global temperature.
    • Absorbing heat: The sea ice absorbs the subsurface heat in the ocean. This reduces the average ocean temperature.
    • Prevents ocean acidification: By reducing the ocean temperature, sea ice cover helps in reducing the carbonification of ocean water. This in turn helps in maintaining health of corals, across the globe.

Extent of ice dip in Arctic and Antarctic (As per the study)

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  • According to the NSIDC, an estimate of 77,800 sq km of ice has been lost per year since the late 1970s.
  • Arctic: Between 1981 and 2010, Arctic sea ice extent in September (when it reaches its minimum) shrunk at a rate of 12.2% per decade. 
  • Antarctica: Until 2015, the region actually witnessed a slight year-on-year  increase in sea ice. But, between late 2014 and 2017 the Antarctic lost two million square km of sea ice, i.e., an area equivalent to roughly four times the size of Spain. 
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Reasons behind the dip: 

  • Oceanic and Atmospheric changes: The studies suggested the subsurface warming of the Southern Ocean has pushed the Antarctic sea ice melt. 
  • Transformed wind pattern: Changes in the wind patterns can influence sea ice extent by pushing warmer water. The transformed wind pattern in the Arctic, sea ice remained low because of the delayed freezing around the Hudson Bay. 
  • Increased ocean heat loss: Less ice means more open ocean, which accelerates further melting of ice, due to rise in absorption of heat.
  • Storms and higher air temperature: The regions like the Barent sea witnessed some storms due to which the Arctic ice has become thinner and more fragile over the years. Also, higher than usual air temperatures in areas such as Svalbard, Norway resulted in further loss of sea ice.

Implications of sea ice loss

  • Climate regulation: Antarctica sea ice plays a crucial role in regulating earth’s climate by reflection. A decrease in the sea ice alters these dynamics, potentially accelerating global warming.
  • Ecosystem impact: The loss of ice affects the habitat of various polar species (like Polar Bear and Penguins), disrupting food chains and threatening biodiversity.
  • Sea level rising: While sea ice melt does not directly contribute to sea level rise leading to further vulnerability and climate change induced migration. (E.g., Indonesia changed its capital from Jakarta due to the threat of sea level rise.)

Understanding the contributing factors for dip in ice cover and its potential consequences is essential for developing effective mitigation and adaptation strategies. 

Translocation of African Cheetahs: Neither Ecologically Sustainable nor Ethical

Context: A new study by the Centre for Wildlife Studies (which examines the ethical, ecological and welfare challenges associated with the translocation of African cheetahs to India) has expressed concern over the translocation of the animals.

Relevance of the topic:

Prelims: Key facts about Cheetah; Project Cheetah 

Mains: Conservation of keystone species: Significance and challenges. 

Major Highlights: 

  • The study highlights that the translocation of African cheetahs to India has resulted in significant challenges:
    • High mortality rate of 40%-50% in the first phase of the project, far below the expected survival rate of 85%.
    • High levels of stress for Cheetahs with over 90 chemical immobilisations and regular veterinary interventions, raises concerns about their physical and mental health.
    • Reliance on a continuous supply of cheetahs from southern Africa, is neither ecologically sustainable nor ethical. African cheetah populations are already under pressure with only around 6,500 mature individuals remaining in the wild.
  • This raises concerns about the scientific rationale and the long-term viability of the Cheetah translocation project (Project Cheetah) in India. 

Project Cheetah (Cheetah Reintroduction in India)

  • Project Cheetah is an initiative to reintroduce cheetahs into the wild after their extinction in the country in 1952. 
  • Initiative of: National Tiger Conservation Authority (NTCA). The Wildlife Institute of India (WII) provides technical assistance, coordinating the reintroduction project. 
  • Under Project Cheetah, so far 20 adult African cheetahs, eight from Namibia in September 2022 and 12 from South Africa in February 2023, were introduced into the Kuno National Park (KNP) in Madhya Pradesh.
  • As of February 2025, 26 Cheetahs survive (including 12 Adults and 14 cubs), and other adult Cheetahs died. There were various causes of their death including starvation and bacterial infection (blood poisoning/septicaemia) due to wounds caused by the tracking radio collar.
  • Under the Cheetah Action Plan, the government is planning to relocate a new batch of Cheetahs from Africa to the Gandhi Sagar Wildlife Sanctuary in Madhya Pradesh.

About Cheetah

  • The cheetah is a large cat and the world’s fastest land animal.
  • Characteristics:
    • They have a slender body with long legs, a small round head, and distinctive black spots on their tan fur.
    • They are carnivorous animals and hunt mainly small to medium-sized antelopes such as gazelles and impalas.
    • They inhabit diverse scrub forests, dry grasslands, savannas and other arid and semi-arid open habitats.
About Cheetah

Distribution of Cheetahs:

  • Historically, Asiatic Cheetahs had a very wide distribution in India (from Punjab to southern Tamil Nadu, Gujarat, Rajasthan to Bengal). In 1952, the cheetah was declared officially extinct in India.
  • Today, four subspecies of Cheetahs are recognised that are native to Africa and Central Iran. (present in fragmented habitats in Iran, Sahara Desert, Tanzania, Namibia, South Africa etc.) 

Threats and Conservation status: 

  • Threats: Habitat loss, conflict with humans, poaching and high susceptibility to diseases. 
  • Protection Status: 
    • IUCN Status: Vulnerable
    • CITES: Appendix I
    • Wild Life (Protection) Act 1972: Schedule II
  • Cheetah Conservation Fund (1990): An international non-profit organization headquartered in Namibia, founded in 1990 for the conservation of cheetahs and their ecosystems.

Significance of conserving Keystone Species:  

  • Cheetahs, a keystone species, have been reintroduced in India owing to their ecological and economic significance.
    • A keystone species helps to keep an ecosystem together and functioning by shaping it in various ways, from being apex predators to ecosystem engineers.
    • Without them, their ecosystems would be dramatically different or even cease to exist. A keystone species is often, but not always, a predator. E.g., Cheetah, Wolf, Sea otters etc.
  • The significance of key stone species conservation includes:
    • Restores degraded ecosystem: Many Keystone species are at the top of the food chain and naturally control the prey base population, thus reducing the pressure on ecosystems. E.g., Cheetahs can restore open forest and grassland ecosystems.
    • Bio-diversity: Keystone species prevent species at lower trophic levels from monopolising critical resources, such as competition for space or key producer food sources, thereby enabling multiple species to survive. E.g., Abundance of sea otters controls sea urchin population, thereby reducing pressure on kelp forest which support diverse fish species.
    • Ecosystem services: Conservation of these species are economically beneficial as they ensure the ecosystems to deliver crucial ecosystem services. E.g., According to the IIFM report, every rupee spent on tiger conservation will yield returns of ₹ 2500 through ecosystem services of tiger reserves such as water provisioning, soil conservation, gene pool protection, tourism etc. 

By revisiting India’s conservation ethos, Project Cheetah aims to revive the lost splendor of the cheetah, contributing to the country’s rich biodiversity and ecological balance.

TrailGuard AI

Context: TrailGuard AI has helped wildlife officials at the Similipal Tiger Reserve, Odisha to arrest 96 poachers and seize more than 86 country-made guns.

Relevance of the Topic: Prelims: Key facts on TrailGuard AI and Similipal Tiger Reserve. 

About TrailGuard AI

  • TrailGuard AI is an end-to-end AI-powered camera-based alert system to enhance wildlife conservation and promote human-wildlife coexistence in remote areas. 
  • It autonomously detects target objects and transmits real-time alerts that can trigger rapid-response. 
  • The TrailGuard system comprises of two units: 
    • The camera unit is of size less than a pen.
    • The battery/communication unit is the size of a notepad. 
    • Both units are connected using a two-metre long cable. 
  • Developed by: Nightjar Technologies, a Gurgaon-based social impact enterprise. 
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Key features of TrailGuard AI: 

  • Compact sized: TrailGuard AI is approximately the size of an index finger that can be easily camouflaged/ installed in areas of interest. 
  • Embedded AI: It has on-board AI that processes images to accurately identify humans, vehicles and wildlife in remote areas or areas of interest. 
  • Real-Time Alert: Upon detecting the target, TrailGuard AI transmits human and wildlife activities in under 30 seconds to designated devices via various networks, enabling real-time interventions. These network transmissions include GSM, long-range radio or satellite, facilitating prompt intervention by authorities. 
  • Extended Battery life of at least 6 months, reduces frequent maintenance and minimizes disturbance to deployment areas. 

Utility- Multiple Use Cases:

TrailGuard AI can be utilised for monitoring:

  • Human-wildlife conflict
  • Wildlife monitoring 
  • Illegal logging in protected areas
  • Mine security
  • Border security
  • Building intrusion monitoring
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About Similipal Tiger Reserve (STR): 

  • The tiger reserve is located in the Mayurbhanj District, Odisha.
  • It is part of the Mayurbhanj Elephant Reserve, which includes three protected areas—Similipal Tiger Reserve, Hadgarh Wildlife Sanctuary and Kuldiha Wildlife Sanctuary.
  • It is surrounded by high plateaus and hills, the highest peak being the twin peaks of Kiriburu and Meghashini. 
  • It derives its name from the abundance of red silk cotton trees (Simul tree) growing in the area.
  • STR along with a 'transitional area' of 2250 sq. km has been a part of the UNESCO World Network of Biosphere Reserves since 2009.
  • It is Asia’s second largest biosphere reserve and India’s only wild habitat for Melanistic Royal Bengal Tigers.
  • Budhabalanga, Salandi and many tributaries of Baitarani river flow from the reserve.
  • Major Fauna: Bengal tiger, Asian elephant, gaur, chausingha.
  • The region around STR is home to various tribes including Kolha, Santhala, Bhumija, Bhatudi, Gondas, Khadia, Mankadia and Sahara. 

Loggerhead Turtles

Context: A research identified various facts and information about the migratory species like Loggerhead turtles. 

Relevance of the Topic: Prelims: Questions based on species, their habitat and their behaviour in the ecosystem.

About Loggerhead Turtles

  • Loggerhead turtle is a species of oceanic turtle found in the Atlantic, Pacific, and Indian Ocean, as well as the Mediterranean Sea.
  • They are named loggerhead turtles for their large heads and powerful jaws that can crush their prey.
  • Key characteristics: 
    • Reddish brown shell and large powerful jaws. 
    • Omnivorous.
    • Temperature dependent sex determination: Warmer temperature produces females and cool temperature produces males.
  • Threats: 
    • Low survival rate i.e., only 1 in 1000 hatchlings will survive to adulthood.
    • Habitat destruction along with the bycatching (accidental capture in fishing net).
  • Conservation status:
    • IUCN status: Vulnerable
    • CITES: Appendix I
    • Wild Life Protection Act, 1972: Schedule I 
  • Conservation efforts: Turtle excluder device in fishing gear, protection of breeding grounds and rescue of captivated turtles.
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Findings of the research: 

  • Loggerhead turtles are known for their large migration routes and often return to feeding sites, even after seasonal journeys and displacements. 
  • The findings suggest that migratory species such as loggerhead turtles use the geomagnetic field (magnetic field of the Earth) as a map and compass, when navigating large distances. 
  • Studies suggest that most vertebrate species could have distinct tools (senses) of magnetoreception, but more research is needed to determine the inner workings of these mechanisms.

Faecal bacteria levels surpass safe limits at Maha Kumbh: CPCB

Context: As per the recent report by the Central Pollution Control Board (CPCB) to the National Green Tribunal, the multiple spots in Prayagraj (where the Maha Kumbh Mela is underway), Uttar Pradesh have failed to meet primary bathing standards due to high levels of faecal coliform in water. 

Relevance of the Topic: Prelims: Key facts about faecal coliform bacteria. 

Major Highlights:

  • According to the CPCB, faecal coliform —a key indicator of sewage contamination— have exceeded the permissible limit of 2,500 units per 100 ml in various spots in Prayagraj. 
  • The high levels of faecal bacteria in the waters pose significant risks of waterborne diseases, while excessive organic pollution threatens aquatic life and overall river health. 

What is faecal coliform bacteria?

  • Coliform is a group of bacteria commonly found in the intestines of warm-blooded animals and humans. Faecal coliform bacteria is present in human or animal wastes. 
  • While not all coliform bacteria are harmful, presence of faecal coliform bacteria in water suggests contamination from sewage or animal waste.
    • They are commonly used as indicators of potential contamination in water.
    • Their presence suggests that the water may also contain other harmful pathogens, such as viruses, parasites, or other bacteria (Salmonella, and E. coli), that originate from faecal matter.
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Implications:

  • Health risks: The pathogens can enter the body via the mouth, nose and ears. Exposure to such contaminated water can lead to a range of health issues, including:
    • Nausea, gastrointestinal infections, vomiting, diarrhoea.
    • Skin rashes and eye irritations.
    • Serious conditions like typhoid and hepatitis A.
    • Respiratory issues due to inhaling water droplets containing bacteria.
  • Individuals with low immune systems, the elderly, and children are most vulnerable. 

Aravali Safari Park Project

 Context: The Haryana state government’s ambitious Aravali Safari Park Project is envisaged to be the world’s largest safari park. However, the project has faced stiff opposition ever since it was first mooted.

Relevance of the Topic:Prelims: Key facts about Aravali Range; Aravali Safari Park Project. 

Aravali Safari Park Project

  • It is an ambitious project of the Haryana government.
  • The project is envisaged to be the world’s largest safari park, which will spread across 3,858 hectare (approximately 10000 Acre) across Gurugram and Nuh districts.
  • The proposed will have animal cages, guest houses, hotels, restaurants, auditoriums, an animal hospital, children’s parks, botanical gardens, aquariums, cable cars, a tunnel walk with exhibits, an open-air theatre and eateries.
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Concerns with the Project

  • Increased tourism in ecologically sensitive area:
    • Experts argue that the project aims at increasing tourist footfall and not conserving the Aravalli mountain range. The increased footfall, vehicular traffic and construction will disturb aquifers under the Aravali hills which are critical reserves for the water-starved districts of Gurugram and Nuh.
  • Legal Protection: 
    • The location of the project falls under the category of “forest”, which is protected under the Forest Conservation Act, 1980. Cutting of trees, clearing of land, construction and real estate development is prohibited on this land.
  • Poor status of Forest in Haryana: 
    • As per the experts, the state has a very low forest cover of 3.6%, and therefore, the State needs rewilding of natural forests and not destructive safari projects.
  • Idea of an Artificial park:
    • Experts questioned the necessity of an artificial park in the lap of nature. According to them, in a natural wildlife habitat like the Aravallis, zoo safari with cages and enclosures does not make sense. 
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Aravali Range

  • It is a mountain range in western India. It is said to be one of the oldest mountain ranges in the world, having its origin in the Proterozoic era.
  • It runs approximately 670 km from north-east to south-west direction. 
  • It starts near Delhi, passes through southern Haryana, Rajasthan, and ends in Gujarat.
  • The system is divided into two sections: The Sambhar-Sirohi ranges and the Sambhar-Khetri ranges.
  • The range gives rise to several rivers, including the Banas & Sahibi (Tributaries of Yamuna), Luni (flows into the Rann of Kutch), Sakhi, and Sabarmati.
  • It is ecologically significant as it combats desertification by checking the spread of the Thar Desert towards eastern Rajasthan.
  • It performs the role of an aquifer with its highly fractured and weathered quality rocks allowing water to percolate and recharge the groundwater.
  • The Aravalli Range is rich in natural resources including minerals such as rock phosphate, lead-zinc-silver, talc, pyrophyllite, asbestos, etc. 
  • Guru Shikhar on Mount Abu is the highest peak of the Aravali range. 

Stubble Burning contributes only 14% PM 2.5 in Delhi-NCR: Study

Context: A study published in the journal Climate and Atmospheric Science highlighted that stubble burning only contributes about 14% of PM 2.5 in Delhi-NCR and is therefore not a primary source of particulate matter concentration in Delhi-NCR. 

Relevance of the Topic: Prelims: Questions based on pollutants like PM 2.5 and PM 10. 

Key Findings of the Study

  • The report claims there is no linear correlation between stubble-burning events in Punjab and Haryana and fine particulate matter  (PM2.5) concentration in Delhi-NCR.
  • It highlighted that PM 2.5 concentration remained stable, despite stubble burning in the Punjab and Haryana declining by over 50% from 2015 to 2023.
  • Contradictory trends: There is a contrast in the stubble burning and concentration of PM2.5 in Delhi-NCR: 
Trend of stubble burningPM2.5 concentration
Stubble burning in Punjab and Haryana declined by 31% and 37% respectively in 2023 compared to 2022.20% increase in PM2.5 (as per sensor at the U.S. Embassy in 2023).
Stubble burning ceased after November.The Air Quality Index in Delhi-NCR in December to February has remained in the ‘very poor’ to ‘severe’ category since 2016.
  • Day and Night variation: The day and night variation of PM2.5 and Carbon Monoxide (CO) points towards other sources of pollution other than stubble burning.
    • Night concentration of PM 2.5 is 20% more as compared to day throughout the year. Whereas, such clear variation is witnessed in Punjab-Haryana during stubble burning months only. This reflects the contribution of other sources in pollution.
    • As such clear variation is observed in Punjab and Haryana during stubble burning months, but in Delhi-NCR such variation is constant throughout the year.
  • Visible reflection of interventions: The reduction in the pollution and improvement in air quality after implementation of Graded Response Action Plan (GRAP) reduced PM 2.5 levels significantly. These stringent transport control and regulation of construction activities underscored the possibility of other major sources of pollutants.
  • Supported by other studies- Another study of IIT Kanpur also supported the claim that stubble burning contributes about 13% PM2.5 and that too only during October and November.
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Other reasons for PM 2.5 apart from stubble burning

  • Alternate pollution sources: Another study of IIT Kanpur has identified that the transport sector is the largest contributor of the PM 2.5 i.e., 30%, followed by local biomass burning (23%), construction industry (10%) and industry (5-7%). These pollutant sources contributed to PM 2.5 in continuous manner.
  • Stagnant winds: The Delhi-NCR region has stagnant winds, lower mixing heights and inversion conditions from the month of December to February intensifies the pollution in the region.
  • Land-locked conditions of Delhi-NCR and delayed mobilisation of pollutants leads to the constant degradation of the air quality in the region.
  • Dip in temperature: Temperature in North India faces a dip from months of November to January. Further, dry conditions during winters intensifies the severity of the pollution.
  • Unsustainable practices: Sectors like constructions follow unsustainable practices by violating the construction by-laws. This further aggravates the condition of pollution in India.
  • Laxed enforcement of laws: Vehicle control and pollution control rules lack proper implementation. Old diesel vehicles and poor monitoring of pollution norms leads to the intensification of PM 2.5 and CO concentration, impacting air quality negatively. 
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About PM 2.5

  • Fine particulate matter (≤2.5 micrometers) suspended in air. 
  • Sources: Vehicle emissions, biomass burning, construction dust, and industrial pollution.
  • Remains airborne for long periods and travels deep into the respiratory system.
  • Direct impacts of persistent exposure to PM2.5:
    • Respiratory Issues: Triggers asthma, bronchitis, lung infections, and reduces lung function.
    • Cardiovascular Diseases: Increases risk of heart attacks, strokes, high blood pressure, and arrhythmia.
    • Neurological Effects: Linked to cognitive decline, memory loss, and increased risk of dementia.
    • Impact on Children & Pregnant Women: Causes low birth weight, preterm births, and hampers lung development in children.
    • Eye & Skin Irritation: Leads to eye redness, itching, and skin allergies.
    • Reduced Life Expectancy: Long-term exposure can cause chronic illnesses, lung cancer, and premature death.

Instead of scapegoating stubble burning, there should be constant enforcement of pollution control laws, promotion of public vehicles and installation of mitigative equipment like Smog towers to reduce the menace of pollution in Delhi-NCR.

strategies for improving AIR quality in Delhi

Climate Risk Index 2025

Context: The Climate Risk Index 2025 published by Germanwatch, an environmental think tank puts India in the top 10 countries most affected by climate change from 1993 to 2022.

Relevance of the Topic: Prelims: Questions based on the findings of Climate Risk Index. 

Key findings about the World

  • Extreme events: There have been more than 9,400 extreme events across the world from 1993-2022. 
  • Life loss: Events like cyclones, droughts and heatwaves have claimed more than 7,65,000 lives in the past three decades.
  • Heatwave claimed the most i.e., 61,778 lives (83% fatalities) in the year 2022, followed by floods and droughts.
  • Droughts affected the most number of people in 2022, i.e., 59% of people in the past three decades. Maximum impact was witnessed in seven nations of Africa. 
  • Economic loss: The extreme climate events have cost more than $4 trillion in the past three decades. Storms followed by floods claimed the highest economic loss in the world.
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Key findings of the report about India: 

  • India ranked 6th in the most affected nation by climate change, whereas, the Dominican Republic is 1st in the ranking, making it the most affected nation from climate change.
  • Risks to India: India has faced various incidents of extreme weather events, including floods, heat waves, cyclones and drought. Floods and landslides resulting from heavy monsoons displaced millions and damaged agriculture. Notable events include;
    • 1998 Gujarat and 1999 Odisha cyclones.
    • Cyclone Hudhud in 2014 and cyclone Amphan in 2020.
    • Uttarakhand floods of 2013.
    • Intense heat waves with temperatures around 50 degree celsius claimed many lives in 1998, 2002, 2003 and 2015.
  • Frequent extreme events: India witnessed more than 400 extreme events in the last three decades.
  • Economic loss: India has faced USD 180 billion loss due to these climate change induced extreme events. 
climate risk index

Teesta Dam and Climate Change

Context: The Union Ministry of Environment, Forest and Climate Change (MoEF&CC) has approved the proposal for rebuilding the Teesta-III dam, despite concerns over its design and stability. The new structure will be a 118.64-metre-tall concrete gravity dam.

Relevance of the Topic: Prelims: Questions based on rivers, tributaries and dams associated.

About Teesta-III Chungthang hydroelectric dam

  • In October 2023, the original 1,200 MW Teesta-III Chungthang hydroelectric dam was destroyed in a flash flood. 
  • The flood was triggered by a Glacial Lake Outburst Flood (GLOF) from the South Lhonak Lake, which washed away the 60-metre-tall concrete dam, claiming 40 lives.
  • Reason for failure of dam: Moraine on the South Lohank lake’s flank suffered a slope failure, weakening the terminus. The failure sent rocks tumbling into the lake generating strong ripple, the event also set off multiple landslides about 30 to 40 kilometers downstream.
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Links between dam failure and global warming: 

  • Reducing albedo: Particulate matter, especially black carbon, also known as soot, reduces the albedo of ice and leads to absorption of solar insolation.
  • Accelerating melting of ice: Global warming and rise in the global average temperature accelerates the melting of ice and glaciers, this leads to the rise in the water levels. (E.g., South Lhonak lake itself was formed in the early 1960s and grew to 167 hectares by 2023)
  • High rate of glacial retreat: Glacial retreat has also been known to destabilise extant geological formations and create new sources of risks.
  • Rise in glacial lakes: As per the Central Water commission, the number of glacial lakes in Himalayan region grew by 10.8% from 2011 to 2024.

Concerns in the construction of Teesta-3 2.0 Dam: 

  • The dam’s design and structural aspects are still pending approval from the Central Water Commission (CWC), the Geological Survey of India, and the Central Soil and Materials Research Station.
  • Reports on the risk assessment fail to account the erosion, sediment transport and riverbank collapse that have a significant impact on the flood behaviour.
  • Local communities and environmental groups like affected citizens of Teesta have highlighted potential risks like Glacial lake outburst floods during project planning stages.

Measures Undertaken

  • Enhanced spillway design: 
    • The dam design is altered from a concrete face rockfill dam (a commonly used structure worldwide) to a concrete gravity dam, a design that relies on its own weight to bear loads. 
    • The company claims that the complete concrete design will lead to a rise in the spillway capacity from 7000 cubic metres per second (cumecs) to 19946 cumecs. This enhancement will offer greater resilience to flash floods and GLOFs.

Suggested Measures: 

  • Development and implementation of a robust Early Warning System (EWS) for flood alerts in the river catchment.
  • Conduct thorough environmental impact assessments (EIA) that incorporate climate change projections, glacial behaviour and potential GLOF risks to inform project design and location decisions.

About South Lhonka Lake

  • South Lhonak lake is a glacial lake in North Sikkim.
  • Formation: The proglacial lake formed due to the retreat of Lhonak Glacier.
  • The National Remote Sensing Center showed a 40% increase in its size over the past three decades.

About Teesta River

  • Origin: Teesta river originates from the Tso Lhamo (lake) in North Sikkim.
  • Course: Flows through Sikkim and West Bengal in India and then enters Bangladesh. Here it merges with Brahmaputra river (known as Jamuna in Bangladesh). The total length is 414 km. 
  • Tributaries: Ranget, Lachung, Lachen and Dikchu rivers.
  • Hydropower project: Teesta-III, Teesta-IV and Teesta-V dams in Sikkim.
  • Water dispute: Teesta water sharing treaty with Bangladesh, a key bilateral agreement that has been pending between the two countries for over a decade.
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NTCA’s concerns on Morand-Ganjal Irrigation Project

Context: The National Tiger Conservation Authority (NTCA) has warned that the construction of the Morand-Ganjal Irrigation Project in Madhya Pradesh will submerge a crucial tiger corridor between the Satpura and Melghat Tiger Reserves. 

Relevance of the Topic: Prelims: Questions based on conservation reserves i.e., Satpura and Melghat Tiger reserve.

About Morand-Ganjal Irrigation Project

  • The project involves a dam on Morand and Ganjal rivers of Madhya Pradesh.
  • The project was proposed in 1972, and got approved in 2017 by the Madhya Pradesh government.
  • Benefits of project: Provide irrigation to 211 villages in Hoshangabad, Betul, Harda and Khandwa districts. The project will provide irrigation to over 52,000 hectares of agricultural land.

Environmental concerns raised by the Project

  • Loss of vital Tiger habitat: The NTCA’s 2022 Tiger Estimation report confirms that the proposed project area is an active tiger habitat.
  • Forest submersion: The dam construction will cause large areas of forest land to be submerged under water, which is a major wildlife corridor between Satpura and Melghat Tiger reserve.
  • Disruption to wildlife movement: Tigers rely on connected forest migration and genetic exchange leading to:
    • Reduced tiger population due to inbreeding, leading to risk susceptibility of pandemic in tiger population
    • Increased human-animal conflict as displaced tigers might enter human population regions.
    • Biodiversity loss, affecting other wildlife leopards, deer and smaller species.

Impact on Indigenous Communities

  • The project will directly displace over 600 members of the Korku tribal community.
    • The Korku tribe is an indigenous community in Central India that depends on forest for food, medical, plants and cultural practice.
  • Loss of livelihood: Displacement will force tribals to leave their ancestral land leading to:
    • Loss of traditional farming methods of tribals.
    • Cultural erosion of tribals as they will be forced to relocate to unfamiliar areas.
  • Social unrest: The possible relocation of tribals due to the project may lead to protests and social unrest.
image 72

Recommendation for the Project

  • Alternative method: NTCA has suggested to the Madhya Pradesh government to explore the alternative site for the project to avoid the negative implications on wildlife.
  • Tiger movement corridor: Alternate tiger movement corridors to be established for fostering the movement of tigers.
  • Redesign project: The project can be redesigned by reducing reservoir size or use tunnel-based irrigation design.
  • Implementing government review steps: The Forest Advisory Committee reviewed the project in 2025 and gave a proposal to divert 2250 hectares of forest land for the project.
  • Rehabilitation of tribals: A fair compensation, alternative housing and providing livelihood training to tribals can help in rehabilitation of the displaced Korku Tribal community.
  • Long-term methods: Promoting eco-friendly methods like micro irrigation, dry land agriculture and agroforestry can help in reducing the requirement of irrigation and promoting water-use efficiency.

About National Tiger Conservation Authority

  • NTCA is a statutory body established in 2005 under the WildLife Protection Act, 1972. 
  • It is the overarching body focused on conservation of tigers in India.
  • NTCA is administered under the Ministry of Environment, Forest and Climate Change (MoEFCC). 
  • Conservation Initiatives by NTCA: 
    • M-STrIPES to monitor tiger movement using technology. 
    • Tiger relocation program to reintroduce tigers to balance population.
    • Community-based conservation by involving communities in habitat protection and sustainable livelihood.

Key facts about Tigers

  • Tiger is an umbrella species. Its conservation automatically ensures the conversation of a large number of flora and fauna and entire ecosystems.
  • India is home to 75% of the global tiger population. 
    • NTCA conducts a tiger census across India every 4 years.
    • As per the latest Tiger Census Report (2022), India has 3682 tigers. (2967 in 2018)
    • Madhya Pradesh has the highest number of tigers (785) in India, followed by Karnataka (563) and Uttarakhand (560). 
  • Conservation status: 
    • IUCN Red List: Endangered
    • Wildlife Protection Act: Schedule 1
    • CITES: Appendix 1

About Mentioned Tiger Reserves

  • Satpura Tiger reserve (Madhya Pradesh)
    • Geographical features: Hilly terrain, deep valet, sandstone peaks and dense forests
    • Vegetation: dry deciduous forest, moist deciduous forests and grassland.
    • Fauna: Bengal Tigers, leopard, sloth bear Indian giant squirrel, gaur and wild dog
    • Rivers: Denwa river (main river), Sonbhadra and Nagdwari river. 
image 73
  • Melghat Tiger Reserve (Maharashtra): 
    • Geographical features include rugged hills, deep gorges and plateaus.
    • Vegetation: Dry deciduous forest, teak dominated forests, and bamboo grooves.
    • Fauna: Bengal tiger, leopard, Indian bison, sambar deer, porcupine, and Malabar pied hornbill
    • Rivers: Tapti (main river), Khandu, Sipna and Gadga river.

A well-planned irrigation project should not come at the cost of tiger conservation and tribal displacement. The government must find a balance to protect both nature and livelihoods.

Marine heat waves

Context: The marine heatwaves (MHWs) off the coastal Western Australia is linked to the death of more than 30,000 fish. Marine heatwaves can happen at different locations in the ocean and have become more frequent and intense over the last few decades.  

Relevance of the Topic:Prelims: Key facts about Marine Heat Waves.

What is Marine Heatwave?

  • A marine heatwave is an extreme weather event. According to India Meteorological Department (IMD), Marine heatwaves are periods of extremely high temperatures in the ocean (above the 90th percentile).
  • It occurs when the surface temperature of a particular region of the sea rises to 3 or 4 degrees Celsius above the average temperature for at least five days. 
  • MHWs can last for weeks, months or even years.
Marine Heatwave

What causes Marine Heatwaves?

  • Marine heatwaves are caused by a range of ocean processes, acting either separately or in combination, but there are two main drivers:
    • Surface heat flux: Heating from the atmosphere, which tends to occur when an atmospheric high-pressure system sits above a region of water for an extended period.
    • Advection: Movement of warmer waters into the region by ocean currents.
  • Marine heatwaves driven by surface heat flux tend to be shallower and shorter in duration, whereas that driven by advection can be deeper and longer in duration.
image 84

What have been the recent trends?

  • In the past few decades, MHWs have become longer-lasting, more frequent, and intense. Their numbers have doubled between 1982 and 2016.
  • IUCN has noticed a rise of 50% in just the last decade.
image 85

How is climate change responsible for this trend?

  • As global temperatures have soared to 1.3 degrees Celsius above the pre-industrial levels, 90% of the extra heat has been absorbed by the ocean. 
  • This has increased the global mean SST by close to 0.9 degrees Celsius since 1850, and the rise over the last four decades is around 0.6 degrees Celsius.

What can be the consequences?

  • Ecosystems: MHWs can have harmful effects on marine ecosystems. For instance,
    • Coral reefs may experience bleaching due to prolonged exposure to high temperatures. 
    • Seagrass beds and kelp forests can also be affected. Impaired photosynthesis, reduced growth, and hindered reproductive functions observed. 
    • Degradation could lead to collapse of local marine food webs, affecting various marine species.
In 2024, coral bleaching on Australia’s Great Barrier Reef reached “catastrophic” levels after intense MHWs put corals under stress. This was the reef’s seventh mass bleaching event.
  • Marine Industries: Fisheries and aquaculture can suffer due to changes in fish distribution and productivity caused by MHWs.
  • Human Activities: Coastal communities and economies can be impacted by disruptions in fishing, tourism, and other ocean-related activities.
  • Rise in weather extremities: Extremely warm waters act as a strong source of heat and moisture, helping cyclones to intensify. About 90% of the cyclones in the north Indian Ocean were preceded by marine heatwaves (1980–2020).
  • Long-Term Effects: Even after the water cools down, the impacts of MHWs can persist for years, affecting marine ecosystems and biodiversity.

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