Background
Sukhna Lake, "nestled at the foothills of the Shivalik Hills in Chandigarh, India, is one of the most beautiful man-made lakes in India". The Ministry of Tourism describes it as "A declared National Wetland, this 3 square kilometre rain-fed reservoir" that "came into existence in 1958 when the Sukhna Choe, a seasonal stream originating from the Shivalik Hills, was dammed". "Architect Le Corbusier, along with Chief Engineer L. Verma, envisioned Sukhna Lake as a serene oasis." Two rules were set to protect it: "motorboats are forbidden on the water, and vehicular traffic is prohibited on the dam's promenade". The roof of the dam serves as the lake's promenade. In winter the lake "becomes a sanctuary for exotic migratory birds such as the Siberian duck, storks, and cranes". It has hosted the Asian Rowing Championships and "boasts Asia's longest channel for rowing and yachting events".
What kind of lake it is:
one of the most beautiful man-made lakes in India
Area and type:
this 3 square kilometre rain-fed reservoir
How the lake was formed:
came into existence in 1958 when the Sukhna Choe, a seasonal stream originating from the Shivalik Hills, was dammed
Wetland status:
A declared National Wetland
Who envisioned it:
Architect Le Corbusier, along with Chief Engineer L. Verma
Winter migratory birds:
exotic migratory birds such as the Siberian duck, storks, and cranes
Why it matters for exams: Sukhna is a standard trap: it looks like a natural lake on a map but is a dammed seasonal stream, and its status as a declared National Wetland links a city water body to India's wetland questions.
Kerala PSCUPSCSSC
In plain words
Choe choe (seasonal hill stream) — A choe is a seasonal stream running down from the Shivalik hills, carrying water mainly in the monsoon.
Rain-fed reservoir rain-fed reservoir — A stored water body that receives no perennial supply and fills only from rainfall run-off in its catchment.
Background
Kaziranga National Park in Assam is on the UNESCO World Heritage List, with a date of inscription of 1985 under natural criteria (ix) and (x), and a World Heritage reference number of 337. UNESCO gives the property area as 42,996 ha. The List's description opens: "In the heart of Assam, this park is one of the last areas in eastern India undisturbed by a human presence. It is inhabited by the world's largest population of one-horned rhinoceroses, as well as many mammals, including tigers, elephants, panthers and bears, and thousands of birds." The statement of Outstanding Universal Value calls it the single largest undisturbed and representative area in the Brahmaputra Valley floodplain, made up of wet alluvial tall grassland interspersed with numerous broad shallow pools fringed with reeds and patches of deciduous to semi-evergreen woodlands. UNESCO credits the park with taking the Indian one-horned rhinoceros from the brink of extinction to the single largest population of the species, and records significant populations of tigers, elephants, wild water buffalo and bears, aquatic species including the Ganges River dolphin, and an important role for migratory birds.
Date of Inscription:
1985
Criteria:
(ix)(x)
Property area:
42,996 ha
World Heritage reference number:
337
Why it matters for exams: Kaziranga is asked about both as a World Heritage property and as rhino habitat, and the Brahmaputra floodplain link explains why its grassland, not forest, is the headline habitat.
Kerala PSCUPSCSSC
In plain words
Alluvial grassland Alluvial grassland — Grassland growing on silt laid down by a river in flood.
Background
The National Tiger Conservation Authority lists Nagarjunsagar Srisailam as the tiger reserve of Andhra Pradesh, the only one shown for the State. In the Authority's table of tiger reserves the entry reads "Nagarjunsagar Sagar", Andhra Pradesh, with a protected area notification year of 1982-83 and a tiger reserve notification year of 2007. Its core area is given as 2,595.72 sq km and its buffer area as 700.59 sq km, for a total area of 3,296.31 sq km. That total is the largest for any tiger reserve in the Authority's table. Assam, by comparison, is shown with four tiger reserves — Kaziranga, Manas, Nameri and Orang — of which Manas is the largest at 2,837.10 sq km total, placing it next after the Andhra Pradesh reserve.
Core area (sq km):
2,595.72
Buffer area (sq km):
700.59
Total area (sq km):
3,296.31
Tiger reserve notification year:
2007
Total area of Manas, Assam (sq km):
2,837.10
Why it matters for exams: "Largest tiger reserve" is asked almost every year, and candidates who remember only the core area get it wrong, because the ranking rests on core plus buffer.
Kerala PSCUPSC
In plain words
Core area Core area — The critical tiger habitat of a reserve, kept free of human use.
Buffer area Buffer area — The surrounding zone of a tiger reserve where regulated human use is allowed.
Background
Great Nicobar is the southernmost island of the Nicobar Islands archipelago, and the Great Nicobar Biosphere Reserve on it is listed by UNESCO's Man and the Biosphere Programme with a Year of nomination of 2013. UNESCO records its Surface as 104,400.00 ha, all of it terrestrial, and says the island covers 103,870 ha of tropical evergreen forest ecosystems. The reserve contains a wide spectrum of ecosystems, including tropical wet evergreen forests, mountain ranges and coastal plains, and Mount Thullier reaches 642 m. About 650 species of angiosperms, ferns, gymnosperms, bryophytes and lichens are recorded, with rare and endemic plants such as the tree fern Cyathea albosetacea and the orchid Phalaenopsis speciosa. In terms of fauna, over 1,800 species are recorded: a total of 14 mammal species, 71 bird species, 26 reptiles, 10 amphibians and 113 fish have been reported, and to date 11 mammals, 32 birds, seven reptiles and four amphibians are considered endemic. Notable endemic or threatened species include the crab-eating macaque, Nicobar tree shrew, dugong, Nicobar megapode, serpent eagle, saltwater crocodile, marine turtles and reticulated python. Like every biosphere reserve under the programme, it is zoned into core, buffer and transition areas.
Year of nomination:
2013
Surface:
104,400.00 ha
Height reached by Mount Thullier:
642 m
Tropical evergreen forest ecosystems covered:
103,870 ha
Vertebrate and fish species reported:
14 mammal species, 71 bird species, 26 reptiles, 10 amphibians and 113 fish
Species considered endemic:
11 mammals, 32 birds, seven reptiles and four amphibians
Why it matters for exams: Biosphere reserves on UNESCO's world network are a recurring list question, and Great Nicobar is the one that carries both an island-geography angle and an endemic-species angle, so a single page of facts answers questions set in the environment section as well as on the map.
Kerala PSCUPSC
In plain words
Biosphere reserve Biosphere reserve — An area recognised under UNESCO's Man and the Biosphere Programme where conservation and local use are managed together through core, buffer and transition zones.
Endemic Endemic species — A species found naturally only in one defined area and nowhere else.
Megapode Megapode — A ground bird that incubates its eggs in a mound of sand and leaf litter instead of sitting on them.
Background
The Andaman and Nicobar Islands is a union territory of India, lying in the Indian Ocean in the southern reaches of the Bay of Bengal and nearer to Indonesia and Thailand than to the Indian mainland. The administration's UT profile records 836 Islands/Islets/Rocky Outcrops in the territory and a Total Area of 8,249 Sq. Km. The territory is made up of two island groups, the Andaman Islands and the Nicobar Islands, which separate the Andaman Sea to the east from the Indian Ocean. The two groups are divided by the 10 degree N parallel, the Andamans lying to the north of this latitude and the Nicobars to the south, and the administration writes that the Andamans and Nicobars are separated by a channel (the Ten Degree Channel) some 150 km wide. The smaller Nicobars comprise some 22 main islands, of which 10 are inhabited. The land area of the Andaman Islands is 6,408 km square and that of the Nicobar Islands 1,841 km square. On how many islands are lived on, the same page carries two figures: its profile table lists Inhabited Islands 31, while its general note says only some 38 are permanently inhabited. The capital is Sri Vijaya Puram, the territory has 03 districts and 09 tehsils, and Hindi and English are the official languages. The administration lists the Andaman Wood Pigeon as the state bird, the Dugong as the state animal and the Andaman Padauk as the state tree.
Total Islands/Islets/Rocky Outcrops:
836
Total Area:
8,249 Sq. Km.
Width of the channel separating the Andamans and Nicobars:
some 150 km wide
Area of the Andaman Islands:
6,408 km
Area of the Nicobar Islands:
1,841 km
Districts:
03
Tehsil:
09
Why it matters for exams: The Ten Degree Channel, the 10 degree N divide and the island and area counts of this union territory are standing map questions in Kerala PSC and UPSC prelims, and the examiner most often tests whether a candidate can place the Andamans to the north and the Nicobars to the south of the channel.
Kerala PSCUPSCSSC
In plain words
Tehsil Tehsil (taluk) — A revenue sub-division of a district, called a taluk in Kerala.
Ten Degree Channel Ten Degree Channel — The sea passage along the 10 degree N parallel that separates the Andaman group from the Nicobar group.
Background
The Cartagena Protocol on Biosafety is a protocol to the Convention on Biological Diversity. It aims to ensure the safe handling, transport and use of living modified organisms (LMOs) resulting from modern biotechnology that may have adverse effects on biological diversity, taking also into account risks to human health. It was adopted on 29 January 2000 and entered into force on 11 September 2003. Its information system is the Biosafety Clearing-House, through which Parties exchange information on living modified organisms. The Protocol covers handling, transport, packaging and identification, unintentional transboundary movements, socio-economic considerations, and public awareness and participation. The Nagoya-Kuala Lumpur Supplementary Protocol on Liability and Redress supplements the Cartagena Protocol, and the Protocol's governing body is the Conference of the Parties serving as the meeting of the Parties to the Protocol.
Adopted:
29 January 2000
Entered into force:
11 September 2003
Parent convention:
Convention on Biological Diversity
Information system:
Biosafety Clearing-House
Why it matters for exams: Which protocol covers biosafety and which covers benefit-sharing is a classic point of confusion in environment questions.
Kerala PSCUPSC
In plain words
LMO Living Modified Organism — An organism altered by modern biotechnology that the Protocol regulates in trade and transport.
Background
The Convention on Biological Diversity (CBD) entered into force on 29 December 1993. It has three main objectives. The first is the conservation of biological diversity. The second is the sustainable use of the components of biological diversity. The third is the fair and equitable sharing of the benefits arising out of the utilization of genetic resources. The Convention's supreme governing body is the Conference of the Parties, supported by a Subsidiary Body on Implementation and a Subsidiary Body on Article 8(j). Its periodic flagship assessment is the Global Biodiversity Outlook, and the International Day for Biological Diversity is observed under it.
Entered into force:
29 December 1993
Main objectives:
3
Supreme governing body:
Conference of the Parties
Why it matters for exams: The three objectives of the CBD, and the year it came into force, are repeatedly asked in environment sections.
Kerala PSCUPSC
In plain words
CBD Convention on Biological Diversity — The global treaty on conserving biodiversity, using it sustainably and sharing its benefits.
Background
Wildlife sanctuaries are legally protected under the Wildlife (Protection) Act of 1972.
The Kerala Forest Department records that Kerala contributes 18 sanctuaries, covering 2156.21 sq km.
India has an extensive network of 573 wildlife sanctuaries spanning 123,762.56 sq km, which is 3.76% of the country's geographical area.
Each sanctuary is managed under a plan that divides its area into a core zone where human interference is prohibited, a buffer zone with controlled human activities, and a tourism zone which lies within the buffer zone itself.
The Choolannur Peafowl Sanctuary safeguards the threatened Grey Junglefowl, and the Kurinjimala Sanctuary protects the endangered Nilgiri tahr and nurtures the Neelakurinji flower, known for its once-in-12-year bloom.
The Thattekad Bird Sanctuary safeguards vulnerable bird species such as the Great Hornbill, while the Mangalavanam Bird Sanctuary represents a coastal mangrove ecosystem.
The Idukki Wildlife Sanctuary provides habitat for the endangered Asian elephant, and the Wayanad Wildlife Sanctuary carries lush rainforest.
The Periyar and Parambikulam sanctuaries are also tiger reserves.
Wildlife sanctuaries in Kerala:
18, covering 2156.21 sq km
Wildlife sanctuaries in India:
573, spanning 123,762.56 sq km
Share of India's geographical area:
3.76%
Governing law:
Wildlife (Protection) Act of 1972
Why it matters for exams: Sanctuary counts and areas for Kerala and India, and the species each sanctuary is known for, are regular environment questions.
Kerala PSCUPSC
In plain words
Core zone Core zone — The undisturbed heart of a sanctuary where human interference is prohibited.
Grey Junglefowl Gallus sonneratii — A threatened wild fowl of peninsular India protected at Choolannur.
Background
The Kerala Forest Department lists Silent Valley, Eravikulam, Anamudi Shola, Pampadum Shola and Mathikettan Shola as the national parks of the State, all regulated under the Wild Life (Protection) Act 1972.
Silent Valley National Park lies in the Nilgiri Hills, is a tropical moist evergreen forest and is watered by the Kunthipuzha River; its endangered fauna include the lion-tailed macaque, the Nilgiri langur and the Malabar giant squirrel.
Silent Valley gained prominence in the 1970s when environmentalists launched the Save Silent Valley movement, which halted a proposed hydroelectric project.
Eravikulam National Park, established in 1978, spans approximately 97 square kilometres in Idukki and Ernakulam districts, in the Kannan Devan Hills.
Eravikulam encompasses Anamudi Peak, the highest point in South India at 2,695 metres, and houses the largest wild population of the endangered Nilgiri tahr.
The mass flowering of Neelakurinji blankets Eravikulam's hillsides once every 12 years, the last bloom having occurred in 2018.
Anamudi Shola National Park covers 7.5 sq km and Mathikettan Shola National Park 12.82 sq km, both declared in 2003 in Idukki district.
Pampadum Shola National Park, declared in 2004, is the smallest national park in the State at 1.32 sq km, and its name translates to the forest where the snake dances.
Mathikettan Shola is a wildlife corridor connecting the Periyar Tiger Reserve and Eravikulam National Park, while Pampadum Shola links Eravikulam with the Palani Hills.
Anamudi Peak:
2,695 metres, the highest point in South India
Eravikulam National Park:
established 1978, about 97 sq km
Smallest national park in Kerala:
Pampadum Shola, 1.32 sq. km
Neelakurinji bloom:
once every 12 years
Why it matters for exams: Park areas, declaration years, Anamudi's height and the Nilgiri tahr and Neelakurinji facts are standard environment questions.
Kerala PSCUPSC
In plain words
Shola Shola — Patches of montane evergreen forest set in high-altitude grassland.
Wildlife corridor Wildlife corridor — A strip of habitat that lets animals move between two larger protected areas.
Nilgiri tahr Nilgiritragus hylocrius — An endangered mountain goat of the Western Ghats and the State animal of Tamil Nadu.
Background
The State of Kerala occupies an area of 38,863 sq. kms of land curving along the Arabian Sea on the south-west coast of India, which is only 1.18 per cent of the total area of India.
The State runs about 590 km in length with the width varying from 32 to 120 km.
Kerala has 44 rivers, 41 west flowing and three east flowing.
The longest river is the Bharathapuzha at 251 km, the Periyar is 228.5 km long and the Pamba 177 km long.
There are 34 big and not so big backwaters in the State, and the biggest backwater is the Vembanad lake, some 200 sq. km in area.
The deltas of the rivers interlink the backwaters and provide water transport in the low lands of Kerala.
The State has three geographical regions, the highlands, the midlands and the low lands, the highlands being dominated by the Sahya Mountains or the Western Ghats.
The south-west monsoon, the major monsoon in Kerala, begins sometime in June-July and continues till August-September, while the north-east monsoon commences in October-November.
The Kerala Legislature records that the land derived its name from Keram, and that a legend credits the warrior-sage Parasurama with reclaiming it from the sea.
Rivers:
44 (41 west flowing, three east flowing)
Longest river:
Bharathapuzha, 251 kms
Backwaters:
34
Biggest backwater:
Vembanad lake, some 200 Sq.km
Area of the State:
38,863 Sq.Kms (1.18 per cent of India)
Why it matters for exams: River counts and lengths, the size of Vembanad and the State's area and extent are among the most frequently asked Kerala facts.
Kerala PSCUPSC
In plain words
Backwater Backwater — A brackish lagoon or lake lying parallel to the coast and linked to rivers and the sea.
Sahya Mountains Sahya Mountains — Another name for the Western Ghats, the range that dominates Kerala's highlands.
Background
Pathanamthitta is the thirteenth revenue district of the State of Kerala.
It nestles its head on the slopes of the Western Ghats and stretches to the low-lying rice fields bordering Alappuzha district.
The district was formed with effect from the 1st November, 1982, vide G.O. (M.S) No.1026/82/RD dated 29.10.1982, with headquarters at Pathanamthitta.
It is bounded on the north by the Changanassery and Kanjirappally taluks of Kottayam district and the Peerumade taluk of Idukki district.
It is bounded on the east by the State of Tamil Nadu.
On the south it is bounded by the Kunnathur, Pathanapuram and Kottarakkara taluks of Kollam district.
On the west it is bounded by the Chengannur, Mavelikkara and Kuttanad taluks of Alappuzha district.
The district administration describes it as abounding with undulating hills, forests, wildlife and valleys.
Position among Kerala's revenue districts:
thirteenth
Formed with effect from:
1st November, 1982
Government Order:
G.O. (M.S) No.1026/82/RD dated 29.10.1982
Headquarters:
Pathanamthitta
Why it matters for exams: The order of Kerala's district formations and district boundaries are standard questions in the State geography section.
Kerala PSCUPSC
In plain words
G.O. Government Order — A written executive order of a State government, cited by number and date.
Revenue district Revenue district — A district as constituted for revenue administration under a District Collector.
Background
Malappuram district, literally the land atop the hills, was formed on the 16th of June 1969.
It is bounded by the Nilgiris of Tamil Nadu in the east, the Arabian Sea in the west, Kozhikode and Wayanad districts in the north and Palakkad and Thrissur districts in the south.
The district has a geographical area of 3550 sq. kms, which is 9.13% of the total area of the State, and ranks 3rd in the State.
Four important rivers of Kerala flow through the district: the Chaliyar, the Kadalundippuzha, the Bharathapuzha and the Tirurpuzha.
The Chaliyar has a length of 169 km, originates from the Illambaleri hills in Tamil Nadu and flows into the sea at Beypore in Kozhikode district.
The Kadalundippuzha is formed by the confluence of the Olipuzha and the Veliyar and has a course of 130 km, reaching the sea at Kadalundi Nagaram; the Tirurpuzha is 48 km long and rises in the Athavanad hills in Tirur taluk.
Of these rivers only the Chaliyar is perennial, which is why the district is prone to drought.
The district has a total forest area of 758.8684 sq km, of which 325.3261 sq km is reserve forest and 433.5423 sq km vested forest, protected by the Nilambur North and Nilambur South divisions.
Malappuram was the military headquarters of the Zamorins of Kozhikode and was home to the Khilafath movement and the Mappila revolts.
District formed:
16 June 1969
Geographical area:
3550 sq. kms
Share of the State's area:
9.13%
Length of the Chaliyar:
169 KMs
Total forest area:
758.8684 Square km
Why it matters for exams: River sources and lengths, district formation dates and area shares are repeatedly asked in the Kerala geography section.
Kerala PSCUPSC
In plain words
Perennial river Perennial river — A river that carries water through the whole year instead of drying up in summer.
Vested forest Vested forest — Private forest land that vested in the State government under Kerala's private forests legislation.
Zamorin Zamorin — The title of the ruler of Kozhikode in medieval Kerala.
Background
Four Austrian properties carry state of conservation reports dated 2026, which is what brings the country's World Heritage record into view this week: the Historic Centre of Vienna, the Historic Centre of the City of Salzburg, the Fertoe / Neusiedlersee Cultural Landscape and the Frontiers of the Roman Empire - The Danube Limes (Western Segment).
Austria has 12 properties inscribed on the UNESCO World Heritage List, 11 of them cultural and one natural.
Austria ratified the World Heritage Convention on 18 December 1992.
The cultural properties include the Historic Centre of Vienna (2001), the Palace and Gardens of Schoenbrunn (1996), the Historic Centre of the City of Salzburg (1996), the Semmering Railway (1998) and the Wachau Cultural Landscape (2000).
The single natural property is the Ancient and Primeval Beech Forests of the Carpathians and Other Regions of Europe, a site shared across several countries.
Austria also keeps two sites on its Tentative List, the inventory of properties a State Party intends to consider for nomination.
Properties inscribed:
12
Cultural properties:
11
Natural properties:
1
Convention ratified:
18 December 1992
Sites on the Tentative List:
2
Why it matters for exams: Country-focus papers ask how many World Heritage sites a country holds and which of them is the natural one, and Austria's list is a standard example of a mostly cultural inscription record.
Kerala PSCUPSCSSC
In plain words
State Party State Party to the World Heritage Convention — A country that has ratified the World Heritage Convention and can therefore nominate sites.
Tentative List Tentative List — A country's own inventory of sites it intends to consider nominating later.
Limes Limes — The Latin word for the fortified frontier of the Roman Empire.
Background
The European Commission's country page for Austria's recovery and resilience plan values the plan at 4.187 billion euros, of which 3.961 billion euros are grants.
The plan contains 34 investment streams and 29 reforms.
56 per cent of the plan is allocated to climate objectives and 36 per cent to the digital transition.
Austria received 450 million euros in pre-financing, and its first payment request was approved for 700 million euros.
Five payment requests have been submitted in all, the fifth being the final one.
All milestones and targets had to be completed by August 2026, as the Recovery and Resilience Facility Regulation requires of every member state.
This is the framework within which the Commission cleared Austria's closing payment, and it explains why the money arrives in instalments rather than at once.
Total plan value:
4.187 billion euros
Of which grants:
3.961 billion euros
Investments and reforms:
34 investments, 29 reforms
Climate and digital shares:
56% climate, 36% digital
Pre-financing received:
450 million euros
Why it matters for exams: The size and shape of a member state's recovery plan, and the share set aside for climate and digital goals, are the figures asked about European Union finance.
Kerala PSCUPSC
In plain words
RRF Recovery and Resilience Facility — The European Union instrument that pays member states for reforms and investments against agreed milestones.
Pre-financing Pre-financing — An advance paid before any milestone is met, to start the plan off.
2 October 2026
An avalanche struck the base camp of Himlung Himal, a 7,126-metre peak in Nepal's Manang district near the border with China, early on Sunday 27 September 2026. Nepali expedition workers were pitching tents and fixing ropes for later expeditions when the snow swept through, burying the camp under more than four metres of snow. Rescuers recovered eight more bodies on Thursday 2 October 2026, taking the confirmed toll to fifteen, with one worker still missing. Tul Singh Gurung, president of the Nepal National Mountain Guide Association, said an eleven-person rescue team of experienced guides carried out the recovery and that the missing worker's chances of survival were slim, with operations likely to be concluded. The search was led by the expedition operator Mingma G Sherpa of Imagine Nepal Trek and Expedition, whose team flew from Kathmandu and was taken by helicopter to base camp from Chame. No foreign climbers had reached the site when the avalanche struck. The toll makes it one of Nepal's worst recent mountaineering disasters, after the 2014 Everest avalanche in which sixteen people died.
Peak and height:
Himlung Himal, 7,126 metres
District:
Manang, Nepal
Date of the avalanche:
27 September 2026
Confirmed dead:
15, with one worker missing
Depth of snow over the camp:
more than four metres
Why it matters for exams: Himalayan peaks, their heights and the districts they stand in are asked about, and the role of Nepali expedition workers on high peaks is a recurring theme.
Kerala PSCUPSC
In plain words
Avalanche Avalanche — A mass of snow and ice sliding rapidly down a mountain slope.
Base camp Base camp — The lowest and main camp of a climbing expedition, from which higher camps are supplied.
2 October 2026
A study in Nature, in the issue dated 1 October 2026, finds that multidecadal changes in the length of Earth's day are driven primarily by gravitational torque exerted by the planet's inner core. The length of day is not constant: fluctuations of several milliseconds occur on timescales of 10 to 70 years, and the authors analysed the record from 1964 to 2019. They report a broad oscillation of about 60 to 70 years in the rotation of the inner core. Because the inner core rotates slightly differently from the mantle, it becomes misaligned in longitude with mass anomalies in the lower mantle, and the resulting gravitational torque dominates the multidecadal fluctuation. Electromagnetic and topographic coupling at the core-mantle boundary act in the opposite direction, resisting the change rather than causing it. The finding assigns the main cause of these long-period changes to the deep interior of the planet rather than to the atmosphere or the oceans.
Dominant cause:
gravitational torque of the inner core
Size of fluctuation:
several milliseconds
Timescales analysed:
10 to 70 years
Observation window:
1964 to 2019
Inner core oscillation period:
about 60 to 70 years
Why it matters for exams: Earth's interior structure and the variability of the length of day connect geography and physics, and both are examined directly.
Kerala PSCUPSC
In plain words
LOD Length of day — The time Earth takes to complete one rotation, which varies slightly from day to day.
Inner core Earth's inner core — The solid innermost region of Earth, lying inside the liquid outer core.
Torque Torque — A turning force that changes the rotation of a body.
Core-mantle boundary Core-mantle boundary — The surface separating Earth's rocky mantle from its metallic core.
2 October 2026
A paper in Nature, in the issue dated 1 October 2026, reports that agricultural liming acts as a carbon sink in the Mississippi River Basin rather than a net source of carbon dioxide. Liming is the spreading of carbonate minerals such as limestone and dolomite on farmland to counter soil acidification. The authors estimate about 0.44 GtCO2 of carbon dioxide removal potential from the lime added to the basin since 1900, with roughly 90 per cent of that realised at the catchment scale. The Mississippi River Basin covers 41 per cent of the land area of the contiguous United States and 65 per cent of its cropland. The study argues that current accounting frameworks apply an incomplete counterfactual, attributing carbon dioxide emissions to the lime rather than to the human-caused acid inputs that drive the release. Measured against those acid inputs, liming is a net sink on decadal to century timescales while also improving crop yields and soil health. Institutions involved include the Environmental Defense Fund and Yale University.
Carbon dioxide removal potential:
about 0.44 GtCO2 from lime added since 1900
Share realised at catchment scale:
roughly 90 per cent
Share of contiguous US land area:
41 per cent
Share of US cropland:
65 per cent
Why it matters for exams: Carbon accounting, soil acidification and carbon dioxide removal are standing environment topics, and a finding that reverses a sign in the carbon ledger is readily asked about.
Kerala PSCUPSC
In plain words
Liming Agricultural liming — Spreading carbonate minerals such as limestone or dolomite on farmland to reduce soil acidity.
Carbon sink Carbon sink — Anything that absorbs more carbon than it releases over a given period.
GtCO2 Gigatonnes of carbon dioxide — A unit equal to one billion tonnes of carbon dioxide.
Counterfactual Counterfactual baseline — The comparison case of what would have happened had the action not been taken.
2 October 2026
A study in Nature, in the issue dated 1 October 2026, reports chromosome-level long-read genome assemblies from 103 bat species, of which 42 are new, representing all 21 bat families. The authors combined the genomes with 44 pre-Quaternary fossils to rebuild the bat family tree. Their analyses conclude that bats, and therefore powered flight in mammals, probably originated in Europe in the late Palaeocene, rather than in Africa or North America as earlier hypotheses had proposed. The study resolves the long-disputed position of the Madagascar sucker-footed bat family, Myzopodidae, placing it as the earliest branch within the superfamily Vespertilionoidea instead of within Noctilionoidea. It also identifies Emballonuroidea and Vespertilionoidea as sister groups and supports a reconstruction of 26 ancestral bat chromosomes. Placing the fossils on the tree indicates that laryngeal echolocation predates the diversification of crown bats. The work appears alongside a companion paper on Myotis bat genomes and longevity.
Genomes assembled:
103 bat species, 42 of them new
Bat families covered:
all 21
Fossils used:
44 pre-Quaternary fossils
Ancestral chromosomes supported:
26
Proposed place and time of origin:
Europe, late Palaeocene
Why it matters for exams: Bats are the only mammals with powered flight, and a revised origin for them is the kind of finding that enters science and environment questions.
Kerala PSCUPSC
In plain words
Echolocation Echolocation — Finding objects by sending out sound and listening to the returning echoes.
Palaeocene Palaeocene epoch — The geological epoch that began about 66 million years ago, just after the extinction of the dinosaurs.
Genome assembly Genome assembly — The reconstruction of an organism's full DNA sequence from many shorter read fragments.
2 October 2026
Chief Minister V.D. Satheesan said in Kochi on Friday, October 2, 2026, that Keralam would set up model plants for plastic waste disposal and waste-to-energy conversion within two years.
He said two or three model plants were needed for plastic waste disposal and four or five for converting regular waste into power.
He was inaugurating the Local Self-Government Department's five-year campaign, 'Nirmalam - A New Era of Clean Keralam'.
The campaign aims to make Keralam completely waste-free by March 30, 2031, and is divided into three phases with specific targets and timelines.
Satheesan said large-scale waste management projects were being launched in Kozhikode and Kochi with the support of Bharat Petroleum Corporation Limited and other agencies.
He said the Kochi Corporation had allotted another 12 acres for a new project.
He said the government would allocate the necessary funds to the Local Self-Government Department and cautioned local bodies against companies making exaggerated claims about foreign waste management technologies.
Local Self-Government Department Minister K.M. Shaji and Ernakulam Member of Parliament Hibi Eden also spoke at the function.
Campaign:
Nirmalam - A New Era of Clean Keralam
Waste-free target:
March 30, 2031
Plastic waste model plants:
two or three
Waste-to-power model plants:
four or five
Land allotted by Kochi Corporation:
12 acres
Why it matters for exams: The Nirmalam target date, the number of model plants and the departments involved are the specifics asked about state missions.
Kerala PSCUPSC
In plain words
LSGD Local Self-Government Department — The Kerala department that administers panchayats and municipalities.
Waste-to-energy Waste-to-energy — Converting non-recyclable waste into electricity or heat.
BPCL Bharat Petroleum Corporation Limited — A central public sector oil company.
2 October 2026
The Kerala government has doubled the compensation paid to farmers for crop damage caused by wildlife attacks.
Agriculture Minister T. Siddique said cocoa has been newly included in the list of crops eligible for compensation.
Under the revised scheme, ₹15 will be paid for each coconut that wild animals, including monkeys, carry away or destroy.
The decision followed discussions the Agriculture department held with the Chief Minister and the Finance Minister.
Forest Minister Shibu Baby John said the government plans to address the rising human-wildlife conflict in three ways and will pay compensation in a time-bound manner.
For mitigation, the forest areas of the State have been classified into 14 landscapes, covering 55 panchayats, where defensive measures will be carried out.
Marketing support will be promoted for crops that wild animals do not destroy.
A pilot project called 'Homestay Back Packing' will be started to link farmers living near forests to eco-tourism for additional income.
Rate for each coconut:
₹15
Crop newly included:
Cocoa
Forest landscapes:
14
Panchayats covered:
55
Why it matters for exams: The revised rate per coconut, the inclusion of cocoa and the 14 landscapes covering 55 panchayats are precise figures Kerala PSC can ask.
Kerala PSCUPSC
In plain words
Human-wildlife conflict Human-wildlife conflict — Damage to life, crops or property caused when wild animals move into areas where people live and farm.
Landscape Landscape — A unit of forest and adjoining land treated together for planning conflict mitigation.