ALICE detects the conversion of lead into gold at the LHC

• Transforming the base metal lead into the precious metal gold was a dream of medieval alchemists.
•  This long-standing quest, known as chrysopoeia, may have been motivated by the observation that dull grey, relatively abundant lead is of a similar density to gold, which has long been coveted for its beautiful colour and rarity.
•  It was only much later that it became clear that lead and gold are distinct chemical elements and that chemical methods are powerless to transmute one into the other.
• With the dawn of nuclear physics in the 20th century, it was discovered that heavy elements could transform into others, either naturally, by radioactive decay, or in the laboratory, under a bombardment of neutrons or protons.
• Though gold has been artificially produced in this way before, the ALICE collaboration has now measured the transmutation of lead into gold by a new mechanism involving near-miss collisions between lead nuclei at the LHC.
• Extremely high-energy collisions between lead nuclei at the LHC can create quark–gluon plasma, a hot and dense state of matter that is thought to have filled the universe around a millionth of a second after the Big Bang, giving rise to the matter we now know.
• However, in the far more frequent interactions where the nuclei just miss each other without “touching”, the intense electromagnetic fields surrounding them can induce photon–photon and photon–nucleus interactions that open further avenues of exploration.
• The electromagnetic field emanating from a lead nucleus is particularly strong because the nucleus contains 82 protons, each carrying one elementary charge.
• Moreover, the very high speed at which lead nuclei travel in the LHC (corresponding to 99.999993% of the speed of light) causes the electromagnetic field lines to be squashed into a thin pancake, transverse to the direction of motion, producing a short-lived pulse of photons. Often, this triggers a process called electromagnetic dissociation, whereby a photon interacting with a nucleus can excite oscillations of its internal structure, resulting in the ejection of small numbers of neutrons and protons.
• To create gold (a nucleus containing 79 protons), three protons must be removed from a lead nucleus in the LHC beams.
• “It is impressive to see that our detectors can handle head-on collisions producing thousands of particles, while also being sensitive to collisions where only a few particles are produced at a time, enabling the study of electromagnetic ‘nuclear transmutation’ processes,” says Marco Van Leeuwen, ALICE spokesperson.
• The ALICE team used the detector’s zero degree calorimeters (ZDC) to count the number of photon–nucleus interactions that resulted in the emission of zero, one, two and three protons accompanied by at least one neutron, which are associated with the production of lead, thallium, mercury and gold, respectively. While less frequent than the creation of thallium or mercury, the results show that the LHC currently produces gold at a maximum rate of about 89 000 nuclei per second from lead–lead collisions at the ALICE collision point.
•  Gold nuclei emerge from the collision with very high energy and hit the LHC beam pipe or collimators at various points downstream, where they immediately fragment into single protons, neutrons and other particles. The gold exists for just a tiny fraction of a second.
• The ALICE analysis shows that, during Run 2 of the LHC (2015–2018), about 86 billion gold nuclei were created at the four major experiments. In terms of mass, this corresponds to just 29 picograms (2.9 ×10^-11 g).
• Since the luminosity in the LHC is continually increasing thanks to regular upgrades to the machines, Run 3 has produced almost double the amount of gold that Run 2 did, but the total still amounts to trillions of times less than would be required to make a piece of jewellery. While the dream of medieval alchemists has technically come true, their hopes of riches have once again been dashed.
• “Thanks to the unique capabilities of the ALICE ZDCs, the present analysis is the first to systematically detect and analyse the signature of gold production at the LHC experimentally,” says Uliana Dmitrieva of the ALICE collaboration.
• “The results also test and improve theoretical models of electromagnetic dissociation which, beyond their intrinsic physics interest, are used to understand and predict beam losses that are a major limit on the performance of the LHC and future colliders,” adds John Jowett, also of the ALICE collaboration

Microplastics now deeply embedded in ocean structure, altering biogeochemical processes

• Plastic pollution in the ocean has extended far beyond floating surface debris — microplastics have become so deeply embedded in the ocean’s structure that they are now altering the planet’s biogeochemical cycles, scientists have warned in a new study.
• A study published highlighted that microplastics — particles between 1 and 100 micrometres in size — dominate the marine environment. While larger plastic fragments (100 to 5,000 micrometres) were typically concentrated near the ocean surface, smaller particles were discovered embedded as deep as 100 metres within ocean gyres.
• Gyres are circular water currents in ocean basin and act like huge, slow-moving whirlpools that arrest and concentrate floating debris, mainly plastic.
• Although the presence of microplastics throughout the ocean water column has been known, this study marked the first time researchers analysed their vertical distribution across depths in such detail.
• The researchers synthesised data from 1,885 ocean stations gathered between 2014 and 2024 to understand how microplastics travel through the water column. They focused on the subsurface layer, defined as approximately 50 centimetres below the surface.
• They detected more than 56 polymer types in the dataset, with buoyant polymers — representing nearly half of global plastic production — dominating subsurface microplastic presence.
• The water column, which comprises the majority of Earth’s habitable environment, plays a crucial role in biogeochemical cycling. Researchers warned that it is increasingly impacted by microplastics, which in turn may be affecting the ocean’s carbon cycle.
• The study noted that subsurface microplastics sampling is concentrated in the Atlantic and Atlantic-Arctic oceans.
• “High abundances have been consistently observed in deep waters, including over 1,100 particles per m³ at 100–270 m in a North–South Atlantic transect, 600 particles per m³ at 2,000 m in the North Pacific Subtropical Gyre, 200 particles per m³ at 2,500 m in the Arctic and 13,500 particles per m³ at 6,800 m in the Mariana Trench,” the study observed.
• Along South Korea’s coast alone, an estimated 3.13 trillion microplastic particles (ranging from 0.33 to 4.75 millimetres in size) were present in the water column. While this accounted for only a fraction of the estimated 171 trillion floating plastic particles globally, it nonetheless highlighted the scale of the problem, the paper said.
• In the Atlantic Ocean, microplastics sized between 32 and 651 micrometres were detected in the top 200 metres at an average concentration of 2,200 particles per cubic metre. The estimated total mass was between 11.6 and 21.1 million metric tonnes.
• This mass was comparable to the total input of plastics larger than 300 micrometres into the Atlantic Ocean and its sediments between 1950 and 2015, which was estimated at 17-47 million metric tonnes.
• The study, however, cautioned that the estimates came with a high degree of uncertainty due to inconsistent sampling methods, limited data resolution and simplified assumptions about ocean dynamics.
• They observed that microplastic concentrations generally declined with depth, especially in nearshore waters, where levels dropped up to 1,000-fold compared to offshore areas.
• The study also found that dense microplastics were unevenly distributed in smaller size fractions, particularly in the North Pacific Subtropical Gyre. These dense plastics — such as PET, often used in beverage bottles — likely underwent extensive weathering and degradation before reaching open ocean gyres, having taken years to travel from land-based sources.
• A separate study in the same gyre revealed that nearly half the sampled plastics with identifiable production dates originated from the 20th century, underscoring the longevity of plastic pollution and its capacity for microplastic generation over time. Fishing gear, including nets made from nylon and polyester, was identified as a major source of dense microplastic pollution. 
• The new study also pointed to atmospheric sources of pollution. “The atmosphere-ocean influx of microplastics, estimated to range from 0.013 million tonnes to 25 million tonnes annually, may also contribute, with polyester comprising a significant fraction of airborne microplastics,” the research said.
• Crucially, the researchers stated that plastic debris now represented a measurable component of the ocean’s carbon cycle. The study found that plastic pollution adds external carbon (called allochthonous carbon) to marine ecosystems. This is measured by looking at the mass of plastic particles and the amount of carbon in the chemical makeup of common plastics.
• The analysis showed that the ratio of microplastic carbon to total particulate organic carbon (POC) increased with ocean depth in subtropical gyres. Microplastic carbon made up just 0.1 per cent of total POC at 30 metres, but this rose to 5 per cent at depths of 2,000 metres.
• This proportion is expected to increase over time and the microplastics used by organisms like microbes — along with the substances they release during digestion like metabolites and organic debris — can affect natural processes like nitrification and denitrification in the environment.
• This has major implications for marine carbon dating. “A 5 per cent contribution of plastic-C could make marine POC samples appear approximately 420 years older than their true apparent age,” the paper said. 
• The researchers called for long-term studies to better understand the impact of plastics in their biological cycles

Microgravity increases core body temperature: IIST model 

• The Voyager 1 spacecraft was 25 billion km away in February, somewhere in the outer edge of the solar system. It’s the farthest a human-made spacecraft has gone from the earth. The hope is that in the distant future, a human astronaut will be able to go where Voyager 1 has been — a journey that could take several years of spaceflight.
• An important factor that determines an astronaut’s well-being on such journeys is thermoregulation: their body’s capacity to maintain a stable internal temperature. In the unique microgravity environment of space, this process faces significant challenges.
• Now, researchers at the Indian Institute of Space Science and Technology (IIST), Thiruvananthapuram, have published a study reporting that “microgravity consistently increases core body temperature, with fluid shifts playing a crucial role in thermal balance,” in the words of Shine S.R., a professor of aerospace engineering at IIST and an author of the study.
• Human bodies respond differently to temperature changes based on age, fitness level, and body fat, among other parameters. In environments with near-zero gravity like space, the human body changes significantly, affecting bones, muscles, the heart, the immune system, metabolism, even individual cells.
• Some of the resulting complications can be severe, so space agencies and astronauts continuously monitor the spacefarer’s body temperature.
• Scientists using a computer model to evaluate the body’s ability to regulate temperature in specific conditions must also account for “physiological changes observed in space, including blood shifts, metabolic variations, muscle atrophy, and environmental influences”.
• Shine said his team has developed a 3D computational model of human thermoregulation that “incorporates these changes to simulate the effects of microgravity on thermoregulation, including blood redistribution, reduced blood volume, changes in metabolism, and alterations in bone and muscle mass”.
• According to Chithramol M.K., PhD student at IIST and first author of the study, the team’s studies were limited by sufficient as well as accessible data on metabolic changes.
• The model uses mathematical equations to track how heat moves through the body in three dimensions, and accounts for mechanisms like sweating and shivering, the impact of clothing, heat generated by vital organs, and other factors that have a say on how a body regulates its temperature.
• Each factor is modeled separately and then combined to understand the overall impact of microgravity on thermoregulation.
•  “Our findings reveal that the redistribution of blood from the lower limbs to the upper body in microgravity environments significantly impacts the body’s temperature distribution,” Shine and Chithramol said.
• Specifically, the researchers reported that while the feet and hands become cooler as the body spends more time in microgravity, the head, abdomen, and the core get warmer.
• The model also indicated that when astronauts exercise in space, their body temperature rises faster than it does on the earth.
• Over 2.5 months in microgravity, considering 30% lower sweating and 36% higher metabolism, the core body temperature may increase to around 37.8º C from 36.3º C before flight. If one were exercising in the same conditions, the temperature would be closer to 40º C.
• The researchers were able to confirm their model was able to predict real outcomes by using it to simulate astronauts’ body temperature onboard the USSR’s and Russia’s erstwhile Mir space station and onboard the International Space Station, then compared its output to official reports. They matched.
• Most current models that predict how bodies regulate temperature mostly use data from non-Indian populations. Different body types and physiological processes modulate thermoregulation differently; a model specific to one population group may fail to predict specific outcomes when applied to another group.
• As thermoregulation models indicate how a person responds to temperature changes, they are also used in many everyday situations. For example, clothiers use such models to fine-tune how their products keep people warm or cool. Architects use such models to design buildings to lower heat stress of their occupants. In medicine, especially during heart surgeries, thermoregulation models predict how a patient’s body temperature changes, helping both doctors and patients avoid complications.
• According to the IIST team, these models calculate the universal thermal climate index — a number that indicates how hot or cold it feels outside by considering factors like wind, humidity, and sunlight.
•  “These models are valuable tools for enhancing safety, comfort, and performance in diverse real-world scenarios” in addition to astronaut health and safety in microgravity environments. “Take our model, for example: while [it] was developed with the human space program in mind, we have also realised its potential in various everyday situations on earth.

Scientists have found a cricket evolving rapidly to beat a new threat

• Climate change is reshaping the world — and perhaps nowhere more so than in the wild. As ecosystems change, species are forced to move to new locations in search of the resources they need to live.
• Unlike some human-made borders that are visible as fences and walls, the wild at large has numerous borders invisible to humans crisscrossing each other. When climate change causes an animal to migrate, it may cross one of these borders — and there new challenges await.
• Some newcomers quietly adapt to their new environs. Others go rogue and become invasive, throwing the lives of native species in chaos. These invasions are becoming more common, which means more and more native species are being forced to make a choice: evolve to survive or perish.

A love song vanishes

• On the Hawaiian islands, Pacific field crickets (Teleogryllus oceanicus) evolved — and how. To avoid being hunted by an invasive parasitoid fly called Ormia ochracea, they have started remixing the songs they’ve been using to find mates..
• About 30 years ago, as O. ochracea flies flew into Hawaii from tropical America, the sound of Pacific field crickets’ love songs vanished from the islands. Using their acute sense of hearing, the flies were able to zero in on male crickets as they sang and laid their eggs inside the crickets’ bodies.
• When the larvae hatched, they fed on the nutrients around them and eventually burrowed out, killing the crickets.
• “About 20 years ago, we discovered a population on Kauai [in Hawaii] that had gone completely silent because a mutation on their wing erased the sound-producing structures in these crickets,” University of Denver professor Robin Tinghitella said.
• “Males still rubbed their wings together but no sound came out. It was a pretty wild discovery. The mutation swept through the island because it protected crickets from flies.”
• Recently, however, Tinghitella’s group discovered populations of Pacific field crickets that still sang — but the music was somewhat different: it contained some additional subdued purrs and rattles.
•  It differed in both frequency and amplitude from the original music. The researchers found that it was still loud enough to attract females but quiet enough to evade O. ochracea flies.
• To Tinghitella, the crickets’ new adaptation signalled a “rapid pace of evolutionary change”.
• To test if the flies were evolving in sync with their prey, the researchers compared the sensitivity of Hawaiian flies to certain sounds and frequencies with that of lab-maintained native flies from Florida.
• The ancestral Floridian flies were most sensitive to sounds around 4-6 kHz, which is also the frequency most field crickets call at. On the other hand, the researchers found, the O. ochracea flies had broadened their hearing range, tuning into sounds from 6 to 20 kHz.
• Next, they placed a live fly on a spherical treadmill with speakers on either side. When they played synthetic pre-recorded cricket songs, the Hawaiian flies were more responsive to the purrs and rattles of Pacific field crickets than their ancestral counterparts.
• Despite the crickets’ efforts to stay under the radar, the flies could still find them.
• “What we are seeing isn’t a classic incremental step-by-step co-evolution, where the cricket changes a little bit in one direction and then the fly carefully tracks that, and so on,” said Tinghitella. “Instead, the flies have become more responsive to a broad range of sounds that might allow them to track a variety of changes in cricket song.”
• When the male crickets make new sounds, they aren’t changing the way they interact with flies alone. Female crickets have also become less picky in this time about male songs. “If the females had still preferred only the traditional song, males with the mutations [that cause purrs and rattles] would not have succeeded. They would have gone locally extinct,” Tinghitella said.

A new challenge

• How much and how quickly a species can evolve depends on its resilience, generation time, the plasticity of its traits, and ecological pressure. For example, organisms with short generation times, like insects, reproduce rapidly so they have more chances to evolve, potentially allowing them to respond faster to new threats.
• The populations of insects are falling in many parts of the world. Their extinction rates are estimated to be eight-times higher than those of birds, mammals or reptiles.
• Their vulnerability means even if conditions become more unfavourable than usual for a short period — e.g. a year with bad weather — populations are liable to collapse than more long-lived organisms that can better face a fluctuating threat.
• As global warming, extreme weather, and biological invasions intensify, predicting how species with varying ecological needs will respond to compounding pressures is becoming increasingly challenging. Many researchers are looking at the genomic architecture of wild insect species to predict their ability to adapt.
• According to Tinghitella, rapid evolution could explain why some invaders do so well or why some species manage to cope. To predict how these interactions are going to play out in the long-term, understanding how evolution happens in these situations is key

Ecology is the world’s permanent economy

• The phrase, “Ecology is the permanent economy”, made popular by environmentalist Sunderlal Bahuguna, is much more than a slogan. It is a profound reminder of the foundational truth that human prosperity is inextricably linked to ecological health. It is true that economic development without exploiting natural resources and economic stability without conserving them are impossible.
• As we face serious challenges such as climate change and the rapid loss of biodiversity, we must ask ourselves whether we have truly understood and embraced this idea.

Striking the right balance

• Understanding nature’s complexity is at the heart of science. In this pursuit, humans have made tremendous efforts through observation, experimentation, and modelling, as this understanding is crucial for addressing environmental challenges such as climate change and for informing sustainable practices.
•  While these scientific discussions are valuable, there is an even more urgent and fundamental truth we need to focus on: ecology is the real economy — our survival, security and progress depend on it. In simple terms, this might be the clearest way to define sustainability — finding the right balance between protecting the environment and supporting economic development.
• Without this balance, neither the environment nor the economy can thrive in the long run.
• Despite being part of the animal kingdom, human evolution, through the course of civilisation, has led to a growing disconnection from nature.
•  This disconnection with nature has been identified as a reason for the ongoing biodiversity loss (the recent Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services or IPBES Transformative Change report).
• In the early stages of human history, a nomadic lifestyle compelled individuals to rely on and exploit natural resources solely for their basic, day-to-day survival needs. Over time, this individual-centric resource use evolved into collective consumption aimed at meeting the needs of growing communities.
•  As human societies expanded and organised themselves into nations, this demand scaled further to cater to the needs of entire countries.
• Eventually, this progression gave rise to global competition, where nations began to exploit nature not only to satisfy present demands but also to secure resources for future development.
•  Unlike humans, no other species in the animal kingdom exhibits this pattern of large-scale, anticipatory exploitation of natural resources. Other animals live in harmony with their environments, taking only what they need for immediate survival, without disturbing the long-term balance of the ecosystems they inhabit.

New complications

• The ever-intensifying cycle of human consumption and global competition has placed an unprecedented strain on the planet’s ecosystems and significantly accelerated the pace of climate change — a natural phenomenon now dangerously amplified by human activities. In response to these growing environmental challenges, nature-based solutions have been widely advocated in global conservation efforts.
• These approaches aim to leverage the inherent resilience of ecosystems to mitigate climate impacts, restore biodiversity, and support sustainable development. However, a paradox emerges: we continue to exploit nature to satisfy our needs and greed, while simultaneously relying on the same natural systems to act as a buffer against the consequences of such exploitation.
• This dual dependence risks creating deeper ecological imbalances and may further complicate the ability to address the climate crisis effectively.
• In this context, rather than merely attempting to understand the intricate complexity of ecological systems from a scientific standpoint, it is far more critical to recognise a fundamental truth — that ecology is the permanent economy.
• Acknowledging this principle shifts our perspective from short-term exploitation to long-term stewardship, positioning ecological health not as a constraint, but as the very foundation of human survival, economic stability, and climate resilience.
• This realisation is not just timely — it is essential to confronting the ongoing environmental crisis and shaping a sustainable future.
• It is only through this reframing that humanity can move from reactive conservation to proactive planetary sustainability. The climate crisis is not just a scientific challenge. It is a moral and existential reckoning with the ecological foundations of our existence.

The need to reconnect with nature

• Climate change and change in distribution patterns of biological diversity are not new for planet earth. However, the rate at which it is now occurring is detrimental to the planet’s biological diversity, including people, due to past unsustainable developmental activities by humans. Therefore, the change we need must come from within.
• Since all developmental activities across the globe are aimed at fulfilling human needs, adopting a sustainable lifestyle is every individual’s responsibility in order to ensure the success of global sustainability initiatives. To achieve this, we must realise that humans are an integral part of nature.
• Though technological advancements have distanced modern lifestyles from nature, one unique natural trait that humans possess is the power to reconnect with nature using emotion (which still lives within us).
• Thus, future conservation efforts should be designed to strengthen our emotional bond with nature. To ignite this, a realisation that “ecology is the permanent economy”, is more imperative than merely understanding the ecological complexity that exists in nature

Magnetic flip-flop

• In 2022, a group of scientists unveiled a haunting soundtrack at Solbjerg Square in Copenhagen. They had converted Earth’s magnetic signals from 32 locations into sound to highlight the planet’s magnetic field, the invisible shield against harmful cosmic radiation, and its fluctuations over the past 100,000 years.
• Two years later came another soundtrack, but this was no ordinary hum. It captured Laschamps, an extreme geomagnetic excursion that occurred 41,000 years ago, during which the Earth’s magnetic field weakened to just 5 per cent of its current strength.
•  The excursion saw the magnetic north and south poles briefly switch places. The soundtrack, available on the European Space Agency’s website, has an eerie, alien-like quality.
•  The project is based on research by Sanja Panovska of the GFZ German Research Centre for Geosciences in Potsdam, and her colleagues. Now, the team is working on another composition, recreating the Brunhes-Matuyama reversal, a far more extreme event that took place 780,000 years ago.
• “If the Earth retains the change in polarity for more than 100,000 years, scientists label them as reversals. Otherwise, they are excursions,” says Mamilla Venkateshwaralu, senior principal scientist at the National Geophysical Research Institute, Hyderabad, under the Council of Scientific and Industrial Research
• Among its many roles, Earth also functions as a giant magnet, with magnetic field lines stretching from the north to the south magnetic pole.
• It originates 2,900 km below our feet in the liquid outer core, sandwiched between the mantle and the solid inner core, and is powered by electric currents generated by the movement of molten iron. Extending outward, it forms a protective bubble.
• Much about the magnetic field, though, remains a mystery, including what drives reversals and excursions. One known fact is that it fluctuates over time due to the moving fluid in the outer core, which is powered by heat release from the inner core and the rotation of the planet. “If the flow is clockwise, we have normal polarity.
•  If it moves 180° to anticlockwise direction, we get a reversal in polarity,” says Venkateshwarlu. Over the past 200 years, its strength has weakened by 10 per cent. If this decline continues at the current rate, models suggest the magnetic field could drop to zero in about 1,500-1,600 years, raising questions about whether we are heading towards another reversal or excursion.
• Data from the US National Aeronautics and Space Administration (NASA) show that over the last 83 million years, Earth’s magnetic poles have reversed 183 times.
• Excursions are far more frequent, occurring 10 times as often. Since Brunhes-Matuyama, the most recent reversal, the planet has experienced three significant excursions: the Norwegian-Greenland Sea event (64,500 years ago), Laschamps and Mono Lake (34,500 years ago).
• “It is difficult to predict reversals or excursions because they occur without any periodicity,” says William Brown, a geophysicist in the geomagnetism team of the British Geological Survey.
• The impact of these events also remains inconclusive. A 2021 study published in Science concluded that Laschamps caused substantial changes in atmospheric ozone concentration, impacting the climate over the mid to high latitudes in both hemispheres. The study noted that climatic shifts and extinction phases overlapped with the event, suggesting a link.
•  But Panovska’s yet-to-be-published study on Laschamps’ impact on Neanderthals produced contrasting results. “We found no evidence suggesting that the event affected life on Earth.
•  The reason is that we have an atmosphere, which offers protection against cosmic rays,” she says. A 2019 study in Science Advances estimates the Brunhes-Matuyama reversal took at least 22,000 years to complete, suggesting that society would have generations to adapt to a future magnetic instability.
• Another mystery is the drifting north magnetic pole. First recorded in 1831 in the Canadian Arctic, it has since moved over 1,100 km towards Siberia, accelerating from 16 km per year in the 1990s to 35 km per year today. Meanwhile, the magnetic south pole has remained relatively stable, shifting just 5 km per year.
• “The differing behaviour of the north and south poles reflects processes in the outer core. It is likely due to turbulence in the flow, but we still do not fully understand why it speeds or slows down,”

New insights

• Despite many unknowns, scientists are making strides in understanding the Earth’s magnetic behaviour. “As computers become more advanced, we can better represent how the magnetic field is generated and the dynamics driving these changes,” says Brown.
• Researchers rely on geomagnetic observatories and satellites to study the magnetic field. Together, these sources offer a comprehensive picture of how the field is evolving over time.
• But geomagnetic observatories have only been operational for about a century and satellite data have been available for just a few decades. To understand the magnetic field over longer timescales, scientists analyse ship logs dating back to 1590, which recorded compass directions.
• Yet, ship logs alone do not provide a complete geological history. To fill this gap, scientists turn to geological and archaeological evidence, collecting samples from volcanic regions, lakes, oceans and archaeological sites.
•  Lava-formed rocks, ocean and lake sediments, and ancient pottery all preserve signatures of the geomagnetic field at the time of their formation.
• “When the field is stronger, more grains align in the sediment, leading to stronger magnetisation,” says Bruce Buffett, professor at the University of California, Berkeley. Using geological samples, Venkateshwaralu and his team recently found traces of excursion events in Uttarakhand, including the Bagwalipokar excursion events 15,500-14,700 years ago and 8,000-2,850 years ago.
• In a 2023 study ,  examined cosmogenic isotopes, such as beryllium-10 and carbon-14, found in ice cores and sediments. Their analysis showed that during the Laschamps excursion, global beryllium-10 production more than dou-bled.
•  These isotopes form from the reaction of cosmic rays with oxygen and nitrogen atoms in the atmosphere, which then get deposited on land, ice and sea during precipitation.
• The idea is that more cosmic rays get deflected when the magnetic field is strong, and fewer cosmic isotopes form as a result. But when the field is strong, less cosmogenic isotopes are produced.
• Scientists also speculate that geomagnetic reversals and excursions may be linked to the South Atlantic Anomaly (SAA), a region spanning South America and South Africa where the Earth’s magnetic field is weakest. SAA allows cosmic rays and charged particles to penetrate into the atmosphere, exposing spacecraft in low Earth orbit to harmful radiation.
•  The field strength has recovered in the past. So we think the current magnetic field is probably not going to reverse soon,”.
• While scientists cannot yet predict geomagnetic reversals or excursions far into the future, they can forecast the magnetic field’s behaviour up to five years ahead.
• In December 2024, the US National Geospatial-Intelligence Agency and the UK’s Defence Geographic Centre released an updated World Magnetic Model, used by military and civilian navigation systems. “To make predictions, we analyse recent measurements and extrapolate trends forward,”
• Scientists are optimistic that future advancements in computational resources will enable higher-resolution models, bringing us closer to understanding and forecasting the planet’s magnetic behaviour.

FGD compliance under lens: SC pushes for action on non-compliant power plants over SO₂ norms

• In a major move to address industrial air pollution, the Supreme Court of India held a crucial hearing on April 29, 2025, to review the compliance of thermal power plants (TPP) within a 300-kilometre radius of Delhi with sulphur dioxide (SO₂) emission norms.
• The hearing took place under the long-standing environmental litigation case MC Mehta vs Union of India & Others filed in 1985. The bench, comprising Justice Abhay S Oka and Justice Ujjal Bhuyan, reviewed the compliance status of 11 thermal power stations and examined the central government’s progress in issuing formal notices to non-compliant plants. 

Two key issues before the court

• The court focused on two major questions, the first being reclassification of TPPs: Whether the existing classification of TPPs within 300 km of Delhi could be amended, particularly to reclassify some Category C plants as Category A, imposing stricter emission deadlines.
• This would mean amending Schedule I of the Environment (Protection) Rules, 1986, which currently defines emission norms and timelines for different categories of power plants.  
• The second was the timeline for compliance with SO₂ standards. Given repeated extensions and rising public health concerns, the court scrutinised delays in enforcing pollution control norms. Over the years, the government granted multiple extensions, delaying the implementation of critical technologies like flue gas desulphurisation (FGD).  
• In a previous hearing on April 2, 2025, the court noted that while National Capital Power Station Dadri in Uttar Pradesh and Mahatma Gandhi Super Thermal Power Project in Jhajjar, Haryana were fully compliant, others — such as Indira Gandhi Super Thermal Power Project (under NTPC Ltd and Haryana Power Generation Company Ltd) and Harduaganj Thermal Power Station in Uttar Pradesh (owned by UP Rajya Vidyut Utpadan Nigam Ltd) — showed partial compliance. 
• In the case of Rajpura TPP in Punjab (operated by Nabha Power Ltd (NPL), under Larsen & Toubro), the court found that the FGD system had been installed but was not operational.
• The Supreme Court directed the central government to submit the official addresses of nine non-compliant or partially compliant TPPs with SO₂ emission norms to issue formal legal notices.
• Each notice would include a copy of the court’s April 2, 2025 order and the plants will be informed of their obligation to respond or appear in court.  However, during the April 29 hearing, it emerged that the government had not yet submitted the required addresses.  
• Despite the overall delay, there was a positive step; advocate EC Agrawala, representing NPL for the Rajpura TPP in Punjab), independently submitted the company’s address to the court on April 17. The Supreme Court Registry issued a formal notice via speed post on April 22, and NPL e-filed a reply on 28 April.  

What did NPL tell the SC?

• NPL, which has an installed capacity of 2 units of 700 megawatts capacity each in Rajpura, told the Supreme Court that it could not start using its FGD system because it was facing problems proocuring limestone, a key material needed to run the system.
• Although the FGD system has been set up, it cannot be operated in the absence of adequate quantity and quality of limestone. The company also claimed Punjab State Power Corporation Ltd (PSPCL) was not participating in the procurement to buy the limestone needed to run the system.
• NPL had signed a Power Purchase Agreement with PSPCL in 2010, under the regulatory oversight of the Punjab State Electricity Regulatory Commission (PSERC). At that time, the installation of FGD systems was not mandatory for thermal power plants and hence, was not included in the original bid parameters.
• After environmental norms were updated to require FGD technology, NPL sought cost recovery under a ‘Change in Law’ provision, which was denied by PSERC. Although the Appellate Tribunal for Electricity (APTEL) ruled in favour of the company, PSPCL challenged the order in the Supreme Court. The matter is now sub-judice and the final judgement is awaited.
• The installed FGD system has not been put into use because of the ongoing dispute over electricity tariffs between the power company and the distribution company (discom), NPL told the SC.
• While NPL highlighted its case, several other plants are also not meeting SO₂ emission standards.
•  To ensure that FGD systems are properly implemented and operated, it is important to understand the deeper issues and lack of coordination among key stakeholders — State Electricity Regulatory Commissions, distribution companies (discoms), and power generators.

Centre seeks more time

• The Union of India’s counsel requested the SC to grant a two-month extension to assess whether TPPs’ current SO₂ compliance deadline (latest by December 31, 2029 for category C plants at present) could be amended.
• The government argued that altering timelines could trigger tariff revisions, as power producers may claim ‘Change in Law’ cost recovery.  
• Changing the deadline for compliance could have financial consequences, the counsel explained. If power plants are required to install FGD or other pollution control systems earlier than planned, it would be treated as a “change in law” under electricity regulatory frameworks. This would allow power producers to legally ask for higher tariffs to recover the extra costs. Hence, the authorities needed time to evaluate this aspect carefully.
• Acknowledging the need for regulatory and financial review, the court granted the extension, allowing the government to submit a detailed assessment

India grapples with chronic PM10 pollution as all major metros exceed safety limits: Analysis

• A new four-year air quality study has revealed alarming levels of particulate pollution across India''s major urban centres.
• The analysis by Respirer Living Sciences — a Delhi-based climate-tech startup — found that all 11 metropolitan cities monitored consistently breached the National Ambient Air Quality Standards for PM10 between 2021 and 2024, with pollution levels remaining stubbornly high despite various policy interventions.
• The most severe conditions were observed in northern India, where cities like Delhi, Patna, Lucknow and Chandigarh recorded particularly dangerous air quality.
• Delhi''s Anand Vihar monitoring station measured PM10 concentrations of 313.8 micrograms per cubic metre in 2024, while Patna''s Samanpura area saw levels reach 237.7 micrograms per cubic metre — all far exceeding the national safety standard of 60 micrograms per cubic metre.
• Even cities traditionally considered to have better air quality failed to meet standards.
• While some southern and coastal cities like Bengaluru, Chennai and Hyderabad showed modest improvements at certain monitoring sites, none managed to achieve consistent compliance with safety norms over the four-year period.
• The report identifies multiple contributing factors including vehicle emissions, industrial operations, construction activity, waste burning and seasonal agricultural burning.
• It calls for stronger enforcement of existing regulations, expanded air quality monitoring networks and tailored solutions for different cities based on their specific pollution profiles.
• Experts warn that addressing India''s air quality crisis requires moving beyond temporary measures.
• The findings highlight the persistent challenge of particulate pollution in Indian cities, with millions of residents continuing to face prolonged exposure to unhealthy air despite various clean air initiatives launched in recent years

UN chief calls for major reforms to cut costs and improve efficiency

• Mr. Guterres outlined wide-ranging effort to revamp how the UN system operates – cutting costs, streamlining operations, and modernizing its approach to peace and security, development and human rights.

Three main objectives

• Launched in March, the UN80 Initiative centres on three priorities: enhancing operational efficiency, assessing how mandates – or key tasks – from Member States are implemented, and exploring structural reforms across the UN system.
• The conclusions will be reflected in revised estimates for the 2026 budget in September this year, with additional changes that require more detailed analysis presented in the proposal for the 2027 budget.

‘Meaningful’ budget reductions

• Mr. Guterres said the changes are expected to yield “meaningful reductions” in the overall budget. For example, the departments for political and peacekeeping affairs could see a 20 per cent reduction in staff by eliminating duplication.
• This level of reduction, he said, could serve as a benchmark across the UN system – while also considering unique factors for each department.
• Additional examples include consolidating all counter-terrorism work within the main Office of Counter-Terrorism (UNOCT), ending building leases and relocating posts away from expensive “duty stations” where cost of living is high.
• “There might be immediate, one-off costs involved in relocating staff and providing potential termination packages,” he said, “but by moving posts from high-cost locations, we can reduce our commercial footprint in those cities and reduce our post and non-post costs.”

Efficiencies and upgrades

• The first workstream focuses on efficiencies and improvements, developing a new model that improves consolidation, looks at centralising services, relocating to cheaper locations, and expanding the use of automation and digital platforms.
• Mr. Guterres said departments the UN’s headquarters in New York and Geneva have been asked to review whether some teams can be relocated to lower-cost duty stations, reduced or abolished.

Reviewing mandates

• The second workstream involves a review of how existing mandates are being carried out – not the mandates themselves, which are the purview of Member States only.
• A preliminary review identified more than 3,600 unique mandates for the Secretariat alone. A full and more detailed analysis is now underway.
• Mr. Guterres emphasised that the sheer number of mandates – and the bureaucracy needed to implement them – places a particular burden on smaller Member States with limited resources.
• “Based on this work, Member States may wish to consider the opportunity to conduct themselves a review of the mandates,” he added.
• Structural change
• The third workstream – focused on structural reform – is already underway, Mr. Guterres said.
• Nearly 50 initial submissions have already been received from senior UN officials, reflecting what Mr. Guterres described as “a high level of ambition and creativity.”
• Key work areas have been identified for review. These include peace and security, development, human rights, humanitarian, training and research and specialised agencies