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The Hindu
02-08-2025
- Science
- The Hindu
Ground realities: climate and crop choices straining Telangana's water reserves
Scientists at the CSIR–National Geophysical Research Institute (NGRI) have stressed the urgent need for comprehensive groundwater extraction policies and a deeper understanding of water storage in Telangana. These measures, they say, are essential to ensure water security and protect the livelihoods of nearly half the working population, who are actively engaged in agriculture and rely heavily on groundwater. In a recent study, scientists Abhilash Kumar Paswan, N. Srinivasa Rao, L. Raghu and V.M. Tiwari highlight how geological formations, agricultural water use and erratic rainfall patterns interact to create a complex and uneven groundwater recharge system. Telangana grows two paddy crops annually, using up around 15 billion cubic metres of groundwater. The Rabi (summer) crop, in particular, is highly dependent on aquifer availability. Although the State receives 70-150 cm of rainfall annually, only about 15% contributes to groundwater recharge, often with a delay of up to two months due to a poorly developed soil profile, limited aquifer storage capacity and fractured bedrock systems, they note. Paswan cautionsabout a rise in temperature ranging from 0.3 to 2.94°C and a potential 15%–50% increase in annual rainfall from south to north in the 21st century under various climate scenarios. However, the intensity and frequency of rainfall are expected to remain highly uncertain in Telangana. Depletion of groundwater is impacted by rainfall, climate variability and irrigation activities, particularly in the context of paddy cultivation, widely practised in the hard rock region, covering approximately 85% of the total geographical area. Over-extraction of groundwater could lead to declining water levels. Over the past 34 years, groundwater-irrigated areas have nearly tripled, and the average annual groundwater level has been recorded at 9.32 metres, showing distinct fluctuation patterns. About 60% of the total arable area is concentrated in hard rock terrain, while forests occupy approximately 24%, mostly in sedimentary terrain in the north. Telangana, classified into three agroclimatic zones based on climatic parameters, is highly dependent on the monsoon system for water availability. Using data from the 'Gravity Recovery and Climate Experiment' satellite, the scientists analysed Terrestrial Water Storage (TWS) between 2002 and 2020, showing that water is available during the Kharif season, coinciding with the southwest monsoon. During the Rabi season, groundwater extraction increases due to low surface water availability. In regions with limited Groundwater Storage (GWS) capacity — particularly hard rock areas — the cultivation of two water-intensive paddy crops per year can lead to a declining water table, they said. The study found that if the preceding year's rainfall is low, GWS recharge remains minimal, and the anomaly may persist even with substantial rainfall in the following year. However, there are also times when water availability is high despite low rainfall, indicating the presence of other water sources or reduced water loss likely linked to human activities. Groundwater also exhibits a similar pattern, but with a lag, indicating its dependence on the overall water balance over time. Groundwater recharge is influenced by infiltration, soil characteristics and human abstraction. The lowest values occur in May-June, and the highest in October-November. Although abundant rainfall can swiftly replenish aquifers, the increasing frequency of drought over the past few decades poses a significant challenge to their sustainability, they said. The study also revealed a strong correlation between rainfall and the top 100 cm of soil moisture, emphasising the importance of including soil moisture columns in TWS studies, especially in hard rock settings. Understanding storage dynamics is crucial to ensuring water security and groundwater sustainability in Telangana. The Academy of Scientific and Innovative Research, Ghaziabad, the Indian Institute of Technology Bombay, and the CSIR–Northeast Institute of Science and Technology, Jorhat, were also involved in the study.
The Hill
28-07-2025
- Science
- The Hill
Freshwater is disappearing from the Earth at alarming rates: Study
The planet has endured massive freshwater losses over the past two decades due to the combined effects of climate change, overconsumption and drought, a new study has found. Arid land areas are expanding at a rate roughly twice the size of California each year, according to the study, published in Science Advances. Dry spots are now drying up faster than wet areas are getting wetter — reversing historic hydrological patterns, per the research. This continental-scale phenomenon of 'mega-drying,' the study authors warned, could have severe consequences on water security, agriculture, sea level rise and global stability. Describing their results as 'staggering,' the researchers determined that 75 percent of the world's population lives in 101 countries that have been losing freshwater for the past 22 years 'These findings send perhaps the most alarming message yet about the impact of climate change on our water resources,' principal investigator Jay Famiglietti, a professor at Arizona State University's School of Sustainability, said in a statement. 'Continents are drying, freshwater availability is shrinking, and sea level rise is accelerating,' Famiglietti added. To evaluate changes in terrestrial water storage, the researchers combed through more than two decades of satellite observations — from April 2002 through April 2024 — from NASA's Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On missions. They defined terrestrial water storage as all of Earth's surface and vegetation water, soil moisture, ice, snow and groundwater stored on land. Ultimately, the researchers identified robust changes in these water storage levels since previous global studies. These declines, they found, have been driven by high-latitude water losses in Russia and Canada, extreme in Central America and Europe and groundwater depletion — responsible for 68 percent of the losses alone. The researchers also identified a 'tipping point' in 2014-2015, years that meteorologists generally characterize as 'mega El-Niño.' In North America, El-Niño years typically involve dryness and warmth in the northern U.S. and Canada, with increased flooding in the South. Near the tipping point, climate extremes began accelerating, leading to a surge in groundwater use and continental drying-up that surpassed the rates of glacier and ice sheet melting, per the study. Evaluating their 22 years of data, the scientists also determined that certain water storage loss 'hotspots' previously assumed to be isolated were actually interconnected. These places, they concluded, make up four continental-scale, mega-drying regions. The first region spans the U.S. Southwest, Mexico and Central America and includes many major food-producing regions. The second, meanwhile, includes Alaska and Northern Canada, which are stricken by snow and permafrost melt, as well as drying in agricultural zones. Northern Russia, per the study, is the third region and is also undergoing considerable snow and permafrost melting in high latitude zones. The fourth area, the Middle East-North Africa region and Pan-Eurasia, houses multiple major desert cities, food producing hubs, shrinking seas and urban cities, the researchers noted. 'It is striking how much non-renewable water we are losing,' lead author Hrishikesh Chandanpurkar, a research scientist at Arizona State, said in a statement. 'Glaciers and deep groundwater are sort of ancient trust funds,' he added. 'Instead of using them only in times of need such as a prolonged drought, we are taking them for granted.' Chandanpurkar also lamented the fact that humans are failing to replenish groundwater reservoirs during wet years and are thereby nearing 'an imminent freshwater bankruptcy.' Describing their findings as 'a planetary wake-up call,' the authors stressed a need for ongoing research that can help inform policymakers about these dire water challenges. The researchers also advocated for community-level opportunities to make meaningful change, particularly when it comes to excessive pumping of groundwater. The consequences of overusing the remaining groundwater, Famiglietti warned, could threaten 'food and water security for billions of people around the world.' 'This is an 'all-hands-on-deck' moment — we need immediate action on global water security,' he said.
DW
29-06-2025
- Science
- DW
Fact check: Climate deniers misinterpret Antarctic ice study – DW – 06/26/2025
Satellite data shows that Antarctic ice sheets have grown in size, prompting claims that climate change is in reverse or even a hoax. But it's not that simple. A recent study has found that the Antarctic ice sheet mass has slightly increased in size in recent years, prompting a wave of claims on social media (such as here and here) that global warming may be reversing. Published in March 2025 by researchers at Tongji University in Shanghai, China, the study reported that the Antarctic ice sheet gained approximately 108 billion tons of ice annually between 2021 and 2023. This data focused on four glacier basins in the Wilkes Land-Queen Mary Land region of the eastern Antarctic ice sheet, has been misinterpreted by some climate skeptics as evidence that climate change is a "hoax." DW Fact Check looked at the numbers. Claim: Posts on platforms like X (formerly Twitter) have gone viral, with one stating, "Moral of the story: Never believe a climate alarmist," garnering over 270,000 views. Another viewed more than 55,000 times, claimed,"Scientists have had to pause the Climate Change Hoax Scam." DW Fact Check: Misleading One post even featured a GIF that the user believed showed new land emerging off the coast of Dubai due to falling sea levels — apparently unaware of the artificial Palm Islands constructed there between 2001 and 2007. The findings in the Chinese study are based on publicly available data from NASA's Gravity Recovery and Climate Experiment satellites, which have been measuring the Earth's gravitational field since 2002 and have documented changes in the planet's ice and water masses. The data may be correct, but its interpretation by conspiratorial social media users is not — a situation not helped by the researchers' decision to insert an increasing average trend curve next to the preceding decreasing curve depicting ice mass. "This is perfect fodder for people who are intentionally looking to spread disinformation," said Johannes Feldmann, a physicist at the Potsdam Institute for Climate Impact Research near Berlin. Feldmann emphasized that climate science relies on long-term data — typically over 20 to 30 years — to identify meaningful trends. "Two, three or even five years are far too little to identify a long-term trend," he explained. Cherry-picking short-term data is a common tactic among climate change deniers. "There are always phases where the increase [in temperature] levels off a bit, which people suddenly take to mean: global warming has stopped, the trend is reversing," Feldmann added. "But it's never turned out to be true." To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video The Antarctic ice sheet, like many natural systems, is subject to fluctuations. A 2023 study from the University of Leeds in the United Kingdom highlighted how meteorological events, such as unusually heavy or light snowfall, can temporarily affect ice mass and sea levels. Therefore, fluctuations such as those observed between 2021 and 2023 are to be expected. "We're dealing with a natural system that is subject to fluctuations — and this is nothing unusual," said Angelika Humbert, a glaciologist at the Alfred Wegener Institute in Bremerhaven, northern Germany. "We sometimes have years with a lot of snow and sometimes years with no snow at all, and it's the same for ice sheets." The Tongji University researchers themselves acknowledged this in a separate 2023 study, linking increased ice mass in eastern Antarctica to unusually high snowfall. "Given the warmer atmosphere, we know that these snowfall events could increase in the coming years," said Feldmann. "On the one hand, this means more snow could fall more often [on the ice sheets] but also that more could melt — because it's getting warmer. "This is all well-researched and will continue to be researched," he added. "There was a brief increase [in Antarctic ice mass], but it didn't come anywhere close to replacing the losses of recent decades. The long-term development we are observing is a large-scale loss of the Antarctic ice sheet."
Time of India
11-06-2025
- Science
- Time of India
7 essential facts about NASA satellites that students can't miss
The National Aeronautics and Space Administration ( NASA )'s flotilla of satellites orbiting Earth and deep space is far more sophisticated than most people realise. These technological spectacles aren't just scanning skies and taking mind-boggling pictures; they're rewriting science and human understanding of space. These satellites are protecting our planet and unlocking cosmic mysteries far beyond. Here are 7 extraordinary capabilities that showcase the incredible ingenuity of modern space technology that students can't afford to miss. Laser highways in space replace traditional radio communication Whilst most people assume satellites communicate through radio waves, NASA's most advanced spacecraft are switching to laser technology for data transmission. These optical communication systems can beam information to Earth at speeds up to 100 times faster than conventional radio systems, whilst providing crystal-clear signal quality that doesn't degrade over vast distances. The technology works by encoding data into pulses of laser light, creating what scientists call "optical highways" through space. This breakthrough allows satellites to transmit high-resolution images and complex scientific data in minutes rather than hours, revolutionising how quickly we can access information from the cosmos. Earth's gravity secrets revealed through microscopic measurements NASA's GRACE (Gravity Recovery and Climate Experiment) satellites possess an almost supernatural ability to detect the tiniest changes in Earth's gravitational field. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like 임플란트, 지금 시작하세요 [자세히 보기] 임플란트 더 알아보기 Undo These twin spacecraft can measure gravitational variations as small as one part in a billion, effectively "weighing" different regions of our planet from space. This remarkable sensitivity allows scientists to track invisible phenomena with unprecedented precision. When ice sheets melt in Greenland or groundwater depletes in drought-stricken regions, these satellites detect the resulting gravitational changes before the effects become visible on the surface. The data has transformed our understanding of climate change, revealing that Earth loses approximately 150 billion tonnes of ice annually from its polar regions. Geostationary guardians that never sleep Some NASA satellites perform an incredible balancing act, appearing to hover motionlessly above specific points on Earth's surface. These spacecraft achieve this seemingly impossible feat by matching Earth's rotational speed in what's called a geostationary orbit, positioned precisely 35,786 kilometres above the equator. This strategic positioning allows continuous monitoring of weather patterns, natural disasters, and atmospheric conditions over the same geographical region 24 hours a day. Weather forecasters rely on these stationary sentinels to track hurricane development, monitor volcanic eruptions, and provide early warnings for severe weather events that save countless lives. Cosmic symphony: capturing the sounds of space Space may be a vacuum where sound cannot travel, but NASA satellites have found ingenious ways to "hear" the cosmos. These spacecraft detect electromagnetic waves, solar wind interactions, and planetary magnetic field fluctuations, then convert these signals into audible frequencies that humans can hear. The results are both haunting and beautiful, from the ethereal whistles of Jupiter's magnetosphere to the crackling static of solar storms. These cosmic sounds aren't just curiosities; they provide crucial data about space weather, helping scientists predict potentially dangerous solar activity that could disrupt satellites, power grids, and communication systems on Earth. Planet hunting through stellar shadows NASA's TESS (Transiting Exoplanet Survey Satellite) employs a brilliantly simple yet sophisticated technique to discover worlds beyond our solar system. The satellite monitors hundreds of thousands of stars simultaneously, watching for minute decreases in brightness that occur when planets pass in front of their host stars. These tiny dips in starlight, often less than 1% brightness reduction, reveal not only the existence of exoplanets but also their size, orbital period, and atmospheric composition. TESS has already discovered thousands of potentially habitable worlds, fundamentally changing our understanding of how common planetary systems are throughout the galaxy. Earth's disappearing atmosphere captured in real time NASA satellites have made the startling discovery that Earth's atmosphere is gradually leaking into space, with hydrogen and helium atoms escaping at rates measurable from orbit. This atmospheric escape occurs primarily from the upper atmosphere, where solar radiation provides enough energy for light gases to break free from Earth's gravitational pull. Whilst this process occurs over geological timescales and poses no immediate threat, understanding atmospheric loss helps scientists predict long-term climate evolution and study how other planets may have lost their atmospheres. The research has particularly important implications for understanding Mars's transformation from a potentially habitable world to the arid planet we see today. Robotic mechanics in the void Some of NASA's most advanced satellites are equipped with sophisticated robotic arms and specialized instruments capable of performing delicate operations in the harsh environment of space. These mechanical marvels can capture defunct satellites, remove dangerous space debris, and even perform repairs on other spacecraft—all whilst travelling at thousands of kilometres per hour. The technology represents a crucial step towards sustainable space exploration, as the growing problem of space debris threatens future missions. These robotic systems can extend satellite lifespans, clear orbital pathways, and potentially salvage valuable equipment that would otherwise be lost forever. Rewriting cosmic history Perhaps most remarkably, satellites like the Hubble Space Telescope have fundamentally altered our understanding of the universe itself. By capturing images of galaxies billions of light-years away, essentially looking back in time, these instruments have helped determine that the universe is approximately 13.8 billion years old and expanding at an accelerating rate. This research earned multiple Nobel Prizes and revealed the existence of dark energy, a mysterious force comprising roughly 70% of the universe. Each deep-space image collected by these satellites represents a time machine, showing us how galaxies formed and evolved over cosmic history. 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Time of India
15-05-2025
- Science
- Time of India
South Africa's ground is rising, but it's not volcanic; here's what's really happening
In a dramatic geological change, researchers have discovered that areas of South Africa are rising by as much as 2 millimeters annually. Although this movement was originally thought to be caused by deep mantle processes below the Earth's surface, recent studies indicate a more proximate, surface-based cause: the removal of groundwater. Extended drought has caused extensive groundwater loss, lessening the load on the Earth's crust and allowing it to gradually rise. This finding demonstrates the larger geophysical effect of climate change and drought , revealing that even changes in the water table can quietly remake the Earth's surface. New study reveals how droughts cause Earth's crust to 'spring back' in South Africa A revolutionary study conducted by researchers at the University of Bonn revealed that the apparent "bulging" of the Earth's crust in South Africa is not the result of volcanic or tectonic activity. Instead, it's the crust reacting to a massive loss of groundwater. When droughts become more severe, the weight of water stored in soil and aquifers vanishes, leading the Earth's crust to rise—a process previously misunderstood by geologists. To comprehend this phenomenon, consider compressing a foam ball. Under pressure, the ball compacts; upon pressure release, it returns to its original form. In the same way, the Earth's crust is elastic. When groundwater is drained, the weight bearing down upon the crust lessens and the crust "springs back" partially. This is called elastic rebound—a recognized geophysical response but infrequently ascribed to drought to this degree prior to the present research. GPS and satellite data link drought to ground rise in South Africa Between 2012 and 2020, a GPS array of South African stations had measured vertical land movements up to 6 millimeters. At first mystifying scientists, the observation later led to the development of a new paradigm regarding what was happening below the ground. The GPS data provided precise and reliable observations of vertical displacement, in conflict with the usual expectations regarding deep Earth processes in the area. Findings by NASA's GRACE (Gravity Recovery and Climate Experiment) satellite mission also corroborated the findings. GRACE tracks changes in Earth's gravity field, which can be converted into changes in mass—such as water. Satellite observations independently confirmed a loss of mass where drought was most extreme, namely in soil moisture and groundwater storage. These areas corresponded to the same places where ground uplift had been recorded by GPS, ensuring there to be a close cause-and-effect connection. New findings show drought causes land uplift, not volcanic activity Geophysicists long speculated that rising landmasses in south Africa were being induced by mantle plumes—pipes of hot rock forced upward from below the ground. But the new evidence indicates massive uplift can take place with not even the slightest deep volcanic or tectonic ructions. This is a paradigm shift at the very root of surface deformation science, especially in regions previously considered geologically dormant. The 2015–2019 Cape Town drought had the city hanging in the balance on the eve of "Day Zero"—when municipal water taps would be shut. During that period, researchers noted the most extreme land uplifts ever in the Western Cape. This spatial-time coincidence bears witness to how close the severity of drought and ground deformation are. One of the most significant potential applications of this research is its use in groundwater monitoring. Since land uplift is linearly proportional to water loss, scientists can now use ground vertical motion as a non-destructive and inexpensive alternative for water level measurement. No drilling into the earth is required using this approach, allowing real-time analysis through satellite and GPS. New study shows how climate-driven droughts impact With climate change fueling increased and intensified droughts around the world—from California to the Horn of Africa—the results from South Africa may have far-reaching consequences. This work offers a fresh paradigm for viewing how water poverty impacts the crust of the Earth and presents an important tool for monitoring hydrologic change in risk-prone areas. Also Read | This 400-year-old Catholic saint's body has amazed scientists with its preservation; discover the science behind
