Latest news with #TohoUniversity
NDTV
3 days ago
- Science
- NDTV
Earth Will Lose Its Oxygen: Scientists Warn Of A Rapid Countdown
A recent study reveals that Earth's oxygen-rich atmosphere, vital for complex life, is expected to last approximately one billion more years. Increasing solar radiation will reduce atmospheric carbon dioxide, impairing photosynthesis and leading to a sharp decline in oxygen levels. The study that was published in Nature Geoscience said that this deoxygenation could occur rapidly, rendering Earth inhospitable to most life forms. The findings also suggest oxygen may not be a permanent biosignature on habitable planets, impacting the search for extraterrestrial life. "For many years, the lifespan of Earth's biosphere has been discussed based on scientific knowledge about the steady brightening of the sun and the global carbonate-silicate geochemical cycle. One of the corollaries of such a theoretical framework is a continuous decline in atmospheric CO2 levels and global warming on geological timescales. Indeed, it is generally thought that Earth's biosphere will come to an end in the next 2 billion years due to the combination of overheating and CO2 scarcity for photosynthesis. If true, one can expect that atmospheric O2 levels will also eventually decrease in the distant future. However, it remains unclear exactly when and how this will occur," environmental scientist Kazumi Ozaki from Toho University in Japan said when the study was published. To examine how Earth's atmosphere will evolve in the future, Ozaki and Christopher Reinhard, Associate Professor at Georgia Institute of Technology, constructed an Earth system model which simulates climate and biogeochemical processes. Because modelling future Earth evolution intrinsically has uncertainties in geological and biological evolutions, a stochastic approach was adopted, enabling the researchers to obtain a probabilistic assessment of the lifespan of an oxygenated atmosphere. Ozaki ran the model more than 400 thousand times, varying the model parameters, and found that Earth's oxygen-rich atmosphere will probably persist for another one billion years before rapid deoxygenation renders the atmosphere reminiscent of early Earth before the Great Oxidation Event around 2.5 billion years ago. "The atmosphere after the great deoxygenation is characterised by elevated methane, low levels of CO2, and no ozone layer. The Earth system will probably be a world of anaerobic life forms," says Ozaki. Earth's oxygen-rich atmosphere represents an important sign of life that can be remotely detected. However, this study suggests that Earth's oxygenated atmosphere would not be a permanent feature and that the oxygen-rich atmosphere might only be possible for 20-30% of the Earth's entire history as an inhabited planet. Oxygen (and photochemical byproduct, ozone) is the most accepted biosignature for the search for life on exoplanets, but if we can generalise this insight to Earth-like planets, then scientists need to consider additional biosignatures applicable to weakly oxygenated and anoxic worlds in the search for life beyond our solar system.
Arab Times
4 days ago
- Science
- Arab Times
Study predicts oxygen collapse will end most life on Earth in a billion years
JAPAN, June 2: Earth's atmosphere, currently rich in oxygen and capable of supporting complex life, won't remain this way forever. Scientists predict that in about a billion years, the planet will undergo a dramatic shift — returning to a state rich in methane and extremely low in oxygen, similar to conditions before the Great Oxidation Event (GOE) roughly 2.4 billion years ago. Although this transformation is far off, when it begins, the change will happen relatively quickly, according to a 2021 study by environmental scientist Kazumi Ozaki of Toho University in Japan and Earth scientist Chris Reinhard of the Georgia Institute of Technology. 'For many years, the lifespan of Earth's biosphere has been discussed based on scientific knowledge about the steadily brightening Sun and global carbonate-silicate geochemical cycles,' said Ozaki. 'One consequence of this framework is a steady decline in atmospheric CO₂ and eventual global warming over geological timescales.' Using detailed models of Earth's biosphere — factoring in the Sun's increasing luminosity and corresponding drops in atmospheric CO₂ — the researchers determined that lower carbon dioxide levels will lead to fewer photosynthesizing organisms. This would significantly reduce the production of oxygen, ultimately pushing atmospheric oxygen levels to a point roughly a million times lower than today. 'The drop in oxygen is very, very extreme,' Reinhard told New Scientist. 'We're talking around a million times less oxygen than there is today.' According to the study, this atmospheric shift is likely to occur before Earth reaches a "moist greenhouse" state, where water vapor dominates the upper atmosphere and the planet begins to lose its surface water. This means that oxygen-dependent life will likely die out long before Earth becomes too hot for oceans to exist. Despite its long timeline, the study has pressing implications for astrobiology. The findings suggest that atmospheric oxygen may not be a permanent feature of habitable planets. This challenges the current focus on oxygen as a key biosignature in the search for life on exoplanets. The research, part of NASA's NExSS (Nexus for Exoplanet System Science) project, highlights the importance of considering alternative biosignatures in the hunt for extraterrestrial life. 'The atmosphere after the great deoxygenation will be characterized by high methane, low CO₂, and no ozone layer,' said Ozaki. 'Earth will likely become a world dominated by anaerobic life forms.' According to the team's models—based on nearly 400,000 simulations—the oxygen-rich phase of Earth's habitable era may represent only 20 to 30 percent of the planet's total lifespan. While human and other oxygen-dependent life will eventually vanish, microbial life adapted to low-oxygen conditions is expected to persist long after.
Yahoo
4 days ago
- Health
- Yahoo
An Extreme Drop in Oxygen Will Eventually Suffocate Most Life on Earth
For now, complex life flourishes on our planet thanks to its supply of oxygen. But Earth's atmosphere wasn't always like it is today, and scientists predict that in the future, it will revert back to one that's rich in methane and low in oxygen. Breathe easy though. This won't happen for probably another billion years or so. But when the change comes, it's going to happen fairly rapidly, according to research published in 2021. This shift will take the planet back to something like the state it was in before what's known as the Great Oxidation Event (GOE) around 2.4 billion years ago. "For many years, the lifespan of Earth's biosphere has been discussed based on scientific knowledge about the steadily brightening of the sun and global carbonate-silicate geochemical cycle," environmental scientist Kazumi Ozaki from Toho University in Japan said when the study was published. "One of the corollaries of such a theoretical framework is a continuous decline in atmospheric CO2 levels and global warming on geological timescales." The researchers say that atmospheric oxygen is unlikely to be a permanent feature of habitable worlds in general, which has implications for our efforts to detect signs of life further out in the Universe. "The model projects that a deoxygenation of the atmosphere, with atmospheric O2 dropping sharply to levels reminiscent of the Archaean Earth, will most probably be triggered before the inception of moist greenhouse conditions in Earth's climate system and before the extensive loss of surface water from the atmosphere," the team explained in their paper. At that point it'll be the end of the road for human beings and most other life forms that rely on oxygen to get through the day, so let's hope we figure out how to get off the planet at some point within the next billion years. To reach their conclusions, the researchers ran detailed models of Earth's biosphere, factoring in changes in the brightness of the Sun and the corresponding drop in carbon dioxide levels, as the gas gets broken down by increasing levels of heat. Less carbon dioxide means fewer photosynthesizing organisms such as plants, which would result in less oxygen. Scientists have previously predicted that increased radiation from the Sun would wipe ocean waters off the face of our planet within about 2 billion years, but the model here – based on an average of just under 400,000 simulations – says the reduction in oxygen is going to kill off life first. "The drop in oxygen is very, very extreme," Earth scientist Chris Reinhard, from the Georgia Institute of Technology, told New Scientist. "We're talking around a million times less oxygen than there is today." What makes the study particularly relevant to the present day is our search for habitable planets outside of the Solar System. Increasingly powerful telescopes are coming online, and scientists want to be able to know what they should be looking for in the reams of data these instruments are collecting. It's possible that we need to be hunting for other biosignatures besides oxygen to have the best chance of spotting life, the researchers say. Their study was part of the NASA NExSS (Nexus for Exoplanet System Science) project, which is investigating the habitability of planets other than our own. According to the calculations run by Ozaki and Reinhard, the oxygen-rich habitable history of Earth could end up lasting for just 20-30 percent of the planet's lifespan as a whole – and microbial life will carry on existing long after we are gone. "The atmosphere after the great deoxygenation is characterized by an elevated methane, low-levels of CO2, and no ozone layer," said Ozaki. "The Earth system will probably be a world of anaerobic life forms." The research was published in Nature Geoscience. An earlier version of this article was published in March 2021. The Ocean Is Getting Darker, Threatening All That Lives Within Your Salad Could Be Carrying Microplastics From Soil Into Your Body UN Warns: High Odds We'll Exceed 1.5°C Temp Rise by 2029
Time of India
14-05-2025
- Science
- Time of India
When will life on Earth end? Scientists now have the ‘exact date'
Scientists Just Predicted the Date Life on Earth Will Vanish Forever A groundbreaking study led by researchers from Toho University, using NASA's planetary modeling, has predicted a dramatic shift in Earth's atmosphere that could render life as we know it impossible. According to the research, Earth's oxygen will disappear in approximately one billion years. This prediction, published in the scientific journal Nature Geoscience, marks a significant development in understanding the planet's atmospheric evolution. The study ran 400,000 simulations to explore how Earth's atmosphere might evolve as the sun continues to age and intensify. While this drastic transformation may be far in the future, understanding the mechanisms behind it offers essential insights into planetary science and the future of Earth's biosphere. Scientists found Earth's 'expiration date', and it's sooner than you think The study titled "The Future Lifespan of Earth's Oxygenated Atmosphere" outlines a future where oxygen becomes scarce due to natural planetary changes. Led by Kazumi Ozaki, an assistant professor at Toho University in Tokyo, Japan, the researchers examined the factors contributing to atmospheric changes over geological timescales. The role of the Sun One of the core factors leading to oxygen depletion is the sun's inevitable aging process. As the sun ages, it will gradually become hotter and brighter. This increase in solar radiation will significantly impact Earth's climate, leading to a series of irreversible changes: Water evaporation : The heightened temperatures will cause more rapid evaporation of Earth's water bodies, increasing atmospheric water vapor levels. Temperature rise : Surface temperatures will escalate, pushing the planet towards conditions unsuitable for sustaining life. Carbon cycle disruption : The heating will weaken the carbon cycle, a critical process that regulates atmospheric carbon dioxide (CO₂). Vegetation decline : As the carbon cycle falters, plant life will begin to die off, halting oxygen production through photosynthesis. Earth's atmosphere to lose oxygen The research revealed that as the carbon cycle deteriorates, the atmosphere will revert to a composition reminiscent of early Earth, characterized by high levels of methane and low oxygen. This transformation mirrors the state before the Great Oxidation Event—a period when Earth's atmosphere became rich in oxygen due to the proliferation of photosynthetic organisms. Key findings from the simulation Rapid deoxygenation : The simulations predict that Earth's oxygen will decline rapidly after reaching a critical threshold, potentially within a span of a few thousand years. Methane dominance : The oxygen loss will be accompanied by a significant increase in methane levels, reverting to a primordial atmospheric state. Uninhabitable conditions : As oxygen becomes scarce, most complex aerobic life forms, including humans, will find survival impossible. Factors contributing to oxygen depletion on Earth The decline in atmospheric oxygen is not solely due to solar changes but also involves complex geochemical interactions: Global carbonate-silicate cycle : This cycle, which helps balance CO₂ through weathering and sedimentation, will slow down, further contributing to atmospheric instability. CO₂ scarcity : As CO₂ levels fall, plants will no longer be able to perform photosynthesis efficiently, leading to a rapid decline in oxygen production. Thermal stress on biosphere : The rising temperatures will push Earth's ecosystems beyond their resilience limits, causing mass extinction and reduced biological activity. Earth's oxygen clock ticking faster than expected Earlier scientific models suggested that Earth's biosphere would last up to two billion years, primarily due to overheating and the eventual depletion of CO₂ necessary for photosynthesis. However, this new research narrows the timeframe, suggesting a much earlier end to oxygen production. Kazumi Ozaki emphasized that while the eventual demise of Earth's biosphere was acknowledged, pinpointing the timing and the precise process of deoxygenation remained elusive. This study, using advanced supercomputer simulations, provides a clearer understanding by simulating numerous potential scenarios. The implications for future research Understanding the lifespan of Earth's oxygenated atmosphere has profound implications for both planetary science and astrobiology. Researchers now aim to investigate how similar processes might occur on exoplanets, particularly those orbiting older stars, to gauge their habitability. Key research questions moving forward Can life adapt? While simple anaerobic organisms might survive, complex life would face extinction. Scientists are examining how life might adapt under drastically altered atmospheric conditions. Comparative planetology : Could planets in other solar systems undergo similar atmospheric shifts as their stars age? Technological interventions : Though purely speculative, future technology might aim to artificially maintain Earth's oxygen levels or migrate human life to other planets.
Metro
13-05-2025
- Science
- Metro
Exact date life on Earth will end, according to a supercomputer
Hiyah Zaidi Published May 12, 2025 2:45pm Link is copied Comments One day the Earth will die and human life as we know it will go with it. But, the question is, when will this happen, and how will this come about? A team of experts have set out to answer the question with the help of a supercomputer by playing out the future of our planet 400,000 times. Here's what you need to know... (Picture: Getty) Researchers from Toho University used planetary modelling from Nasa to create simulations tracking how Earth's atmosphere is likely to evolve. And it found that in the distant future the Earth will run out of oxygen (Picture: Getty) The simulations predicted that in one billion years (the year 1,000,002,021 to be exact) the air we breathe will disappear, making survival impossible. As the Sun gets older, it will become hotter and brighter, slowly affecting Earth's delicate climate which is finely balanced to support life (Picture: Getty) Water will begin to evaporate, cloud cover will move and surface temperatures will rise. Then, this increase in heat will weaken the carbon cycle, which will end up killing plants as they can no longer effectively turn sunlight into oxygen in a process known as photosynthesis. Without plants, oxygen will no longer be produced (Picture: Getty) As the oxygen levels plummet, the atmosphere would become something like it was before human life existed. This was a state of high methane, which although theoretically could sustain life, it would be very different to any life we know so far. So, to find when this would happen, the researchers ran the computer simulation over 400,000 times, varying different aspects of the model each time (Picture: Getty) Kazumi Ozaki, Assistant Professor at Toho University, said: 'For many years, the lifespan of Earth's biosphere has been discussed based on scientific knowledge about the steady brightening of the Sun and global carbonate-silicate geochemical cycle. One of the corollaries of such a theoretical framework is a continuous decline in atmospheric CO2 levels and global warming on geological timescales. It's generally thought Earth's biosphere will come to an end in two billion years due to the combination of overheating and CO2 scarcity for photosynthesis. If true, one can expect atmospheric O2 levels will also eventually decrease in the distant future. However, it remains unclear exactly when and how this will occur' (Picture: Getty) So, what will happen in one billion years? The researchers say that after this time 'rapid deoxygenation' will occur, and our atmosphere will be reminiscent of early Earth before the Great Oxidation Event, 2.5 billion years ago. What caused the Great Oxidation Event is unknown but it thought that single-celled organisms are largely responsible for it (Picture: Getty)
