All articles tagged with #carbon cycle
New research using rhenium isotopes from a 183-million-year-old Welsh rock core shows that oxidation of eroding organic carbon amplified the Toarcian warming, indicating organic-carbon weathering can release CO2 and strengthen climate feedbacks beyond volcanic CO2; the exact magnitude and relevance to modern climate remain uncertain.
A Nature study across 50 rivers on China's Qinghai–Tibet Plateau shows that thawing permafrost accelerates rock weathering, which consumes atmospheric CO2 and can offset or even exceed river CO2 emissions in some catchments, suggesting geological processes may partly counterbalance thaw-induced carbon release.
A global study maps arbuscular mycorrhizal fungal networks using 16,669 soil cores and AI, revealing dense underground hyphal networks that connect most land plants and drive carbon and nutrient exchange. Wild grasslands host the densest networks, with topsoil containing a large share of global fungal biomass, and croplands showing about 50% lower density. If laid end-to-end, the hyphae would stretch about 68 quadrillion miles (110 quadrillion kilometers), roughly 10% of the Milky Way’s width, highlighting their key role in the carbon cycle and informing biodiversity, climate, and agricultural strategies.
Scientists using machine learning and high-resolution imaging mapped the planet's vast underground networks of arbuscular mycorrhizal fungi, finding filaments totaling about 68 quadrillion miles and storing around 300 megatons of carbon—roughly 4-6 times the carbon contained by all humans—highlighting fungi's key role in plant nutrition and global carbon cycling.
A sweeping look at Earth’s deep ocean—from twilight mid-water zones to hydrothermal vents—reveals an enormous, little-understood ecosystem that fuels global climate and hosts bizarre life forms powered by chemical energy. It traces a century of exploration (Challenger, Alvin) and explains how mid-water migrations drive major carbon transport, while warning that growing seabed‑mining interests, especially for manganese nodules in the Clarion–Clipperton Zone, threaten fragile, slow‑growing communities and untapped biotechnologies. The piece argues for protecting these environments even as they hold clues to life’s origins and future innovations.
Rocks show that early Mars hosted liquid water, but whether it was warm remains debated. The planetary dynamo likely died between about 4.2 and 3.7 billion years ago, removing the magnetic shield and enabling solar wind to strip gas—an escape process MAVEN measured, especially during solar storms. Some carbon dioxide may have been stored in minerals like siderite, so not all missing air left to space. The balance between atmospheric loss and crustal storage is still uncertain, and better palaeomagnetic dating and additional sampling are needed to pin down Mars’ climate history. The cold desert is settled, but the path to understanding how it happened is ongoing.
Harvard researchers simulate the Sturtian glaciation (about 717–660 million years ago) as a cycle of glaciation and thaw driven by carbon-cycle feedbacks: volcanic CO₂ input and basalt weathering lowered CO₂ to trigger ice cover, while ongoing volcanism and reduced weathering during ice cover allowed CO₂ to build and melt, repeating for ~56 million years—reconciling the geological record and the survival of early aerobic life, with implications for exoplanet climates.
A University of Washington study finds that an Earth-sized planet needs a substantial surface water inventory—about 20–50% of Earth’s ocean volume—to maintain long-term habitability. On very dry worlds, the carbon cycle can break down, allowing CO2 to build up and heat the planet, potentially rendering it uninhabitable despite being in the habitable zone. Venus serves as a nearby analog, illustrating how small water differences can dramatically impact climate. The work suggests many desert-like exoplanets thought promising for life may actually be poor candidates and informs future observations and Venus missions.
A new study using computer models shows that Earth's plate tectonics—especially mid-ocean ridges and continental rifts—play a larger role in shaping global climate than previously thought by guiding the deep carbon cycle: carbon stored in seafloor sediments is buried and later released via subduction, driving greenhouse and icehouse periods over the last 540 million years and challenging the view that volcanic arcs are the primary CO2 source, with implications for future climate models.
Scientists using the NEPTUNE observatory monitored Barkley Canyon for nearly 10 years and found an unexpected absence of decay activity around whale bones and wood, lacking typical scavengers and bone-eating organisms. The results suggest ocean deoxygenation and expanding oxygen minimum zones are suppressing the deep-sea recyclers (Osedax, Xylophaga), potentially slowing organic decomposition and nutrient cycling with ripple effects on the broader food web.
A new international study links a long-term drop in ocean calcium since the dinosaurs’ extinction to changes in marine carbon storage. Lower calcium altered how shells and skeletons form and bury carbon, effectively pulling CO2 from the atmosphere and cooling the planet by up to about 15–20°C over millions of years, with seafloor spreading slowing as a key driver of the reduced calcium input to seawater.
New computer-model research shows Earth’s plate movements—especially mid-ocean ridges and continental rifts—have been a major driver of long-term carbon cycling. Carbon stored in seafloor rocks is released or sequestered as plates move and subduct, helping to trigger greenhouse or icehouse climates over the last 540 million years. Historically, volcanic arcs were thought to dominate carbon release, but the study finds that divergent plate boundaries played a larger role, with arc emissions rising mainly in the last ~120 million years due to the evolution of planktic calcifiers.
New computer-based reconstructions of 540 million years show that the movement of Earth’s plates—especially mid-ocean ridges and continental rifts that drive carbon into and out of the oceans, and the subsequent subduction of carbon-rich sediments—have played a bigger role in driving greenhouse and icehouse climates than volcanic arcs alone. The deep-sea carbon cycle acts as a key regulator of atmospheric CO2, influencing past and future climate and informing climate models that consider tectonic processes alongside human emissions.
Coral reefs have played a crucial role in regulating Earth's climate for over 250 million years by influencing ocean alkalinity and carbon absorption, with their rise and fall affecting climate recovery times and marine evolution; current reef decline due to human activity may impact this natural climate regulation, but recovery would take thousands to hundreds of thousands of years.
A new study uncovers a feedback mechanism in Earth's carbon cycle that could cause global warming to overshoot and trigger an ice age, suggesting Earth's climate system can overreact and potentially plunge the planet into deep freeze, especially under past conditions of low atmospheric oxygen. However, current higher oxygen levels may dampen this effect, but the risk remains if warming continues. The findings highlight the importance of limiting ongoing climate change.