All articles tagged with #ocean warming
Global sea levels are rising at an accelerating pace driven mainly by warming oceans expanding water, with glaciers and ice sheets contributing increasingly; improved satellite and tide-gauge measurements close a long-standing discrepancy between observations and known causes, and scientists warn sea levels will keep rising for centuries due to climate inertia.
A Southampton-led study in Science Advances identifies a three-stage sequence behind Antarctic sea-ice collapse to record lows since 2015: warm Circumpolar Deep Water rising toward the surface, intensified mixing that rapidly melts ice (especially East Antarctica), and a self‑reinforcing cycle that prevents new ice from forming. The East Antarctica melt is ocean-heat-driven, while West Antarctica is amplified by cloud-driven warming. If this persistent low-ice state continues, the Southern Ocean could become a long‑term driver of global warming, with destabilized currents and potential impacts on sea level and climate.
A Science Advances study identifies a three-stage cascade—strengthening circumpolar winds pushing warmer, saltier water to the surface, surface water becoming saltier and more buoyant, and feedbacks that prevent new ice formation—that has driven Antarctica’s sea ice to a multi‑year decline, with record lows in 2022 and 2023. East Antarctica and West Antarctica show different drivers (deep-ocean heat vs. atmospheric warming). The loss of sea ice exposes ice sheets to waves and warmer waters, reduces sunlight reflection, and could accelerate global warming; if the trend continues into the 2030s, the climatic and sea‑level implications could be substantial.
New research identifies a three-phase cascade behind Antarctic sea-ice loss: stronger westerly winds push warmer, saltier deep water to the surface to melt ice; warming and stratification keep heat near the surface, hindering new ice formation; and a feedback loop from declining ice locks the region into a prolonged low-ice state, with East and West Antarctica affected differently and potential global warming implications if the trend persists.
Scientists in northeast Japan identified Physalia mikazuki, a previously unknown man-o-war species, on Gamo Beach in Miyagi Prefecture—representing the northernmost record for the genus. The species differs morphologically (gas-filled pneumatophore, multiple primary tentacles, yellow gastrozooids) and was confirmed as a distinct species by genetic analysis. Its appearance here is linked to northward drift driven by winds and currents, a consequence of warming oceans. The discovery carries public-safety implications due to venomous stings and highlights the need for ongoing monitoring of Physalia in Japanese waters.
As the ocean warms, mesothermic predators like great white sharks and certain tuna must burn more energy to stay warm, forcing them to relocate to cooler waters and cope with dwindling prey; sensor data show that a one-ton warm-bodied shark may struggle to stay in water above about 62.6°F (17°C), highlighting overheating risk alongside ongoing threats from overfishing and bycatch.
A Nature Ecology & Evolution study finds chronic ocean warming steadily reduces marine biomass, with fish declines of about 7.2% per 0.1°C per decade and up to nearly 20% in a single year; while marine heatwaves trigger temporary population booms that mask long-term losses, signaling governance and fisheries risks as warming continues.
Scientists drilling into Thwaites Glacier with a hot-water borehole faced their instruments getting stuck about three-quarters of the way down and had to abandon the deployment, but the data recovered reveal warm, turbulent waters beneath the ice driving sub-ice melt. The findings improve understanding of the glacier’s instability, and researchers plan to return to continue studying it, given its potential to raise global sea levels by about 65 cm if it destabilizes.
Researchers from BAS and KOPRI partially lowered instruments under Antarctica’s Thwaites Glacier to study warm, subglacial waters; the mooring got stuck as the borehole refroze and time/weather forced an abandonment, but the team still obtained valuable measurements to inform future efforts.
The world's oceans experienced record-breaking heat for the ninth consecutive year in 2025, driven by rising greenhouse gas emissions, leading to severe weather events, melting ice sheets, and threats to marine life, with no end in sight unless global emissions are drastically reduced.
The Earth's oceans have warmed for the ninth consecutive year in 2025, absorbing vast amounts of heat that contribute to climate change, extreme weather, and threats to marine ecosystems like coral reefs, with the warming penetrating as deep as 2,000 meters and likely to persist for centuries. Immediate action to reduce greenhouse gases could stabilize or reverse this trend.
Since 2018, the world's oceans have been absorbing record amounts of heat, with 2025 experiencing the highest heat absorption ever recorded, primarily due to climate change. This ongoing heat intake, equivalent to multiple atomic bombs, is a key indicator of global warming, affecting both surface and deep ocean temperatures, and will have long-lasting impacts on the planet.
The disappearance of the deep-sea 'zombie worm' (Osedax), which feeds on whale bones, may indicate declining oxygen levels in the ocean caused by warming, potentially disrupting important deep-sea ecosystems and leading to species loss.
A recent study confirms that melting ice and ocean warming significantly contribute to rising sea levels, with an average increase of about 3 millimeters per year, highlighting the urgent need for climate mitigation efforts and providing valuable data for future climate projections.
A new study warns that rising ocean temperatures threaten Prochlorococcus, Earth's most abundant photosynthetic microbe, which produces nearly a third of the planet's oxygen. The microbe's optimal temperature range is 19-28°C, and temperatures above 30°C significantly reduce its growth, potentially leading to a decline in its population and impacting global oxygen levels and marine food webs. The study highlights the importance of understanding microbial responses to climate change and the potential shift in oceanic ecosystems.