Pollution

Stefan Rahmstorf, Professor of Physics os the Ocean at the University of Potsdam since 2000, presents a colloquium on the risks associated with the destabilization of the Atlantic Meridional Overturning Circulation (AMOC) and its potential consequences for the global climate.

Recent simulations using the Community Earth System Model (CESM) indicate that a tipping event of the Atlantic Meridional Overturning Circulation (AMOC) would cause Europe to cool by several degrees. This AMOC tipping event was found under constant pre-industrial greenhouse gas forcing, while global warming likely limits this AMOC-induced cooling response. Here, we quantify the European temperature responses under different AMOC regimes and climate change scenarios. A strongly reduced AMOC state and intermediate global warming (C, Representative Concentration Pathway 4.5) has a profound cooling effect on Northwestern Europe with more intense cold extremes. The largest temperature responses are found during the winter months and these responses are strongly influenced by the North Atlantic sea-ice extent. Enhanced North Atlantic storm track activity under an AMOC collapse results in substantially larger day-to-day temperature fluctuations. We conclude that the (far) future European temperatures are dependent o

There’s frustration among researchers that falling pH levels in seas around the globe are not being taken seriously enough, and that until the buildup of CO2 is addressed, the consequences for marine life will be devastating

Have you ever thought about what would happen if all life in the ocean disappeared? A recent study explores this extreme scenario to understand how ocean biology shapes the past, present, and future climate. The ocean plays a critical role in regulating Earth's climate. It is a massive carbon store that absorbs about 25% of human-caused emissions and thus helps maintain a relatively low CO2 level in the atmosphere. But what would happen if all marine life—from the tiniest plankton to the largest whales—disappeared? A recent study delves into this extreme scenario to uncover the crucial role that ocean biology plays in mitigating climate change.

Sascha is a U.K.-based staff writer at Live Science. She holds a bachelor’s degree in biology from the University of Southampton in England and a master’s degree in science communication from Imperial College London. Her work has appeared in The Guardian and the health website Zoe. Besides writing, she enjoys playing tennis, bread-making and browsing second-hand shops for hidden gems.

The ocean ecosystem is a vital component of the global carbon cycle, storing enough carbon to keep atmospheric CO2 considerably lower than it would otherwise be. However, this conception is based on simple models, neglecting the coupled land-ocean feedback. Using an interactive Earth system model, we show that the role ocean biology plays in controlling atmospheric CO2 is more complex than previously thought. Atmospheric CO2 in a new equilibrium state after the biological pump is shut down increases by more than 50% (163 ppm), lower than expected as approximately half the carbon lost from the ocean is adsorbed by the land. The abiotic ocean is less capable of taking up anthropogenic carbon due to the warmer climate, an absent biological surface pCO2 deficit and a higher Revelle factor. Prioritizing research on and preserving marine ecosystem functioning would be crucial to mitigate climate change and the risks associated with it.

Antarctica's remote and mysterious current has a profound influence on the climate, food systems and Antarctic ecosystems. Can we stop it weakening by 2050?

The Antarctic Circumpolar Current (ACC) is the world's strongest ocean current and plays a disproportionate role in the climate system due to its role as a conduit for major ocean basins. This current system is linked to the ocean's vertical overturning circulation, and is thus pivotal to the uptake of heat and CO2 in the ocean. The strength of the ACC has varied substantially across warm and cold climates in Earth's past, but the exact dynamical drivers of this change remain elusive. This is in part because ocean models have historically been unable to adequately resolve the small-scale processes that control current strength. Here, we assess a global ocean model simulation which resolves such processes to diagnose the impact of changing thermal, haline and wind conditions on the strength of the ACC. Our results show that, by 2050, the strength of the ACC declines by ∼20% for a high-emissions scenario. This decline is driven by meltwater from ice shelves around Antarctica, which is exported to lower latit

The Atlantic Meridional Overturning Circulation (AMOC), vital for northwards heat transport in the Atlantic Ocean, is projected to weaken owing to global warming1, with significant global climate impacts2. However, the extent of AMOC weakening is uncertain with wide variation a …

... An “acid” test of our interpretation will be provided by the 2025 global temperature: unlike the 1997-98 and 2015-16 El Ninos, which were followed by global cooling of more than 0.3°C and 0.2°C, respectively, we expect global temperature in 2025 to remain near or above the 1.5°C level. Indeed, the 2025 might even set a new record despite the present weak La Nina. There are two independent reasons. First, the “new” climate forcing due to reduction of sulfate aerosols over the ocean remains in place, and, second, high climate sensitivity (~4.5°C for doubled CO2) implies that the warming from recently added forcings is still growing significantly.

To date, the ocean has largely been treated as an afterthought in global climate strategies, sidelined in favor of more visible priorities like renewable energy and reducing carbon emissions. But ocean-based solutions are indispensable to the green transition and must be funded accordingly.

The idea that the AMOC is headed to collapse is very controversial, but it is clearly weakening. If the circulation did collapse, the consequences on both sides of the Atlantic Ocean would be immense—including large changes in temperature and a spike in weather-related disasters.

Oceanographer Stefan Rahmstorf explains why Amoc breakdown could be catastrophic for both humans and marine life

A new study suggests that the Gulf Stream was stronger during the last ice age due to more powerful winds, indicating that future changes in wind patterns could weaken the Gulf Stream, affecting European climate and North American sea levels. This research enhances our understanding of the Atlantic Meridional Overturning Circulation (AMOC) and its vulnerability to climate change.

For many of us the climate crisis mainly calls to mind rising global temperatures, but the crisis goes far beyond this – we are at risk of pushing our planet across climate ‘tipping points,’ critical thresholds where small changes can lead to abrupt and irreversible shifts in the Earth’s climate system. One major element in climate tipping is a huge system of ocean currents, the Atlantic Meridional Overturning Circulation (AMOC), which is responsible for Europe's relatively mild climate. Past climate patterns show that these currents can switch abruptly between today’s vigorous flow and a much weaker flow state. A future shutdown would have potentially devastating consequences in Europe and around the world.

Elizabeth Kolbert on a record-breaking rise in global sea-surface temperatures, which suggests that scientists may not understand how fast the climate is changing.

Ce rapport analyse les obstacles et leviers à la lumière de projets inspirants en matière d'adaptation des villes à l'élévation du niveau de la mer dans le Pacifique.

Rapid ocean warming and unusually hot winter days recorded as human-made global heating combines with El Niño

Scientists now have a better understanding of the risks ahead and a new early warning signal to watch for.

Collapse in system of currents that helps regulate global climate would be at such speed that adaptation would be impossible

Disruption of the Atlantic Meridional Overturning Current could freeze Europe, scorch the tropics and increase sea level rise in the North Atlantic. The tipping point may be closer than predicted in the IPCC’s latest assessment.

Anthropogenic emissions drive global-scale warming yet the temperature increase relative to pre-industrial levels is uncertain. Using 300 years of ocean mixed-layer temperature records preserved in sclerosponge carbonate skeletons, we demonstrate that industrial-era warming began in the mid-1860s, more than 80 years earlier than instrumental sea surface temperature records. The Sr/Ca palaeothermometer was calibrated against ‘modern’ (post-1963) highly correlated (R2 = 0.91) instrumental records of global sea surface temperatures, with the pre-industrial defined by nearly constant (<±0.1 °C) temperatures from 1700 to the early 1860s. Increasing ocean and land-air temperatures overlap until the late twentieth century, when the land began warming at nearly twice the rate of the surface oceans. Hotter land temperatures, together with the earlier onset of industrial-era warming, indicate that global warming was already 1.7 ± 0.1 °C above pre-industrial levels by 2020. Our result is 0.5 °C higher than IPCC estim

Daily Sea Surface Temperature

RealClimate: For various reasons I'm motivated to provide an update on my current thinking regarding the slowdown and tipping point of the Atlantic Meridional Overturning Circulation (AMOC). I attended a two-day AMOC session at the IUGG Conference the week before last, there's been interesting new papers, and in the light of that I have been changing

Record sea surface temperatures suggest the Earth is headed for ‘uncharted territory’ in terms of sea level rise, coastal flooding and extreme weather

La Niña is present.* Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean. The tropical Pacific atmosphere is consistent with La Niña. La Niña is expected to continue into the winter, with equal chances of La Niña and ENSO-neutral during January-March 2023. In February-April 2023, there is a 71% chance of ENSO-neutral.*

The new study shows that every increment of sea level rise will cover more than twice as much land as older models predicted, and marks another advance in providing more accurate models of rising seas

An international team of scientists painstakingly gathered data from more than 50 years of seagoing scientific drilling missions to conduct a first-of-its-kind study of organic carbon that falls to the bottom of the ocean and gets drawn deep inside the planet.

In the past 50 years, the oceans have absorbed more than 90% of the excess heat caused by our carbon dioxide emissions, with one ocean absorbing the vast majority.

Shallow deposits of frozen methane beneath oceans may be more vulnerable to thawing than previously known.

Ce policy brief propose une série de recommandations et appelle au renforcement des connaissances en amont de l’implantation d’éoliennes en mer. Il prône une meilleure connaissance du fonctionnement des écosystèmes marins, des impacts cumulés des activités humaines existantes et des impacts sur le milieu marin du changement climatique, afin de guider la planification notamment dans le choix des zones d’implantation des éoliennes.

Restaurant menus across the West Coast of Canada will soon see an influx of squid and sardine dishes, while the popular sockeye salmon makes a slow exit. As it turns out, climate change may have something to do with this.

A new study describes a period of rapid global climate change in an ice-capped world much like the present—but 304 million years ago. Within about 300,000 years, atmospheric carbon dioxide levels doubled, oceans became anoxic, and biodiversity dropped on land and at sea.

Fresh water cycles from ocean to air to clouds to rivers and back to the oceans. This constant shuttling can give us the illusion of certainty. Fresh water will always come from the tap. Won’t it? Unfortunately, that’s not guaranteed. Climate change is shifting where the water cycle deposits water on land, with drier areas becoming drier still, and wet areas becoming even wetter.

Water vapor is Earth’s most abundant greenhouse gas. It’s responsible for about half of Earth’s greenhouse effect — the process that occurs when gases in Earth’s atmosphere trap the Sun’s heat. Greenhouse gases keep our planet livable. Without them, Earth’s surface temperature would be about 59 degrees Fahrenheit (33 degrees Celsius) colder. Water vapor is also a key part of Earth’s water cycle: the path that all water follows as it moves around Earth’s atmosphere, land, and ocean as liquid water, solid ice, and gaseous water vapor.

As the world starts to seriously entertain the possibility of commercially mining the deep sea for valuable metals, it’s worth taking a closer look at the claims used to justify its potentially long-lived impacts.

Door de opwarming van het oceaanwater moeten walvissen noodgedwongen naar gevaarlijke gebieden trekken om eten te vinden. Ook voor andere zeezoogdieren wordt het moeilijker overleven in de warmere oceanen.

Een gevolg van de opwarmende oceanen is dat er minder vis te vangen zal zijn. Warmer water zorgt namelijk voor kleinere en minder mobiele vissen, en bedreigt zo onze voedselzekerheid.

Climate scientists have detected warning signs of the collapse of the Gulf Stream, one of the planet’s main potential tipping points. The research found “an almost complete loss of stability over the last century” of the currents that researchers call the Atlantic Meridional Overturning Circulation (AMOC). The currents are already at their slowest point in at least 1,600 years, but the new analysis shows they may be nearing a shutdown.

The Atlantic Ocean's current system, an engine of the Northern Hemsiphere's climate, could be weakening to such an extent that it could soon bring big changes to the world's weather, a scientific study said on Thursday.

The Atlantic Meridional Overturning Circulation (AMOC), a major ocean current system transporting warm surface waters toward the northern Atlantic, has been suggested to exhibit two distinct modes of operation. A collapse from the currently attained strong to the weak mode would have severe impacts on the global climate system and further multi-stable Earth system components. Observations and recently suggested fingerprints of AMOC variability indicate a gradual weakening during the last decades, but estimates of the critical transition point remain uncertain.

A Pandora’s box of environmental disasters has been opened, threatening the ability of the natural world to recover and humanity to survive. From devastating fires and storms to the emergence of deadly new viruses, it’s hard to deny the terrifying reality of climate change.

The shocking collapse of a 12-storey building in the Miami area last week has raised questions as to the role played by the climate crisis, and whether the severe vulnerability of south Florida to the rising seas may lead to the destabilization of further buildings in the future.

Officials prepare to elevate streets despite financial shortfalls, amid recognition that not every home can be save. Long famed for its spectacular fishing, sprawling coral reefs and literary residents such as Ernest Hemingway, the Florida Keys is now acknowledging a previously unthinkable reality: it faces being overwhelmed by the rising seas and not every home can be saved.

Around the world, dozens of ingenious projects are trying to ‘trick’ the ocean into absorbing more CO2. But critics warn of unforeseen consequences

A new report, published on 14 March, 2021 in the Royal Swedish Academy of Sciences’ journal Ambio, points out that humanity is hurtling towards destruction unless we have the collective wisdom to change course quickly.

Sea ice land. 7 Tipping points are analysed here. Climate tipping points, elements of the Earth system in which small changes in global temperature can kick off reinforcing loops that ‘tip’ a system into a profoundly different state, accelerating heat waves, permafrost thaw, and coastal flooding — and, in some cases, fueling more warming.

La Chine a qualifié mardi "d'irresponsable" la décision du Japon de rejeter à la mer les eaux issues de la centrale nucléaire de Fukushima, accidentée en 2011.

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Le gouvernement japonais a officialisé ce mardi sa décision de rejeter dans l’océan Pacifique plus d’un million de tonnes d’eau traitée mais toujours radioactive de la centrale nucléaire accidentée de Fukushima Daiichi. Une opération qui pourrait s’étaler sur plusieurs décennies, malgré l’opposition de pays voisins, des ONG environnementales et des pêcheurs locaux.

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Le 11 mars 2011, l’archipel est secoué par le plus important séisme enregistré, de magnitude 9 sur l’échelle de Richter. 51 minutes plus tard, un tsunami frappe les côtes causant plus de 18 000 morts et provoquant des dégâts considérables.

A new analysis shows the world's oceans were the warmest in 2019 than any other time in recorded human history, especially between the surface and a depth of 2,000 meters. The study, conducted by an international team of 14 scientists from 11 institutes across the world, also concludes that the past 10 years have been the warmest on record for global ocean temperatures, with the past five years holding the highest record.

Des tonnes de plastique sont produites chaque année, et la plupart des déchets finissent dans les océans et les mers comme la Méditerranée. Un des gros problèmes de cette pollution aux plastiques n'est pas ce que nous pouvons voir à l'œil nu – les sacs ou les emballages – mais bien ce que nous ne pouvons pas voir : les petits morceaux appelés "microplastiques", et aussi les molécules qui les composent.

The persistent march of a warming climate is seen across a multitude of continuous, incremental changes. CO2 levels in the atmosphere. Ocean heat content. Global sea level rise. Each creeps up year after year, fuelled by human-caused greenhouse gas emissions.

Toutes les eaux d'évacuation, d'origine domestique, industrielle ou hospitalière, sont pourtant traitées - du moins dans les pays développés - par des stations d'épuration. Mais ces installations, qui éliminent les pollutions azotées, carbonées ou phosphorées, n'ont dans leur cahier des charges aucune obligation concernant les résidus médicamenteux. Ceux-ci ne sont que "partiellement" détruits,

The accelerating thaw of Antarctica might drive sea levels up by more than five metres by 2300 unless governments act quickly to cut greenhouse gas emissions, a UN report said on Wednesday.

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