English references

Several, more recent global warming projections in the coupled model intercomparison project 6 contain extensions beyond year 2100–2300/2500. The Atlantic meridional overturning circulation (AMOC) in these projections shows transitions to extremely weak overturning below the surface mixed layer (<6 Sv; 1 Sv = 106 m3 s−1) in all models forced by a high-emission (SSP585) scenario and sometimes also forced by an intermediate- (SSP245) and low-emission (SSP126) scenario. These extremely weak overturning states are characterised by a shallow maximum overturning at depths less than 200 m and a shutdown of the circulation associated with North Atlantic deep water formation. Northward Atlantic heat transport at 26°N decreases to 20%–40% of the current observed value. Heat release to the atmosphere north of 45°N weakens to less than 20% of its present-day value and in some models completely vanishes, leading to strong cooling in the subpolar North Atlantic and Northwest Europe. In all cases, these transitions to a

For decades, the surface of the polar Southern Ocean (south of 50°S) has been freshening—an expected response to a warming climate. This freshening enhanced upper-ocean stratification, reducing the upward transport of subsurface heat and possibly contributing to sea ice expansion. It also limited the formation of open-ocean polynyas. Using satellite observations, we reveal a marked increase in surface salinity across the circumpolar Southern Ocean since 2015. This shift has weakened upper-ocean stratification, coinciding with a dramatic decline in Antarctic sea ice coverage. Additionally, rising salinity facilitated the reemergence of the Maud Rise polynya in the Weddell Sea, a phenomenon last observed in the mid-1970s.

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

Sudden cut in pollution in 2020 meant less shade from sun and was ‘substantial’ factor in record surface temperatures in 2023, study finds

Today’s oceans are a tumult of engine roar, artificial sonar and seismic blasts that make it impossible for marine creatures to hunt or communicate. We could make it stop, so why don’t we?

Germany’s Rhine, one of Europe’s key waterways, is just days away from being closed to commercial traffic because of very low levels caused by drought, authorities and industry have warned. Crucially, the impending crisis could lead energy companies to cut their output, one of the country’s biggest gas companies has said.

The electric car will be an important part of a green transition. But our main focus should be moving toward green collective mobility like public transportation and away from the dominance of personally owned cars.

Global shipping is moving invasive species around the world. Can world governments agree on necessary preventative measures?

Over 25 million tonnes of CO2 – equivalent to the total CO2 emissions of Denmark¹ – are exempt from the EU’s proposed carbon price for shipping, a new Transport & Environment (T&E) study shows. Arbitrary exemptions of ships such as those servicing oil and gas facilities, as well as yachts, will undermine the EU’s shipping law and let millions of tonnes of emissions off the hook, says T&E.

one-third of all food produced each year is squandered or spoiled before it can be consumed. Research also suggests that high-income countries waste as much food as sub-Saharan Africa produces. This food waste then ends up in landfills to rot – which releases greenhouse gases. And when this is combined with the amount of energy it takes to produce, manufacture, transport and store this food, it contributes a staggering 3 billion tonnes of carbon dioxide to our planet.

Major airlines have claimed in recent years that they can offset emissions by supporting forest conservation projects, yet a new investigation reveals that the systems used are deeply flawed. One of the main offset accreditors, Verra, whose ‘avoided’ deforestation scheme is criticised in the investigation for lacking credibility