Present-day mass redistribution increases the total ocean mass and, on average, causes the ocean bottom to subside elastically. Therefore, barystatic sea level rise is larger than the resulting global mean geocentric sea level rise, observed by satellite altimetry and GPS-corrected tide gauges. We use realistic estimates of mass redistribution from ice mass loss and land water storage to quantify the resulting ocean bottom deformation and its effect on global and regional ocean volume change estimates.

The legacy and reach of anthropogenic influence is most clearly evidenced by its impact on the most remote and inaccessible habitats on Earth. Here we identify extraordinary levels of persistent organic pollutants in the endemic amphipod fauna from two of the deepest ocean trenches (>10,000 metres). Contaminant levels were considerably higher than documented for nearby regions of heavy industrialization, indicating bioaccumulation of anthropogenic contamination and inferring that these pollutants are pervasive across the world’s oceans and to full ocean depth.

Intermittent disruptions to rainfall patterns and intensity over the Pacific Ocean lasting up to B 1 year have major impacts on severe weather, agricultural production, ecosystems, and disease within the Pacific, and in many countries beyond. The frequency with which major disruptions to Pacific rainfall occur has been projected to increase over the 21st century, in response to global warming caused by large 21st century greenhouse gas emissions.

The majority of naturally occurring freshwater on small islands is groundwater, which is primarily recharged by precipitation. Recharge rates are therefore likely to be impacted by climate change. Freshwater resources on small islands are particularly vulnerable to climate change because they are limited in size and easily compromised. Here we have compiled available aquifer system characteristics and water-use data for 43 small island developing states distributed worldwide, based on local expert knowledge, publications and regional data sets.

A new study has warned that oxygen levels in some oceans are beginning to fall and widespread evidence of the trend will likely be evident from 2030 onwards.

Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate.

Core isotope measurements in the equatorial Pacific Ocean reveal that although atmospheric dust deposition during the last ice age was higher than today’s, the productivity of the equatorial Pacific Ocean did not increase; this may have been because iron-enabled greater nutrient consumption, mainly in the Southern Ocean, reduced the nutrients available in the equatorial Pacific Ocean, and hence also productivity there.

Marine plastic pollution is an ever-increasing problem that demands immediate mitigation and reduction plans. Here, a model based on satellite-tracked buoy observations and scaled to a large data set of observations on microplastic from surface trawls was used to simulate the transport of plastics floating on the ocean surface from 2015 to 2025, with the goal to assess the optimal marine microplastic removal locations for two scenarios: removing the most surface microplastic and reducing the impact on ecosystems, using plankton growth as a proxy.

The latest El Niño weather phenomenon is now the biggest and most powerful it has ever been since records began.

Coral reefs are essential to ocean health, but dangerous coral bleaching is occurring more often and more widely due to warmer water, scientists report