Description: In 2021, the United Nations Environment Programme (UNEP) recognized chemical pollution as a planetary crisis tantamount to climate change and biodiversity decline. (1) In an important next step, the international community agreed in March 2022 on establishing an independent, intergovernmental science–policy panel on chemicals, waste, and pollution prevention (hereafter termed “the Panel”). (2) This Panel will take its place among two other intergovernmental bodies, the Intergovernmental Panel on Climate Change (IPCC) (3) and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). (4) Now is a crucial time for establishing the Panel, following a process facilitated by UNEP to negotiate the Panel’s scope, functions, and institutional design, with the ambition to formally establish the Panel in 2024. As a group of international scientists working on chemical pollution, we applaud this milestone of progress to initiate the establishment of a panel for chemicals, waste, and pollution prevention. At the beginning of the negotiating process, we would like to highlight the following 10 critical aspects for consideration in determining the settings of the Panel.

Description: A high-resolution study of the MIS 12/MIS 11 transition and the MIS 11 (430 to 376 kyr) coccolithophore assemblages at Ocean Drilling Program Site 977 was conducted to reconstruct the paleoceanographic and climatic changes in the Alboran Sea from the variability in surface water conditions. The nannofossil record was integrated with the planktonic oxygen and carbon stable isotopes, the Uk'37 Sea Surface Temperature (SST), and at the opal phytolith content at the studied site during the investigated interval. The comparison suggests an association of the upwelling dynamics with the variability of the North Atlantic Oscillation-like (NAO-like) phase. Overall, the results provide evidences of the important role of atmospheric circulation patterns in the North Atlantic region for controlling phytoplankton primary production and oceanographic circulation dynamics in the Western Mediterranean during MIS 11.

Description: Sea Surface Temperature recontrution on site U1385

Description: Past sea surface temperatures (SST) in the northern and southern areas of the South China Sea have been reconstructed for the past 220 kyr using the UK37 alkenone index. The SST profiles follow the glacial/interglacial pattern exhibiting differences between Last Glacial Maximum and Holocene that are 1°-3°C larger than those observed at the same latitudes in the Atlantic and Pacific Oceans. In Termination I both planktonic foraminiferal d18O and SST exhibit well-defined Bølling-Allerød and Younger Dryas events with temperature differences between both periods of 0.8° and 0.4°C in north and south, respectively. SSTs record a constant north-south difference of 1°C in the interglacials and nearly 2.5°C in the glacial stages. These differences define two distinct climatic and water circulation patterns that correspond with glacial/interglacial sea level oscillations which opened and closed water exchange with the tropical Indo-Pacific Ocean through the present Sunda Shelf

Description: Sea surface temperatures (SSTs) recorded by alkenones and oxygen isotopes in the Alboran basin are used here to describe, at an unprecedented fine temporal resolution, the present interglaciation (PIG, initiated at 11.7 ka BP), the last interglaciation (LIG, onset approximately at 129 ka) and respective deglaciations. Similarities and dissimilarities in the progression of these periods are reviewed in comparison with ice cores and stalagmites. Cold spells coeval with the Heinrich events (H) described in the North Atlantic include multi-decadal scale oscillations not previously obvious (up to 4 °C in less than eight centuries within the stadials associated with H1 and H11, ca 133 ka and 17 ka respectively). These abrupt oscillations precede the accumulation of organic rich layers deposited when perihelion moves from alignment with NH spring equinox to the summer solstice, a reference for deglaciations. Events observed during the last deglaciation at 17 ka, 14.8 ka and 11.7 ka are reminiscent of events occurred during the penultimate deglaciation at ca 136 ka, 132 ka and 129 ka, respectively. The SST trend during the PIG is no more than 2 °C (from 20 °C to 18 °C; up to -0.2 °C/ka). The trend is steeper during the LIG, i.e. up to a 5 °C change from the early interglaciation to immediately before the glacial inception (from 23 °C to 18 °C; up to -0.4 °C/ka). Events are superimposed upon a long term trend towards colder SSTs, beginning with SST maxima followed by temperate periods until perihelion aligned with the NH autumn equinox (before ca 5.3 ka for the PIG and 121 ka for the LIG). A cold spell of around eight centuries at 2.8 ka during the PIG was possibly mimicked during the LIG at ca 118 ka by a SST fall of around 1 °C in a millennium. These events led interglacial SST to stabilise at around 18 °C. The glacial inception, barely evident at the beginning ca 115 ka (North Atlantic event C25, after perihelion passage in the NH winter solstice), culminated with a SST drop of at least 2 °C in two millennia (event C24, ca 111 ka). The Little Ice Age (0.7 ka) also occurred after the latest perihelion passage in the NH winter solstice and could be an example of how a glacial pre-inception event following an interglaciation might be.

Description: This study analyzes coccolithophore abundance fluctuations (e.g., Emiliania huxleyi, Gephyrocapsa specimens, and Florisphaera profunda) in core MD01-2444 sediment strata retrieved at the Iberian Margin, northeastern Atlantic Ocean. Coccolithophores are calcareous nannofossils, a major component of the oceanic phytoplankton, which provide information about past ecological and climatological variability. Results are supported by data on fossil organic compounds (sea surface temperatures, alkenones, and n-hexacosan-1-ol index) and geochemical analyses (benthic d13Ccc and planktonic d18Occ isotopes). Three scenarios are taken into account for this location at centennial-scale resolution over the last 70,000 years: the Holocene and the stadial and interstadial modes. The different alternatives are described by means of elements such as nutrients; upwelling phenomena; temperatures at surface and subsurface level; or the arrival of surface turbid, fresh, and cold waters due to icebergs, low sea level, increased aridity, and dust. During the Holocene, moderate primary productivity was observed (mainly concentrated in E. huxleyi specimens); surface temperatures were at maxima while the water column was highly ventilated by northern-sourced polar deep waters and warmer subsurface, nutrient-poor subtropical waters. Over most of the last glacial stadials, surface productivity weakened (higher F. profunda and reworked specimen percentages and lower diunsaturated and triunsaturated C37 alkenones); the arrival of cold Arctic surface waters traced by tetraunsaturated C37 peaks and large E. huxleyi, together with powerful ventilated southern-sourced polar deep waters, disturbed, in all likelihood, the delicate vertical equilibrium while preventing significant upwelling mixing. Finally, during the last glacial interstadials (lower F. profunda percentages, nonreworked material, and higher diunsaturated and triunsaturated C37 alkenones) a combined signal is observed: warm surface temperatures were concurrent with generally low oxygenation of the deep-sea floor, moderate arrival of northern-sourced deep waters, and subsurface cold, nutrient-rich, recently upwelled waters, probably of polar origin; these particular conditions may have promoted vertical mixing while enhancing surface primary productivity (mainly of Gephyrocapsa specimens).