Updated estimates of 2024 ice thickness, the surface elevation losses in the last years and simulations of mass balance and evolution (using the Instructed Glacier Model) for the three largest Pyrenean glaciers strongly suggest that by 2034 the Pyrenees will be ice-free. If extreme summers like 2022 and 2023 recur, this could happen even earlier. We show that by 2030, 94% (from 0.22 to 0.01 km2) of the ice in Monte Perdido, 91% (from 0.22 to 0.05 km2) of the ice in Ossoue and 79% of the ice in Aneto (from 0.34 to 0.06 km2) will have melted under the RCP4.5 scenario; these numbers are 83%, 72% and 57% under a committed ice loss scenario, meaning that only 0.05, 0.12 and 0.12 km2 of ice will remain, respectively. In 2034, most likely they will have completely disappeared under the three considered scenarios (RCP 4.5, ‘committed ice loss’ and extreme 2022 year in a loop). The loss of these glaciers is a harbinger for what will happen in many other mountain regions.

Measurements of the radiocarbon (14C) content of subannual wood cellulose samples over the 1963 bomb spike have revealed an apparent delay between the increase in atmospheric radiocarbon content and that of wood cellulose. This delay is apparent in both coniferous and deciduous tree species and is of a magnitude of approximately 4 weeks. The delay in wood cellulose 14C change as measured in a Sitka spruce from Washington state, USA, was previously used to estimate the relative influence of tree physiological effects contra environmental effects. We repeated the measurements with the increased measurement precision of today’s AMS systems and compare the new results to the ones of a Scots pine tree from Trondheim, central Norway and a white oak from Oregon state, USA. The results challenge the assumption that the 14C tree ring records directly show the atmospheric 14C concentration of a homogeneous, zonally well-mixed atmosphere. Instead, the apparent 1963 delay reflects local influences of the ecosystem and tree physiology. The 1963/1964 data allows for exploratory modeling of the effects of biospheric decay CO2 and local environmental influences assuming the absence of stored photosynthates from the previous year. Compared to the 10–30% contribution from biospheric CO2, the effects of delayed incorporation of carbon into the wood cellulose and the effect of stored photosynthate are small in the conifers. Highly detailed 14C records of stem cellulose can, in combination with stable isotope studies, contribute to our understanding of variability of the local carbon cycle, climate, and the environment.

The Lower Jurassic (Toarcian) Posidonienschiefer Formation of southwestern Germany is a classic konservat lagerstätte, yielding some of the world’s best-preserved fossils of marine vertebrates, including ichthyosaurs, thalattosuchian crocodylomorphs, plesiosaurs and fishes. Despite numerous studies concentrating on the taphonomy of ichthyosaurs in this formation, less taphonomic work has focussed on the thalattosuchians of the assemblage. Multiple thalattosuchian species displaying a wide range of body sizes have been recovered. We investigated indicators for seafloor arrival position in thirteen Macrospondylus bollensis and one Platysuchus multiscrobiculatus specimens representing various body sizes using three-dimensional (3D) photogrammetric models. False-colour depth maps were used to interpret the relative topography (depth level) of bone penetration into the sediment and were aligned on the XY plane, making them parallel to the stratigraphic plane. Our results show both headfirst and non-headfirst seafloor arrivals in observed specimens, with headfirst seafloor arrivals exhibiting deeply buried skulls, displacement of select cervical vertebrae and/or characteristic fractures in the cranium and mandible. We (1) interpret seafloor landing types in teleosauroids; (2) recognize and list specific characteristics that are consistently attributed to either a headfirst or non-headfirst seafloor arrival; (3) discuss possible factors that may have contributed to these features, such as body shape and size, substrate and velocity; and (4) provide a new definition for headfirst seafloor arrival that can be readily attributed to other marine vertebrates from various formations. Lastly, our results show that observers must carefully consider how historical specimens might have been prepared, as this may influence taphonomic interpretations.

Baltic Sea ice coverage was modelled using a sea-ice thermodynamics and dynamics model coupled with a three-dimensional (3-D) PM3D hydrodynamic model. The validation for 1958–2007 showed the modelled maximum ice extents (MIEs) agree well with observations (r = 0.97) and the ice thickness less so, but satisfactory for most stations (r > 0.8). This enabled the production of cumulative ice thickness (CIT) maps and the determination of the spatial variation in sea-ice extent in the Baltic over the analysed period for four air temperature scenarios with a constant value reduction. This showed the spatial sensitivity of ice cover dynamics to temperature changes and allowed to distinct regions with different impact of change in temperature on CIT. The simulation for temperature of 2°C lower than 1958–2007 was consistent with the reconstruction of MIEs in the entire Baltic Sea for the end of the Little Ice Age (LIA) (1721–1860). For the western Baltic, the compliance was highest for temperature reduced by 3°C and 4°C. This indicates that climatic conditions may have differed between individual regions of the Baltic during the LIA, and the air temperature anomaly in the western Baltic may have been greater than indicated by previous studies

Jellyfish are widely distributed throughout the world’s oceans. However, understanding jellyfish species’ distributions remains poor. Here, we addressed this knowledge gap by applying an approach that uses citizen science observations to inform collection of samples which then undergo molecular analysis. Doing so allowed us to confirm the presence of the jellyfish Cyanea purpurea in the waters of Hong Kong SAR for the first time. Due to morphological overlap in Cyanea species, DNA analysis confirmed specimen identification. Samples were taken from 19 jellyfish individuals for subsequent DNA analysis. Ten samples (53%) were confirmed as C. purpurea, two samples (10%) were identified as Cyanea nozakii, and seven samples (37%) were not able to be identified. The combined application of citizen science and DNA analysis has proven effective in confirming the presence of C. purpurea in Hong Kong waters. This approach of using citizen science observations to inform the collection of samples for subsequent molecular analysis could be transferrable to other similar situations in which identification based solely on morphology is insufficient, potentially enhancing our ability to recognise species occurrence.