The EU Knowledge Hub on Sea Level Rise’s Assessment Report strives to synthesize the current scientific knowledge on sea level rise and its impacts across local, national, and EU scales to support evidence-based policy and decision-making, primarily targeting coastal areas. This paper complements IPCC reports by documenting the state of knowledge of observed and 21st century projected changes in mean and extreme sea levels with more regional information for EU seas as scoped with stakeholders.

Sea level rise has major impacts in Europe, which vary from place to place and in time, depending on the source of the impacts. Flooding, erosion, and saltwater intrusion lead, via different pathways, to various consequences for coastal regions across Europe. This causes damage to assets, the environment, and people for all three categories of impacts discussed in this paper. The paper provides an overview of the various impacts in Europe.

We address how different ESMs represent vegetation productivity, in terms of carbon fluxes, within the Amazon basin. By statistically assessing the role of climatological and model specific factors that influence vegetation, we showed that surface energy fluxes and the implementation of Phosphorous limitation resulted to be the main drivers of model uncertainties in a future scenario. Reducing these uncertainties allows to increase the reliability of tropical land carbon and climate projections

We propose a discrete multilayer shallow water model based on z-layers which, thanks to the insertion and removal of surface layers, can deal with an arbitrarily large tidal oscillation independently of the vertical resolution. The algorithm is based on a two-step procedure used in numerical simulations with moving boundaries (grid movement followed by a grid topology change, that is, the insertion/removal of surface layers), which avoids the appearance of very thin surface layers.

Cyclone detection and tracking methods (CDTMs) have different approaches in defining and tracking cyclone centers. This leads to disagreements on extratropical cyclone climatologies. We present a new approach that combines tracks from individual CDTMs to produce new composite tracks. These new tracks are shown to correspond to physically meaningful systems with distinctive life stages.

We used a novel database of simulated tropical cyclone tracks to explore whether typhoon-induced storm surges present a future flood risk to low-lying coastal communities around the South China Sea. We found that future climate change is likely to change tropical cyclone behaviour to an extent that this increases the severity and frequency of storm surges to Vietnam, southern China, and Thailand. Consequently, coastal flood defences need to be reviewed for resilience against this future hazard.

This work is focused on the impacts of climate change on a complex water flow system in the southeastern (SE) Baltic Sea, covering the Nemunas river basin and Curonian Lagoon. The results show that lagoon and sea will receive more water coming from the Nemunas. This will lead to a decreased frequency of saltwater inflow to the lagoon, and water will take less time to renew. Water temperatures in the entire lagoon and the SE Baltic Sea will increase steadily, and salinity values will decrease.

Tornadoes represent disruptive and dangerous weather events. The prediction of these small-scale phenomena depends on the resolution of present weather forecast and climatic projections. This work discusses the occurrence of tornadoes in terms of atmospheric variables and provides analytical expressions for their conditional probability. These formulas represent a tool for tornado alert systems and for estimating the future evolution of tornado frequency and intensity in climate projections.

This study examines whether the 1600 Huaynaputina volcano eruption triggered persistent cooling in the North Atlantic. It compares previous paleoclimate simulations with new climate reconstructions from natural proxies and historical documents and finds that the reconstructions are consistent with, but do not support, an eruption trigger for persistent cooling. The study also analyzes societal impacts of climatic change in ca. 1600 and the use of historical observations in model–data comparison.

This paper provides metadata and first analyses of the volc-pinatubo-full experiment of CMIP6-VolMIP. Results from six Earth system models reveal significant differences in radiative flux anomalies that trace back to different implementations of volcanic forcing. Surface responses are in contrast overall consistent across models, reflecting the large spread due to internal variability. A second phase of VolMIP shall consider both aspects toward improved protocol for volc-pinatubo-full.

Relative sea level in Venice rose by about 2.5 mm/year in the past 150 years due to the combined effect of subsidence and mean sea-level rise. We estimate the likely range of mean sea-level rise in Venice by 2100 due to climate changes to be between about 10 and 110 cm, with an improbable yet possible high-end scenario of about 170 cm. Projections of subsidence are not available, but historical evidence demonstrates that they can increase the hazard posed by climatically induced sea-level rise.

In this review we describe the factors leading to the extreme water heights producing the floods of Venice. We discuss the different contributions, their relative importance, and the resulting compound events. We highlight the role of relative sea level rise and the observed past and very likely future increase in extreme water heights, showing that they might be up to 160 % higher at the end of the 21st century than presently.

The city of Venice relies crucially on a good storm surge forecast to protect its population and cultural heritage. In this paper, we provide a state-of-the-art review of storm surge forecasting, starting from examples in Europe and focusing on the Adriatic Sea and the Lagoon of Venice. We discuss the physics of storm surge, as well as the particular aspects of Venice and new techniques in storm surge modeling. We also give recommendations on what a future forecasting system should look like.

The 1809 eruption is one of the most recent unidentified volcanic eruptions with a global climate impact. We demonstrate that climate model simulations of the 1809 eruption show generally good agreement with many large-scale temperature reconstructions and early instrumental records for a range of radiative forcing estimates. In terms of explaining the spatially heterogeneous and temporally delayed Northern Hemisphere cooling suggested by tree-ring networks, the investigation remains open.

In coastal regions, floods can arise through concurrent drivers, such as precipitation, river discharge, storm surge, and waves, which exacerbate the impact. In this study, we identify hotspots of compound flooding along the southern coast of the North Atlantic Ocean and the northern coast of the Mediterranean Sea. This regional assessment can be considered a screening tool for coastal management that provides information about which areas are more predisposed to experience compound flooding.

This study finds how and why five state-of-the-art global climate models with interactive stratospheric aerosols differ when simulating the aftermath of large volcanic injections as part of the Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP). We identify and explain the consequences of significant disparities in the underlying physics and chemistry currently in some of the models, which are problems likely not unique to the models participating in this study.

The problem of the optimization of ocean monitoring networks is tackled through the implementation of data assimilation techniques in a numerical model. The methodology has been applied to the tide gauge network in the Lagoon of Venice (Italy). The data assimilation methods allow identifying the minimum number of stations and their distribution that correctly represent the lagoon's dynamics. The methodology is easily exportable to other environments and can be extended to other variables.