Recent  

Current trends on CO₂ emissions increase the probability of an overshoot scenario, in which temperatures exceed the targets of the Paris Agreement and are brought back afterwards with a net-negative emission strategy. This work analyses how the climate after the overshoot would differ from the climate before, linking large scale non-reversibility mechanisms to changes in regional climates, and identifying those regions more impacted by changes on temperature and precipitation extremes.

Based on a series of storm-resolving greenhouse warming simulations conducted with the AWI-CM3 model at 9 km global atmosphere, 4–25 km ocean resolution, we present new projections of regional climate change, modes of climate variability and extreme events. The 10-year-long high resolution simulations for the 2000s, 2030s, 2060s, 2090s were initialized from a coarser resolution transient run (31 km atmosphere) which follows the SSP5-8.5 greenhouse gas emission scenario from 1950–2100 CE.

The ocean is forced at the surface by a heat flux and freshwater flux. This noise can influence long-term ocean variability and the large scale circulation. Here we study noise characteristics in reanalysis data for these fluxes. We try to capture the noise characteristics by using several noise models and compare these to state-of-the-art climate models. A point wise noise model performs better than the climate models and can be used as forcing in ocean-only models to study.

Land-cover and land management changes (LCLMCs) can alter climate even in intact areas, causing carbon changes in remote areas. This study is the first to assess these effects, finding they substantially alter global carbon dynamics, changing terrestrial stocks by up to dozens of gigatons. These results are vital for scientific and policy assessments, given the expected role of LCLMCs in achieving the Paris Agreement’s goal to limit global warming below 1.5 °C.

Flows in the ocean are driven either by atmospheric forces or by small-scale internal disturbances that are inherently chaotic. We use computer simulation results to show that these chaotic oceanic disturbances can attain spatial scales large enough to alter the motion of Earth’s pole of rotation. Given their size and unpredictable nature, the chaotic signals are a source of uncertainty when interpreting observed year-to-year polar motion changes in terms of other processes in the Earth system.

Spatially compounding wind and precipitation (CWP) extremes can lead to severe impacts on society. We find that concurrent climate variability modes favor the occurrence of such wintertime spatially compounding events in the Northern Hemisphere, and can even amplify the number of regions and population exposed. Our analysis highlights the importance of considering the interplay between variability modes to improve risk management of such spatially compounding events.

In recent decades, we have witnessed abnormally hot summers and frequent weather extremes globally. These are clear signs of global warming and climate change. A constant increase in atmospheric carbon dioxide (CO₂) is a major driver of these changes. We propose an algorithm for near-real-time detection of terrestrial areas with CO₂ sources and sinks. This algorithm could aid in developing new methods of natural CO₂ reduction and exploring ecosystem responses to disturbances.

For tipping points at low levels of global warming, overshoots of the threshold are becoming increasingly likely. Importantly, for some systems, tipping can still be avoided provided the forcing is reversed sufficiently quickly. Conditions for a mitigation window, that would avoid tipping, depend on system uncertainties. We highlight the need to account for uncertainty in the threshold location and other system features when designing climate mitigation strategies that avoid tipping.

This study investigated the computational benefits of using multiple models of varying cost and accuracy to quantify uncertainty in the mass change of Humboldt Glacier, Greenland, between 2007 and 2100 using a single climate change scenario. Despite some models being incapable of capturing the local features of the ice flow fields, using multiple models reduced the error in the estimated statistics by over an order of magnitude when compared to an approach that only used a single accurate model.

Past research has shown that the North Atlantic ocean circulation reacts strongly to global land cover changes. Using Earth system model simulations featuring idealized forestation and deforestation of North America, this study shows that the North Atlantic ocean is highly sensitive to upstream land cover changes. Anomalies in air temperature over land propagate downstream and modify ocean-to-atmosphere heat fluxes over the North Atlantic through altering cold air outbreak frequency.

Climate change threatens biodiversity, especially arthropods, which can significantly impact the stability of ecosystems. This study introduces an index to assess habitat suitability for Mediterranean arthropods using climate model data. The index can indicate how climate change could affect arthropod habitats, provided there is an abundant initial dataset of observations for the species of interest.

We present a high-resolution paleogeographic reconstruction of the Baltic Sea for the Holocene period by combining eustatic sea-level change, glacio-isostatic movement, and sediment dynamics. In the north-eastern part, morphological change is dominated by regression caused by post-glacial rebound that outpaces the eustatic sea level rise, whereas a transgression together with active sediment erosion/deposition constantly shape the coastal morphology in the south-eastern part.

Our study examines potential changes in heatwaves in Central Europe due to global warming, using the 2019 summer heatwave as an example. By producing high-resolution storylines, we offer insights into how future heatwaves might spread, persist longer, and where stronger or weaker temperature increases may occur. This research helps understand regional thermodynamic responses and highlights the importance of local strategies to protect communities from future heat events.

We evaluated two Lagrangian moisture tracking tools, WaterSip and UTrack, and compared them against the WRF model with Water Vapor Tracers. Our results show that UTrack, which relies on evaporation and precipitable water data, has a slightly better agreement with WRF-WVTs than WaterSip, based on specific humidity data. Implementing simple physics-based changes substantially improved both methodologies, reducing discrepancies by about 50 % and narrowing the the disparities among all approaches.

Climate sensitivity and aerosol forcing are central quantities in climate science, uncertain and contribute to the spread in climate predictions. To constrain these, we use observations of temperature and ocean heat content and prior knowledge of radiative forcings over the industrialized period. The estimates are sensitive to how the aerosol cooling has evolved over the latter part of the 20^th century, and a strong aerosol forcing trend in the 1960s–1970s is not supported by our analysis.

Using the satellite-based climate data record CLARA-A3 spanning 1982–2020 and ERA5 reanalysis, we present climate regimes that are favourable or unfavourable for solar energy applications. We show that the favourable climate regimes are emerging over much of Europe during spring and early summer for solar energy exploitation.

The Holocene Peatland Model (HPM) is a widely used peatland model to understand and predict long-term peatland dynamics. Here, we test whether the HPM can predict Sphagnum litterbag decomposition rates from oxic to anoxic conditions. Our results indicate that decomposition rates change more gradually from oxic to anoxic conditions and may be underestimated under anoxic conditions, possibly because the effect of water table fluctuations on decomposition rates is not considered.

The climate of the last 3 Myr varies between cold and warm periods. Numerous independent mechanisms have been proposed to explain this, however no effort has been made to study their competing effects. Here we present a simple but physically motivated model that includes these mechanisms in a modular way. We find that the main trigger is the displacement of the lithosphere due to the ice thickness evolution, but reproducing the climate records additionally requires the natural darkening of ice.

Explosive Cyclones and Atmospheric Rivers are two main drivers of extreme weather in Europe. In this study, we investigate their joint changes in future climates over the North Atlantic. Our results show that both the concurrence of these events and the intensity of atmospheric rivers increase by the end of the century across different future scenarios. Furthermore, explosive cyclones associated with atmospheric rivers are longer-lasting and deeper than those without atmospheric rivers.

Glaciers in the northern hemisphere outside Greenland are losing mass at roughly half the Greenland ice sheet's (GrIS) rate. Still, this is usually not included in the freshwater input data for numerical ocean circulation models. Also, the submarine melt of glaciers (outside the ice sheets) has not been quantified yet. We tackle both issues by using a numerical glacier model's output as additional freshwater for the ocean model and by using the ocean model's output to quantify submarine melt.