GeoRoundup: the highlights of EGU Journals published during September!

Each month we feature specific Divisions of EGU and during the monthly GeoRoundup we put the journals that publish science from those Divisions at the top of the Highlights section. During this month, we are featuring Seismology (SM) and Climate: Past, Present & Future (CL). They are represented by the journals Geoscientific Model Development (GMD), Solid Earth (SE), Climate of the Past (CP), Earth System Dynamics (ESD), and Weather and Climate Dynamics (WCD).

Geoscientific Model Development

flat10MIP: an emissions-driven experiment to diagnose the climate response to positive, zero and negative CO₂ emissions – 05 September 2025
This study investigates how climate models warm in response to simplified carbon emissions trajectories, refining the understanding of climate reversibility and commitment. Metrics are defined for warming response to cumulative emissions and for the cessation of emissions or ramp-down to net-zero and net-negative levels. Results indicate that previous concentration-driven experiments may have overstated the Zero Emissions Commitment due to emissions rates exceeding historical levels.

Earth System Dynamics

A climate suitability index for species distribution modelling applied to terrestrial arthropods in the Mediterranean region – 01 September 2025
Climate change threatens biodiversity, especially that of arthropods, by altering species’ habitats and ecological roles. This study presents a proof of concept for a novel index that models species distributions based on climatic niches, using regional climate model data and focusing on Mediterranean arthropods. The index enables quick assessments of species’ climate resilience and offers potential applications for projecting ecological impacts of future climate changes.

Multi-centennial climate change in a warming world beyond 2100 – 09 September 2025
A new 10-member ensemble simulation with the state-of-the-art Earth system model was employed to study the long-term climate response to sustained greenhouse warming through to the year 2500. The findings show that the projected changes in the forced mean state and internal variability during 2101–2500 differ substantially from the 21st-century projections, emphasizing the importance of multi-century perspectives for understanding future climate change and informing effective mitigation strategies.

ESD Ideas: Climate tipping is not instantaneous – the duration of an overshoot matters – 15 September 2025
Climate tipping points are not committed upon crossing critical thresholds in global warming, as is often assumed. Instead, it is possible to temporarily overshoot a threshold without causing tipping, provided the duration of the overshoot is short. In this Idea, we demonstrate that restricting the time over 1.5 °C would considerably reduce tipping point risks.

Food trade disruption after global catastrophes – 30 September 2025
The global food trade system can handle small disturbances, but large disasters could cause major disruptions. We looked at how nuclear war or severe infrastructure loss would affect global trade in key crops. Both would be catastrophic, but a nuclear war would cause more severe disruptions, with many countries losing most of their food imports. Both scenarios highlight the need for better preparation to protect global food security.

Weather and Climate Dynamics

CYCLOPs: a Unified Framework for Surface Flux-Driven Cyclones Outside the Tropics – 04 September 2025
Storms strongly resembling hurricanes are sometimes observed to form well outside the tropics, even in polar latitudes. They behave capriciously, developing very rapidly and then dying just as quickly. We show that strong dynamical processes in the atmosphere can sometimes cause it to become much colder locally than the underlying ocean, creating the conditions for hurricanes to form but only over small areas and for short times. We call the resulting storms “CYCLOPs”.

Learning predictable and informative dynamical drivers of extreme precipitation using variational autoencoders – 26 September 2025
Large-scale atmospheric dynamics modulate the occurrence of extreme events and can improve their prediction. We present a generative machine learning method to identify key dynamical drivers of an impact variable in the form of targeted circulation regimes. Applied to extreme precipitation in Morocco, we show that these targeted regimes are more predictive of the impact while preserving their own predictability and physical consistency.

Atmospheric Measurement Techniques

The Arctic Weather Satellite radiometer – 22 September 2025

Biogeosciences

Organic soils can be CO₂ sinks in both drained and undrained hemiboreal peatland forests – 14 September 2025

Peatland development reconstruction and complex biological responses to permafrost thawing in Western Siberia – 20 September 2025

Multidecadal trends in CO₂ evasion and aquatic metabolism in a large temperate river – 23 September 2025

Impacts of eutrophication and deoxygenation on the sediment biogeochemistry in the Sea of Marmara – 24 September 2025

Technical note: Pondi – a low-cost logger for long-term monitoring of methane, carbon dioxide, and nitrous oxide in aquatic and terrestrial systems – 27 September 2025

Physiological responses to ultra-high CO₂ levels in an evergreen tree species – 28 September 2025

Earth Surface Dynamics

Biomechanical parameters of marram grass (Calamagrostis arenaria) for advanced modeling of dune vegetation – 05 September

Multi-centennial climate change in a warming world beyond 2100 – 09 September 2025