2023

1. [Dance 2023] As papers pile up, journal editors are struggling to find willing referees.
   Peer review

2. [Escribano 2023] The transition from a fossil fuel to a renewable energy regime also implies a change in the geopolitical equilibrium, with the eventual emergence of winners and losers.
   Geopolitica y cambio climático

3. [García-García et al. 2023] Hot temperature extremes are changing in intensity and frequency. Quantifying these changes is key for developing adaptation strategies [1]. The conventional approach to study changes in hot extremes is based on air temperatures. However, hydrology [2] and many biogeo- chemical processes, e.g. decomposition of organic material and release of CO2 [3]- are more sensitive to soil rather than air temperature. In this study, we show that soil hot extremes are increasing faster than air hot extremes by 0.7◦C/Decade in intensity and twice as fast in frequency on average over Central Europe. Furthermore, we identify soil temperature as a factor in the soil moisture–temperature feed- back. During dry conditions, increases in net radiation yield higher soil temperature and a consequent release of sensible heat while latent heat flux is constrained by soil moisture deficits. The release of sen- sible heat from soils leads to increases in air temperature and vapour pressure deficit that may further dry out and warm up the soil. This study further highlights the contribution of soil moisture–temperature feedback to the evolution of hot extremes in a warming climate. The rapid increase in soil heat extremes shown in these results may have important implications for climate and ecological risk applications.
   Land air coupling, climate change

4. [Hopcroft et al. 2023] Abstract: The pre-industrial Holocene provides the backdrop for the emergence of civilisations and the starting point of anthropogenic climate change. Several reconstructions show an early Holocene warming that was followed by cooling for several thousand years before Industrialisation. In contrast climate simulations show warming throughout the Holocene. Whilst reconstructed trends over ocean can be reconciled with warming through either seasonality or uncertainties, a consistent explanation for cooling trends over some land areas is missing. We present a suite of transient Holocene climate model simulations with a coupled general circulation model and show that a widespread mid- to late-Holocene cooling emerges over some regions of the northern hemisphere with the inclusion of anthropogenic land-use. This is mostly because in regions of prescribed late Holocene deforestation, the simulated early to mid-Holocene is characterised by a lower albedo than the late Holocene. Whilst this cooling through time can quantitatively explain some regional aspects of the reconstructions, the model-data agreement remains imperfect, and differences between reconstructions also hinders the evaluation. Moreover, model-dependency in the response of several feedbacks, particularly sea-ice, but potentially also clouds, means that it is difficult to uniquely attribute Holocene temperature evolution to specific factors. Future work should aim to derive a consensus-signal including uncertainties from the available proxy data which could be used to fingerprint simulations covering a range of plausible feedback strengths.
   Holocene, forcings and feedbacks

5. [Rasmussen et al. 2023] A unique, high-resolution, hydroclimate reanalysis, 40-plus-year (October 1979–September 2021), 4 km (named as CONUS404), has been created using the Weather Research and Forecasting Model by dynamically downscaling of the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis of the global climate dataset (ERA5) over the conterminous United States. The paper describes the approach for generating the dataset, provides an initial evaluation, including biases, and indicates how interested users can access the data. The motivation for creating this National Center for Atmospheric Research (NCAR)–U.S. Geological Survey (USGS) collaborative dataset is to provide research and end-user communities with a high-resolution, self-consistent, long-term, continental-scale hydroclimate dataset appropriate for forcing hydrological models and conducting hydroclimate scientific analyses over the conterminous United States. The data are archived and accessible on the USGS Black Pearl tape system and on the NCAR supercomputer Campaign storage system.
   Downscaling, convection permiting, reanalysis

6. [Schug et al. 2023] Climate change is an indisputable threat to human health, especially for societies already confronted with rising social inequality, political and economic uncertainty, and a cascade of concurrent environmental challenges. Archaeological data about past climate and environment provide an important source of evidence about the potential challenges humans face and the long-term outcomes of alternative short-term adaptive strategies. Evidence from well-dated archaeological human skeletons and mummified remains speaks directly to patterns of human health over time through changing circumstances. Here, we describe variation in human epidemiological patterns in the context of past rapid climate change (RCC) events and other periods of past environmental change. Case studies confirm that human communities responded to environmental changes in diverse ways depending on historical, sociocultural, and biological contingencies. Certain factors, such as social inequality and disproportionate access to resources in large, complex societies may influence the probability of major sociopolitical disruptions and reorganizations—commonly known as “collapse.” This survey of Holocene human–environmental relations demonstrates how flexibility, variation, and maintenance of Indigenous knowledge can be mitigating factors in the face of environmental challenges. Although contemporary climate change is more rapid and of greater magnitude than the RCC events and other environmental changes we discuss here, these lessons from the past provide clarity about potential priorities for equitable, sustainable development and the constraints of modernity we must address
   Climate adaptation, vulnerability, health, holocene

7. [von Storch 2023] Abstract. Forages,the topic of climate –in the sense of “usualweather” –has in the western tradition attracted attention as a possible explanatory factor for differences in societies and in human behavior. Climate, and its purported impact on society, is an integrated element in western thinking and perception. In this essay, the history of ideas about the climatic impact on humans and society and the emergence of the ideology of climatic determinism are sketched from the viewpoint of a natural scientist. This ideology favored the perception of westerners being superior to the people in the rest of the world, giving legitimacy to colonialism. In modern times, when natural sciences instituted self-critical processes (repeatability, falsification) and norms (such as the Mertonian norms named CUDOS), the traditional host for climate issues, namely, geography, lost its grip, and physics took over. This “scientification” of climate science led to a more systematic, critical and rigorous approach of building and testing hypotheses and concepts. This gain in methodical rigor, however, went along with the loss of understanding that climate is hardly a key explanatory factor for societal differences and developments. Consequently, large segments of the field tacitly and unknowingly began reviving the abandoned concept of climatic determinism. Climate science finds itself in a “post-normal” condition, which leads to a frequent dominance of political utility over methodical rigor.
   Climate change science, postnormal

8. [Lin et al. 2023] Abstract. Hasselmann’s theory elucidates how short-term random noise leads to longer-term unpro- voked variations, i.e., red spectra. Here, we study ensembles of numerical model simulations of the hydrodynamics of the Bohai and Yellow Sea concerning internal variability formation. Short(/long) term variations are associated with small(/large) spatial scales, and the internal variability of long-term temporal and large-scale variations is markedly enhanced, even without external forcing on these scales, when the tides are turned off. This pattern is well explained by Hasselmann’s theory. A critical element in this theory is the concept of memory, which in our ensembles exhibits a scale dependence that aligns with the scale-dependent nature of redness. Additionally, this framework clarifies why there is a significant reduction of long-term fluctuations during winter and when tides are active: the system’s memory is notably diminished under these conditions.
   Internal variability and noise, Hasselmann SCM