This study examines the relationships between the diurnal precipitation cycle, local morning insolation, and local and large-scale moisture availability using local radiative flux and precipitation observations from three forested tropical sites, together with ERA5 reanalysis data. Our results suggest that, away from the coast, there is a weak positive correlation between local morning insolation and the magnitude of the afternoon precipitation peak, and a weak negative relationship between locally observed surface moisture in the morning and the magnitude of the afternoon precipitation peak. There is little relationship between large-scale column moisture and the local afternoon precipitation peak. We examine analogous results in convection-permitting simulations. Results suggest that the simulated afternoon precipitation rate shows almost no dependence on surface radiative forcing or moisture availability, while the observed afternoon precipitation rate is dominated by radiative forcing. Simulated and observed satellite precipitation and cloud estimates for a single case study suggest a diversity of surface-flux–precipitation relationships amongst model configurations.

Masters degrees that offer a broad understanding of environmental issues have been taught in universities since the 1960s. As the problems, they address have increased in severity and become global in scale and reach, higher education offerings have flourished accordingly. Today, environmental Masters degrees offer a variety of specializations, are often embedded within university environmental institutes or centers, and they lead thousands of students into environmental careers, as activists, advocates, policymakers, technicians, resource managers, and researchers. They provide an opportunity to understand and critically debate mainstream concepts, like sustainability, the green economy, ecological resilience, environmental services, and good governance. The severity of environmental crises also requires a more radical curriculum: critiques of economic growth (including green growth), social and environmental justice, and the political ecology of unequal access to resources. In light of these complex demands and growing opportunities for environmental programs to address social and environmental justice, we discuss a unique and successful model for interdisciplinary environmental Masters teaching at a large Australian university that has juggled promotion of justice in its program along with meeting financial targets imposed by the neoliberal regime prevalent in Australia's underfunded higher education sector. The program has a distinctive approach to interdisciplinary learning, permitting a very wide range of student choice, and unified teaching efforts across ten Faculties. This has required agile administration, and strong defense of an unusual approach to the management of environmental pedagogy. The Master of Environment program illustrates how taught postgraduate programs can offer an alternative space for personal, institutional and environmental commitment to social and environmental justice.

The Parties to the UNFCCC and Paris Agreement agreed to act on the basis of equity to protect the climate system. Equitable effort sharing is an irreducibly normative matter, yet some influential studies have sought to create quantitative indicators of equitable effort that claim to be value-neutral (despite evident biases). Many of these studies fail to clarify the ethical principles underlying their indicators, some mislabel approaches that favour wealthy nations as ‘equity approaches’ and some combine contradictory indicators into composites we call derivative benchmarks. This Perspective reviews influential climate effort-sharing assessments and presents guidelines for developing and adjudicating policy-relevant (but not ethically neutral) equity research.

Integrated assessment models are often used to evaluate the role of different technologies in meeting global climate goals. Such models have been criticised for failing to address the deep uncertainties and plurality of values that are fundamental to energy transitions. One consequence is that model scenarios overwhelmingly depend on large-scale carbon dioxide removal to hold warming to below 2 °C. Here we propose an alternative approach using Scenario-Focused Decision Analysis (SFDA) as methods that embrace decision making under deep uncertainty. SFDA can accommodate a range of value sets and perspectives, and most importantly can integrate value-based decision-making in designing climate policy. We specifically consider Robust Decision Making (RDM) as an exemplar of SFDA for developing climate policy. We outline an iterative five-stage framework for RDM using the role of carbon dioxide removal in long-term mitigation pathways as an example. The five steps comprise (i) participatory definition of goals, values, potential policy options and uncertainties; (ii) modelling the performance of policy portfolios across a wide range of future scenarios; (iii) visualisation and identification of portfolio vulnerabilities; (iv) analysis of trade-offs; and (v) development of policy strategies. SFDA, and specifically RDM, provide untapped opportunities for diverse actors to explore alternative mitigation pathways and evaluate the robustness of climate policy choices through “deliberation with analysis”. In relation to carbon dioxide removal methods, RDM provides a framework for evaluating their potential for safely meeting climate goals in a societally acceptable manner.

Inequalities are ubiquitous in every society on Earth, and the COVID-2019 pandemic has exposed the marginalized communities that suffer the most. A warming planet will only magnify this gap. On the eve of the 26th session of the Conference of the Parties to the UNFCCC, this Voices asks: how can science inform and address inequalities?

A fully cored sequence of Hesse Clay, Port Campbell Limestone and uppermost Gellibrand Marl in the onshore Otway Basin, southeastern Australia, offers new insight into the evolution of the middle Miocene Port Campbell Limestone. The Port Campbell Limestone comprises grey unconsolidated to semi-consolidated and rarely lithified bioclastic muddy carbonate sands in a stack of thin repetitive cycles within cycles of predominantly shoaling-upward character. A glauconitic band with a distinctive mollusc–echinoderm–bryozoan fauna provides a distinctive marker interval in the sequence. In mineralogy, the Port Campbell Limestone is predominantly calcite with traces of remnant aragonite in muddier low-permeability sands, and with dolomitic zones in permeable intervals. The small non-carbonate component of the Port Campbell Limestone is between 3 and 15 wt% and comprises quartz silt with minor clay, feldspar and mica. Dissolution overprints are prominent throughout the carbonate sequence. Three distinct geochemical signatures of provenance are evident in the Port Campbell Limestone sequence, including possible volcanogenic contributions with felsic sources. Foraminifera are common and generally well preserved. Foraminiferal data suggest a depositional transition from outer shelf conditions in the Gellibrand Marl at ca 15 Ma to middle shelf environments in the lower part of the Port Campbell Limestone during the Middle Miocene Climatic Optimum (MMCO) at ca 14.24 Ma. Shallowing after 14 Ma indicates variable paleodepths of <70 m during and following the end of the Middle Miocene Climatic Transition (MMCT) at ca 13.2 Ma when the sequence was emergent for a brief but undetermined period, corresponding with sharp changes in geochemical ratios. Observed cyclicity in these mid-shelfal, cold-water carbonates is strongly correlated with orbital forcings—eccentricity and obliquity. Sedimentation rates determined from cyclostratigraphic analysis indicate 4–6 cm/kyr at the end of the MMCO, diminishing to 1.5–3 cm/kyr during the MMCT and the subsequent accumulation of the Port Campbell Limestone.

Irrigated agriculture faces significant challenges under climate change, and may not be feasible in parts of the Murray–Darling Basin beyond 2050. Recent research into the cultural politics of water has paid limited attention to the water cultures and relations of irrigators in Minority World countries. We analyse the water relations of grape farm irrigators in the Sunraysia region of Victoria, using interviews and farm tours undertaken between 2014 and 2016. Findings are summarised under five themes: (1) the sociality of irrigation water, (2) temporal and spatial relations, (3) the risk of rain, (4) the micro-scale of water knowledge, and (5) environment as actor. These themes shed light on the diverse relations that constitute both environmental and irrigation water. Irrigators are embedded in these relations at multiple scales, local and distant, mediated by technology and infrastructure. The scale of our focus makes visible water and other environmental knowledge that often goes unnoticed in broader debates over irrigation. The concept of “the environment”, understood as an embodied actor in policy discourse and by irrigators, is an emergent trend that warrants ongoing research attention.

Aim To assess whether climate directly influences aquatic ecosystem dynamics in the temperate landscape of Tasmania or whether the effects of long‐term climatic change are mediated through the terrestrial environment (indirect climate influence). Location Paddy's Lake is located at 1065 m a.s.l. in temperate north‐west Tasmania, a continental island south‐east of mainland Australia (41°15–43°25′ S; 145°00–148°15′ E). Methods We developed a new 13,400 year (13.4 kyr) palaeoecological dataset of lake sediment subfossil cladocerans (aquatic grazers), bulk organic sediment carbon (C%) and nitrogen (N%) and δ13C and δ15N stable isotopes. Comparison of this new data was made with a recently published pollen, geochemistry and charcoal records from Paddy's Lake. Results Low cladoceran diversity at Paddy's Lake is consistent with other temperate Southern Hemisphere lakes. The bulk sediment δ15N values demonstrate a significant lagged negative response to pollen accumulation rate (pollen AR). Compositional shifts of dominant cladoceran taxa (Bosmina meridionalis and Alona guttata) occur following changes in both pollen AR and pollen (vegetation) composition throughout the 13.4 kyr record at Paddy's Lake. The δ15N values demonstrate a significant positive lagged relationship to the oligotrophic:eutrophic cladoceran ratio. Main conclusions Long‐term changes in cladoceran composition lag changes in both pollen AR and terrestrial vegetation composition. We interpret pollen AR as reflecting climate‐driven changes in terrestrial vegetation productivity and conclude that climate‐driven shifts in vegetation are the principal driver of the cladoceran community during the last ca. 13.4 kyr. The significant negative lagged relationship between pollen AR and δ15N reflects the primary control of vegetation productivity over within‐lake nutrient status. Thus, we conclude that the effects of long‐term climate change on aquatic ecosystem dynamics at our site are indirect and mediated by the terrestrial environment. Vegetation productivity controls organic soil development and has a direct influence over lake trophic status via changes in the delivery of terrestrial organic matter into the lake.

Submarine landslides, including the basal shear surfaces along which they fail, and their subsequent infill, are commonly observed in modern seabed and seismic reflection data sets; their resultant relief impacts sediment routing and storage patterns on continental margins. Here, three stacked submarine landslides are documented from the Permian Ecca Group, Laingsburg depocentre, Karoo Basin, South Africa, including two superimposed lateral margins. The stratigraphic framework includes measured sections and correlated surfaces along a 3 km long, 150 m high outcrop. Two stacked 2·0 to 4·5 km wide and 90 m and 60 m deep erosion surfaces are recognized, with lateral gradients of 8° and 4°, respectively. The aim of this study was to understand the evolution of a submarine landslide complex, including: evolution of basal shear surfaces/zones; variation of infill confinement; and location of the submarine landslides in the context of basin-scale sedimentation and degradation rates. Three stages of formation are identified: (i) failure of submarine landslide 1, with deposition of unconfined remobilized deposits; (ii) failure of submarine landslide 2, forming basal shear surface/zone 1, with infill of remobilized deposits and weakly confined turbidites; and (iii) failure of submarine landslide 3, forming basal shear surface/zone 2, with infill of remobilized deposits and confined turbidites, transitioning stratigraphically to unconfined deposits. The expression of basal shear varies laterally, from metres thick zones in silt-rich strata to sharp stepped surfaces in sand-rich strata. Faulting and rotation of overlying bedding suggest that the shear surfaces/zones were dynamic. Stacking of landslides resulted from multi-phase slope failure, increasing down-dip topography and confinement of infilling deposits. The failure slope was probably a low supply tilted basin margin evidenced by megaclast entrainment from underlying basin-floor successions and the lack of channel systems. This study develops a generic model of landslide infill, as a function of sedimentation and degradation rates, which can be applied globally.

AIM: To evaluate the biomization technique for reconstructing past vegetation in the Eastern Mediterraneanâ Black Seaâ Caspianâ Corridor using an extensive modern pollen data set and comparing reconstructions to potential vegetation and observed land cover data. LOCATION: The region between 28â 48°N and 22â 62°E. METHODS: We apply the biomization technique to 1,387 modern pollen samples, representing 1,107 entities, to reconstruct the distribution of 13 broad vegetation categories (biomes). We assess the results using estimates of potential natural vegetation from the European Vegetation Map and the Physicoâ Geographic Atlas of the World. We test whether anthropogenic disturbance affects reconstruction quality using land use information from the Global Land Cover data set. RESULTS: The biomization scheme successfully predicts the broadscale patterns of vegetation across the region, including changes with elevation. The technique discriminates deserts from shrublands, the prevalence of woodlands in moister lowland sites, and the presence of temperate and mixed forests at higher elevations. Quantitative assessment of the reconstructions is less satisfactory: the biome is predicted correctly at 44% of the sites in Europe and 33% of the sites overall. The low success rate is not a reflection of anthropogenic impacts: only 33% of the samples are correctly assigned after the removal of sites in anthropogenically altered environments. Open vegetation is less successfully predicted (33%) than forest types (73%), reflecting the underâ representation of herbaceous taxa in pollen assemblages and the impact of longâ distance pollen transport into open environments. Samples from small basins (<1 km²) are more likely to be reconstructed accurately, with 58% of the sites in Europe and 66% of all sites correctly predicted, probably because they sample an appropriate pollen source area to reflect regional vegetation patterns in relatively heterogeneous landscapes. While methodological biases exist, the low confidence of the quantitative comparisons should not be overâ emphasized because the target maps themselves are not accurate representations of vegetation patterns in this region. MAIN CONCLUSIONS: The biomization scheme yields reasonable reconstructions of the broadscale vegetation patterns in the Eastern Mediterraneanâ Black Seaâ Caspianâ Corridor, particularly if appropriateâ sized sampling sites are used. Our results indicate biomization could be used to reconstruct changing patterns of vegetation in response to past climate changes in this region.

The sandstone peak-forest landscape in Zhangjiajie UNESCO Global Geopark of Hunan Province, China, is characterized by >3000 vertical pillars and peak walls of up to 350 m height, representing a spectacular example of sandstone landform variety. Few studies have addressed the mechanisms and timescales of the longer-term evolution of this landscape, and have focused on fluvial incision. We use in situ cosmogenic nuclides combined with GIS analysis to investigate the erosional processes contributing to the formation of pillars and peak-forests, and discuss their relative roles in the formation and decay of the landscape. Model maximum-limiting bedrock erosion rates are the highest along the narrow fluvial channels and valleys at the base of the sandstone pillars (~83–122 mm kyr−1), and lowest on the peak wall tops (~2.5 mm kyr−1). Erosion rates are highly variable and intermediate along vertical sandstone peak walls and pillars (~30 to 84 mm kyr−1). Catchment-wide denudation rates from river sediment vary between ~26 and 96 mm kyr−1 and are generally consistent with vertical wall retreat rates. This highlights the importance of wall retreat for overall erosion in the sandstone peak-forest. In combination with GIS-derived erosional volumes, our results suggest that the peak-forest formation in Zhangjiajie commenced in the Pliocene, and that the general evolution of the landscape followed our sequential refined model: (i) slow lowering rates following initial uplift; (ii) fast plateau dissection by headward knickpoint propagation along joints and faults followed by; (iii) increasing contribution of wall retreat in the well-developed pillars and peak-forests and a gradual decrease in overall denudation rates, leading to; (iv) the final consumption of pillars and peak-forests. Our study provides an approach for quantifying the complex interplay between multiple geomorphic processes as required to assess the evolutionary pathways of other sandstone peak-forest landscapes across the globe.

This paper discusses the concept of potential natural vegetation (PNV) in the light of the pollen records available to date for the Macaronesian biogeographical region, with emphasis on the Azores Islands. The classical debate on the convenience or not of the PNV concept has been recently revived in the Canary Islands, where pollen records of pre‐anthropic vegetation seemed to strongly disagree with the existing PNV reconstructions. Contrastingly, more recent PNV model outputs from the Azores Islands show outstanding parallelisms with pre‐anthropic pollen records, at least in qualitative terms. We suggest the development of more detailed quantitative studies to compare these methodologies as an opportunity for improving the performance of both. PNV modelling may benefit by incorporating empirical data on past vegetation useful for calibration and validation purposes, whereas palynology may improve past reconstructions by minimizing interpretative biases linked to differential pollen production, dispersal and preservation.