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The ‘4 per mille Soils for Food Security and Climate’ was launched at the COP21 with an aspiration to increase global soil organic matter stocks by 4 per 1000 (or 0.4 %) per year as a compensation for the global emissions of greenhouse gases by anthropogenic sources. This paper surveyed the soil organic carbon (SOC) stock estimates and sequestration potentials from 20 regions in the world (New Zealand, Chile, South Africa, Australia, Tanzania, Indonesia, Kenya, Nigeria, India, China Taiwan, South Korea, China Mainland, United States of America, France, Canada, Belgium, England & Wales, Ireland, Scotland, and Russia). We asked whether the 4 per mille initiative is feasible for the region. The outcomes highlight region specific efforts and scopes for soil carbon sequestration. Reported soil C sequestration rates globally show that under best management practices, 4 per mille or even higher sequestration rates can be accomplished. High C sequestration rates (up to 10 per mille) can be achieved for soils with low initial SOC stock (topsoil less than 30 t C ha− 1), and at the first twenty years after implementation of best management practices. In addition, areas which have reached equilibrium will not be able to further increase their sequestration. We found that most studies on SOC sequestration only consider topsoil (up to 0.3 m depth), as it is considered to be most affected by management techniques. The 4 per mille number was based on a blanket calculation of the whole global soil profile C stock, however the potential to increase SOC is mostly on managed agricultural lands. If we consider 4 per mille in the top 1m of global agricultural soils, SOC sequestration is between 2-3 Gt C year− 1, which effectively offset 20–35% of global anthropogenic greenhouse gas emissions. As a strategy for climate change mitigation, soil carbon sequestration buys time over the next ten to twenty years while other effective sequestration and low carbon technologies become viable. The challenge for cropping farmers is to find disruptive technologies that will further improve soil condition and deliver increased soil carbon. Progress in 4 per mille requires collaboration and communication between scientists, farmers, policy makers, and marketeers.

Heatwaves have potential health and safety implications for many workers, and heatwaves are predicted to increase in frequency and intensity with climate change. There is currently a lack of comparative evidence for the effects of heatwaves on workers' health and safety in different climates (sub-tropical and temperate). This study examined the relationship between heatwave severity (as defined by the Excess Heat Factor) and workers' compensation claims, to define impacts and identify workers at higher risk.Workers' compensation claims data from Australian cities with temperate (Melbourne and Perth) and subtropical (Brisbane) climates for the years 2006-2016 were analysed in relation to heatwave severity categories (low and moderate/high severity) using time-stratified case-crossover models.Consistent impacts of heatwaves were observed in each city with either a protective or null effect during heatwaves of low-intensity while claims increased during moderate/high-severity heatwaves compared with non-heatwave days. The highest effect during moderate/high-severity heatwaves was in Brisbane (RR 1.45, 95% CI: 1.42-1.48). Vulnerable worker subgroups identified across the three cities included: males, workers aged under 34 years, apprentice/trainee workers, labour hire workers, those employed in medium and heavy strength occupations, and workers from outdoor and indoor industrial sectors.These findings show that work-related injuries and illnesses increase during moderate/high-severity heatwaves in both sub-tropical and temperate climates. Heatwave forecasts should signal the need for heightened heat awareness and preventive measures to minimise the risks to workers.

AbstractCrustose coralline algae (CCA) are a group of calcifying red macroalgae crucial to tropical coral reefs because they form crusts that cement together the reef framework1. Previous research into the responses of CCA to ocean warming (OW) and ocean acidification (OA) have found reductions in calcification rates and survival2,3, with magnitude of effect being species-specific. Responses of CCA to OW and OA could be linked to evolutionary divergence time and/or their underlying molecular biology, the role of either being unknown in CCA. Here we showSporolithon durum, a species from an earlier diverged lineage that exhibits low sensitivity to climate stressors, had little change in metabolic performance and did not significantly alter the expression of any genes when exposed to temperature and pH perturbations. In contrast,Porolithon onkodes, a species from a recently diverged lineage, reduced photosynthetic rates and had over 400 significantly differentially expressed genes in response to experimental treatments, with differential regulation of genes relating to physiological processes. We suggest earlier diverged CCA may be resistant to OW and OA conditions predicted for 2100, whereas taxa from more recently diverged lineages with demonstrated high sensitivity to climate stressors may have limited ability for acclimatisation.

Natural ecosystems are threatened by climate change, fragmentation, and non-native species. Dispersal-limitation potentially compounds impacts of these factors on plant diversity, especially in isolated vegetation patches. Changes in climate can impact the phenology of native species in distinct ways from non-natives, potentially resulting in cascading impacts on native communities. Few empirical studies have examined the combined effects of climate change and dispersal limitation on community diversity or phenology. Using a five-year dispersal-restriction experiment in an invaded semi-arid annual plant system in Western Australia, we investigated the interactive effects of dispersal-restriction and inter-annual rainfall variation on community composition, species dominance and seed production timing. We found inter-annual rainfall variation to be the principal driver of community dynamics. Drought years had long-term, stable effects on community composition, with evidence of shifts from native toward non-native dominance. Surprisingly, community composition remained largely unchanged under dispersal restriction. A subtle dispersal rescue effect was evident for a dominant native annual forb and a dominant annual non-native grass but only in average rainfall years. The timing of seed production was primarily driven by annual rainfall with native and non-native grasses having opposite responses. There was no evidence that inter-annual variation in seeding timing affected community diversity over time. Our study demonstrates that dispersal is not a major factor in driving community diversity in this invaded, semi-arid system. Results do suggest, however, that increases in drought frequency likely benefit non-native species over natives in the long term. Climate Change Ecology, 2 ISSN:2666-9005

AbstractWhile perovskite solar cell (PSC) efficiencies are soaring at a laboratory scale, these are most commonly achieved with evaporated gold electrodes, which would present a significant expense in large‐scale production. This can be remedied through the use of significantly cheaper carbon electrodes that, in contrast to metals, also do not migrate through the device. To this end, the present work investigates simple‐to‐prepare aluminum‐supported carbon electrodes derived from commercially available, inexpensive materials that can be applied onto various hole‐transporting materials and enable photovoltaic performances on par with those provided by gold electrodes. Successful integration of the new carbon‐based electrode into flexible devices produced by a roll‐to‐roll printing technology by both pressing and lamination is demonstrated. However, temperature cycling durability tests reveal that the use of carbon electrodes based on commercial pastes is hindered by incompatibility of adhesive additives with the key components of the PSCs under heating. Resolving this issue, tailor‐made graphite electrodes devoid of damaging additives are introduced, which improve the PSC stability under temperature cycling test protocol to the level provided by benchmark gold electrodes. The study highlights current challenges in developing laminated carbon electrodes in PSCs and proposes strategies toward the resolution thereof.