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Soil organic carbon storage is a well-identified climate change mitigation solution. Quantification of the soil carbon storage in cropland for agricultural policy and offset carbon markets using in situ sampling would be excessively costly, especially at the intrafield scale. For this reason, comprehensive monitoring, reporting, and verification (MRV) of soil carbon and its explanatory variables at a large scale need to rely on hybrid approaches that combine remote sensing and modelling tools to provide the carbon budget components with their associated uncertainties at intrafield scale. Here, we present AgriCarbon-EO v1.0.1: an end-to-end processing chain that enables the estimation of carbon budget components for major and cover crops at intrafield resolution (10 m) and regional extents (e.g. 10 000 km 2) by assimilating remote sensing data (e.g. Sentinel-2 and Landsat8) in a physically based radiative transfer (PROSAIL) and agronomic models (SAFYE-CO2). The data assimilation in AgriCarbon-EO is based on a novel Bayesian approach that combines normalized importance sampling and look-up table generation. This approach propagates the uncertainties across the processing chain from the reflectances to the output variables. After a presentation of the chain, we demonstrate the accuracy of the estimates of AgriCarbon-EO through an application over winter wheat in the southwest of France during the cropping seasons from 2017 to 2019. We validate the outputs with flux tower data for net ecosystem exchange, biomass destructive samples, and combined harvester yield maps. Our results show that the scalability and uncertainty estimates proposed by the approach do not hinder the accuracy of the estimates (net ecosystem exchange, NEE: RMSE =1.68 –2.38 gC m -2 , R2=0.87 –0.77; biomass: RMSE =11.34 g m -2 , R2=0.94). We also show the added value of intrafield simulations for the carbon components through scenario testing of pixel and field simulations (biomass: bias =-47 g m -2 , - 39 % variability). Our overall analysis shows satisfying accuracy, but it also points out the need to represent more soil processes and include synthetic aperture radar data that would enable a larger coverage of AgriCarbon-EO. The paper's findings confirm the suitability of the choices made in building AgriCarbon-EO as a hybrid solution for an MRV scheme to diagnose agro-ecosystem carbon fluxes. [ABSTRACT FROM AUTHOR]

Risk can represent an important non-monetary barrier to the adoption of climate change mitigation practices. This paper deals with how risk aversion influences the fertilization behavior of farmers. We analytically show that a decreasing variance of yield along with nitrogen inputs encourages risk averse farmers to apply larger quantities of fertilizers. Data concerning three departments in France are then used to determine (i) crop yield response function to N fertilizer and (ii) farmers' risk aversion behavior on the basis of their current fertilizer applications. We find that risk aversion is associated with an additional application of 29 kg/ha compared with risk neutral behavior, which represents an average loss of €76/ha. We show that the reduction of an abatement linked to risk aversion should appear only when crop yield variance is convex with respect to N fertilizer. Lastly, our results show that an insurance contract that covers yield variability may be an interesting tool to mitigate emissions. [ABSTRACT FROM AUTHOR]

Background: Climate change has been shown to have long-term effects on mental health, yet, to date, there have been few studies on how children and adolescents experience and respond to ecological changes and how and why they engage in climate action. We explored empirically young people's views about climate change and how distinct cultural contexts influence individual climate action. Methods: We invited children and adolescents (ages 7 to 18) and their caregivers from the general population in the United States and France to participate in semi-structured focus groups. We recruited 74 participants, 39 in the U.S. (33 children and adolescents, 6 parents) and 35 in France (32 children and adolescents, 3 parents). Focus groups with participants centered on their emotions, beliefs, and actions around climate change. We analyzed the focus group data and developed themes via grounded theory and symbolic interactionist approaches. Results: Many participants described experiencing anger, hopelessness, guilt, and sadness in response to climate change, and a smaller number endorsed significant anxiety symptoms; many described frustration about needing to fix the mistakes of earlier generations. Younger participants frequently misunderstood the purpose of their parents' eco-conscious behaviors unless they were provided with age-appropriate explanations. Participants described a spectrum of experiences when trying to discuss climate change with peers and family, ranging from genuine support to apathy to hostility. Between the two samples, U.S. participants experienced more conflict with adults about climate change than French participants, but French participants described a greater lack of political agency compared to U.S. participants. Participants in both samples expressed a relatively balanced view of climate action, recognizing the significance of individual actions while acknowledging the limits of their power in the face of systemic issues. Some found hope and empowerment through climate action and building communities around it. Conclusion: Discussing with children and adolescents what adults are doing to mitigate climate change can provide reassurance, model prosocial behaviors, and inspire their own investment in climate action. Adults seeking to support the psychological well-being of young people should both support their concerns and actions around climate change and create avenues for young people to meaningfully engage in climate action. [ABSTRACT FROM AUTHOR]

Building on CMIP6 climate simulations, updated global and regional observations, and recently introduced statistical methods, we provide an updated assessment of past and future warming over France. Following the IPCC AR6 and recent global-scale studies, we combine model results with observations to constrain climate change at the regional scale. Over mainland France, the forced warming in 2020 with respect to 1900–1930 is assessed to be 1.66 [1.41 to 1.90] ∘ C, i.e., in the upper range of the CMIP6 estimates, and is almost entirely human-induced. A refined view of the seasonality of this past warming is provided through updated daily climate normals. Projected warming in response to an intermediate emission scenario is assessed to be 3.8 ∘ C (2.9 to 4.8 ∘ C) in 2100 and rises up to 6.7 [5.2 to 8.2] ∘ C in a very high emission scenario, i.e., substantially higher than in previous ensembles of global and regional simulations. Winter warming and summer warming are expected to be about 15 % lower than and 30 % higher than the annual mean warming, respectively, for all scenarios and time periods. This work highlights the importance of combining various lines of evidence, including model and observed data, to deliver the most reliable climate information. This refined regional assessment can feed adaptation planning for a range of activities and provides additional rationale for urgent climate action. Code is made available to facilitate replication over other areas or political entities. [ABSTRACT FROM AUTHOR]

Under the influence of climate change, wildfire regimes are expected to intensify and expand to new areas, increasing threats to natural and socioeconomic assets. We explore the environmental and economic implications for the forest sector of climate‐induced changes in wildfire regimes. To retain genericity while considering local determinants, we focus on the regional level and take Mediterranean France as an example. Coupling a bioeconomic forest sector model and a model of wildfire activity, we perform spatially explicit simulations under various levels of radiative forcing. By using a probabilistic framework, we also assess the propagation of several sources of uncertainty to the forest sector, considering both climate‐induced uncertainty and the intrinsic stochasticity of the fire process. By the end of the century, summer burned areas increase by up to 55%, causing moderate losses of merchantable timber and forest carbon stocks, with cascading impacts for industrial activities and climate mitigation in the forest sector. Implications for industries remain limited, but we observe price increases, especially for softwoods, as well as spatially differentiated changes in producer welfare. Inter‐annual fluctuations explain most of uncertainty in wildfire activity, but their impacts on the forest sector are quickly dampened. Over time, owing to the cumulative nature of wildfire impacts on forest resources, uncertainty related to climate warming, climate models' response and stochasticity intrinsic to the wildfire phenomenon strongly increase in relative importance. Results reassert the need to consider multiple futures in prospective assessments, including uncertainty inherent to natural processes, often omitted in large‐scale economic assessments. Plain Language Summary: Forest fires in the Mediterranean are expected to become more numerous, more intense, and to reach new areas due to climate change. Forest resources, carbon sequestrated in forests, as well as economic activities related to forestry, are threatened by this evolution. This article focuses on Southern France and uses large‐scale model simulations to explore these dynamics. We show that burned areas in forests may increase by more than half by 2100, leading to a decrease in forest resources (timber) by up to 5%. Besides, prices for wood products may increase, especially for softwoods, with implications for the welfare of timber producers and consumers. Moreover, these results are heterogenous across space, and areas to the south and to the west are more gravely affected. However, these trends come with relatively large uncertainties. We show that uncertainties concerning the evolution of forest fires themselves are largely due to annual variability in weather conditions. On the contrary, uncertainties concerning economic activity in forestry are mostly due to the unknown future evolution of greenhouse gas emissions and to differences in climate models functioning. Our results reassert the need to consider several possible sources of uncertainty in long‐term prospective assessments. Key Points: Models project an intensification of wildfire regimes in southern France, losses of forest resources and carbon, disturbances to forestryUncertainty in projections is dominated by annual fluctuations for wildfire activity, by choice of climate model/scenario for forestryProspective bioeconomic assessments need to consider multiple possible futures but also stochasticity intrinsic to disturbance processes [ABSTRACT FROM AUTHOR]

We present a local-scale atmospheric inversion framework to estimate the location and rate of methane (CH 4) and carbon dioxide (CO 2) releases from point sources. It relies on mobile near-ground atmospheric CH 4 and CO 2 mole fraction measurements across the corresponding atmospheric plumes downwind of these sources, on high-frequency meteorological measurements, and on a Gaussian plume dispersion model. The framework exploits the scatter of the positions of the individual plume cross sections, the integrals of the gas mole fractions above the background within these plume cross sections, and the variations of these integrals from one cross section to the other to infer the position and rate of the releases. It has been developed and applied to provide estimates of brief controlled CH 4 and CO 2 point source releases during a 1-week campaign in October 2018 at the TOTAL experimental platform TADI in Lacq, France. These releases typically lasted 4 to 8 min and covered a wide range of rates (0.3 to 200 g CH 4 /s and 0.2 to 150 g CO 2 /s) to test the capability of atmospheric monitoring systems to react fast to emergency situations in industrial facilities. It also allowed testing of their capability to provide precise emission estimates for the application of climate change mitigation strategies. However, the low and highly varying wind conditions during the releases added difficulties to the challenge of characterizing the atmospheric transport over the very short duration of the releases. We present our series of CH 4 and CO 2 mole fraction measurements using instruments on board a car that drove along roads ∼50 to 150 m downwind of the 40 m × 60 m area for controlled releases along with the estimates of the release locations and rates. The comparisons of these results to the actual position and rate of the controlled releases indicate ∼10 %–40 % average errors (depending on the inversion configuration or on the series of tests) in the estimates of the release rates and ∼30 –40 m errors in the estimates of the release locations. These results are shown to be promising, especially since better results could be expected for longer releases and under meteorological conditions more favorable to local-scale dispersion modeling. However, the analysis also highlights the need for methodological improvements to increase the skill for estimating the source locations. [ABSTRACT FROM AUTHOR]

We present a local-scale atmospheric inversion framework to estimate the location and rate of methane (CH4) and carbon dioxide (CO2) releases from point sources. It relies on mobile near-ground atmospheric CH4 and CO2 mole fraction measurements across the corresponding atmospheric plumes downwind the sources, on high-frequency meteorological measurements, and a Gaussian plume dispersion model. It exploits the spread of the positions of individual plume cross-sections and the integrals of the gas mole fractions above the background within these plume cross-sections to infer the position and rate of the releases. It has been developed and applied to provide estimates of brief controlled CH4 and CO2 point source releases during a one-week campaign in October 2018 at the TOTAL's experimental platform TADI in Lacq, France. These releases lasted typically 4 to 8 minutes and covered a wide range of rates (0.3 to 200 gCH4/s and 0.2 to 150 gCO2/s) to test the capability of atmospheric monitoring systems to react fast to emergency situations in industrial facilities. It also allowed testing their capability to provide precise emission estimates for the application of climate change mitigation strategies. However, the low and highly varying wind conditions during the releases added difficulties to the challenge of characterizing the atmospheric transport over the very short duration of the releases. We present our series of measurements of CH4 and CO2 mole fractions using instruments onboard a car that drives along the roads ~50 to 150 m downwind the 40 m x 60 m area of controlled releases for each of the releases and the results from the inversions of the release locations and rates. The comparisons of these results to the actual position and rate of the controlled release indicate a 20 %-30 % average error on the release rates and a ~30-40 m errors in the estimates of the release locations. These results are shown to be promising especially since better results could be expected for longer releases and under meteorological conditions more favorable to local scale dispersion modeling. [ABSTRACT FROM AUTHOR]

Highlights • Coupling economic and biogenic carbon models to assesses energy policy scenarios. • Complete GHG life cycle inventories of the French transport sub-sector are built. • Dynamic approach is needed for transport GHG emissions and impact determinations. • The mitigation is 462% higher than the static assumption for 2G bioethanol. • The model is sensitive to forest rotation length, robust to tree growth parameters. Abstract Bioenergy systems are promoted in an effort to mitigate climate change, and policies are defined accordingly to be implemented in the coming decades. Life Cycle Assessment (LCA) is used to assess the environmental performance of bioenergy systems, yet subject to the limitations of static approaches. In classical LCA, no temporal differentiation is undertaken: all inventoried instant to long-term greenhouse gases emissions (GHG) are aggregated and characterised in the same way, over a fixed time horizon, by means of fixed characterisation factors. Positive and negative impact contributions of dynamic biogenic carbon (C bio) sum up to zero, yielding the same result as carbon neutral estimates. Climate mitigation results are biased without the temporal consideration of these flows. The purpose of the study is to highlight the time-sensitive potential climatic consequences of policy-driven transport strategies for metropolitan France, in the specific context of the dynamic LCA framework and climate change mitigation. We therefore propose a dynamic approach coupling a partial-equilibrium model (PEM) with dynamic C bio models. The PEM analyses in detail the techno-economic performance of the metropolitan French energy-transport sector. It explores prospective optimization options (supply-demand equilibrium) of emerging commodity and energy process pathways in response to a policy in question. The C bio model generates dynamic inventories of the C bio embedded in the primary renewable biomass outputs of the PEM. It captures the dynamic C bio exchange flows between the atmosphere and the technosphere over time: negative emissions from fixation (sequestration) and positive emissions from release (e.g. combustion or decay). A dynamic impact method is applied to evaluate the mitigation effects of C bio from forest wood residues by comparing the climate change impacts from complete carbon (fossil + biogenic) with carbon neutral inventories across scenarios. Two sets of results are computed concerning the overall transport (all emissions) and bioethanol (wood-to-fuel emissions) systems. The mitigation effect from long-term historic sequestration allocated to bioethanol (462%) is significantly larger than for transport (3%), expressed as the difference with carbon neutral estimates. The fossil-sourced emissions from bioethanol production represents only 5.4%. In contrast, a comparison with an alternative reference scenario involving wood decay demonstrated higher impacts (i.e. an increase of 316%) than carbon neutral estimates. The representation of the actual climatic consequences depends on the chosen fixed end-year of the dynamic impact assessment. Moreover, the mitigation effect is proven sensitive to the rotation length of forestry wood: the shorter the length the lower the mitigation from using renewable forest resources. Other energy-policy scenarios, C bio modelling approaches and consequences of indirect effects should be further studied and contrasted. [ABSTRACT FROM AUTHOR]

• Local authorities are key in coastal territories' adaptation to climate change. • Interviews cover 29 French Mediterranean municipalities. • Beaches and residential economy ground the social representation of the territory. • Coastal risks are given little consideration, except for beach erosion. • Territorial inertia, i.e. keeping the same territorial trajectory, impedes adaptation. Adaptation to climate change is a critical issue in coastal areas, at risk from sea-level rise, erosion, and sea flooding. In territories strongly urbanized and long oriented toward tourism and a residential economy, a change in coastal management and territorial development is hard to initiate. In Provence-Alpes-Côte d'Azur (France), a leading tourism region, this article explores how local authorities perceive climate change and talk about adaptation strategies. Interviews with municipal-level authorities, both elected officials and technical agents, reveal the influence of territorial inertia, with persistent statements promoting the beach- and residential-oriented economy and a wait-and-see attitude regarding climate change. Beach erosion is the only coastal risk interviewees really recognize, while sea-level rise and sea flooding are barely perceived. Yet evidence supporting the possibility of a future change in position is provided by the younger generation of interviewees, who are more aware of environmental challenges. Providing original data for a coastal region often considered as a model of development throughout the world, this article also proposes an original and transferable method combining geographical sampling of municipalities, text statistics and qualitative analysis of interviews, to apprehend the social representations of the coast, of climate change and coastal risks. Such a methodology is recommended prior to any quantitative assessment of climate action at local scale. [ABSTRACT FROM AUTHOR]

Bioeconomy addresses the triple balancing challenge posed by the Paris Agreement: inducing additional GHG mitigation alongside biophysical carbon dioxide removals, while keeping fossil carbon in the ground. The use of woody plants as construction materials could simultaneously address this challenge: CO 2 is absorbed through photosynthesis, while wood-based products provide mitigation by replacing either petrochemical materials such as plastic boards or energy-intensive materials like bricks. This study combines, at the scale of France, static and dynamic life cycle assessment with soil carbon simulations to investigate the long-term environmental performance of using, as input for the building sector, black locust (Robinia pseudoacacia L.) planted on "carbon vulnerable lands". These are areas specifically selected for their low soil organic carbon (SOC) levels and low potential to interfere with food security. After the consecutive cultivation of three rotations, black locust was shown to stock an additional 92000 kg ha−1 of carbon in soils as SOC. The mitigation effect from the plastic board replacement is the major contributor to the assessed environmental impacts, including climate change, leading the black locust system to generally perform better than the reference system where the carbon vulnerable areas are left as they are with their initial vegetation. Considering that cultivation starts in 2022, the dynamic evaluation of the global mean temperature change (GMTC) shows that the black locust system results in net negative emissions in the near- and mid-term, but with a GMTC overshot in the second half of the century. Even if a considerable carbon stock is created through time (e.g., 81% and 39% of the carbon captured by photosynthesis, in 2050 and 2100 respectively), the GHG emissions stemming from manufacturing and end-of-life processes were shown to offset the benefit of carbon capture. [Display omitted] • Black locust plantation and utilization in buildings induce negative emissions. • Black locust system yields greater climate benefits than the initial vegetation. • Plastic board replacement explains the superior performance for 13/16 impacts. • By 2136, the largest temperature reduction of 3.9E-09 K per ha is simulated. • 15% of the carbon captured by 3 rotations is still stocked after 260 years. [ABSTRACT FROM AUTHOR]

Biochar is increasingly considered an efficient amendment to improve soil fertility and store carbon in soils for climate change mitigation. However, few field studies have evaluated biochar impacts on soil fauna and especially earthworms in temperate areas despite their importance for soil structure and laboratory-based evidence of potential adverse effects. We investigated the effects of three biochars (from rapeseed, miscanthus and compost reject) in mixture with a green waste compost on the abundance and composition of earthworm communities during a three-year field experiment in northern France. Compost alone or biochar-compost mixtures were applied at 11.7 t dry matter ha−1 and compared to equivalent mineral fertilization. Biochar-compost mixtures did not affect total earthworm density and biomass, while contrasting effects concerning specific ecological groups were observed. Compost addition increased juvenile endogeic earthworm density roughly one month after amendment while no adverse short-term effects of biochar-compost mixtures were observed. Two years after amendment application, anecic earthworm density was higher for the mixture with compost and biochar from compost rejects, which also resulted in the highest soil organic carbon concentrations. We conclude that biochar-compost mixtures at low but more economically viable biochar application rates could be used as an increasingly understood beneficial soil amendment under temperate climate conditions without adverse effects on earthworm communities. [ABSTRACT FROM AUTHOR]

Following the Paris agreement in 2015, the European Union (EU) set a carbon neutrality objective by 2050, and so did France. The French agricultural sector can contribute as a carbon sink through carbon storage in biomass and soil, in addition to reducing GHG emissions. The objective of this study is to quantitatively assess the additional storage potential and cost of a set of eight carbon-storing practices. The impacts of these agricultural practices on soil organic carbon storage and crop production are assessed at a very fine spatial scale, using crop and grassland models. The associated area base, GHG budget, and implementation costs are assessed and aggregated at the region level. The economic model BANCO uses this information to derive the marginal abatement cost curve for France and identify the combination of carbon storing practices that minimizes the total cost of achieving a given national net GHG mitigation target. We find that a substantial amount of carbon, 36.2 to 52.9 MtCO 2 e yr−1, can be stored in soil and biomass for reasonable carbon prices of 55 and 250 € tCO 2 e−1, respectively (corresponding to current and 2030 French carbon value for climate action), mainly by developing agroforestry and hedges, generalising cover crops, and introducing or extending temporary grasslands in crop sequences. This finding questions the 3–5 times lower target of 10 MtCO2e.yr−1 retained for the agricultural carbon sink by the French climate neutrality strategy. Overall, this would decrease total French GHG emissions by 9.2–13.8%, respectively (reference year 2019). • Additional carbon storage, net GHG budget, and cost of 8 agricultural practices. • MACC shows abatement potential of 40–60 MtCO 2 e.yr−1 for carbon price 55–250 €.tCO 2 e−1. • Key practices: agroforestry, hedges, cover crops, grasslands in crop sequences. • No "one size fits all strategy" due to heterogeneity across regions and practices. • French agricultural carbon sink potential is 5 times higher than anticipated by the government. [ABSTRACT FROM AUTHOR]

The article offers information on the "Historical Climatology" conference that took place at the German Historical Institute in Paris, France from September 5-6, 2011. Papers presented at the conference discussed topics such as how historians can contribute to finding a solution to climate change, how climate change affected animals in England and Wales during the 14th century, and how certain types of documentary data can aid in the reconstruction of European climates.

• Prior beliefs and demographics affect reading accuracy and knowledge gains from scenarios. • In contrast, effects from different visualization formats analyzed are relatively minor. • Graphs with steep slope are disadvantageous over tables and graphs with gradual slope. • Tailoring formats to demographic and country differences to some extent reduces adverse effects. While scenarios are used extensively for communication about climate change mitigation, little is known about the interpretation of these scenarios by citizens. We conducted a cross-country empirical evaluation of scenario visualizations for global mitigation, using online surveys in Germany (N = 379), Poland (N = 223), and France (N = 225). Each respondent received visualizations of the required changes in global carbon dioxide emissions and composition of electricity supply (fossil fuels, nuclear, and renewable sources) for limiting global warming to 1.5 °C. We evaluated the effects of respondents' demographics, prior beliefs, numeracy, and graph literacy on the reading accuracy and knowledge gains from the visualizations. We also included an experimental between-groups design on visualization format, where four groups received different graph formats (steep or gradual graphs with depictions of uncertainty ranges or scenario ensembles) and the fifth group received a table. Results showed that higher education level, numeracy, and graph literacy increased reading accuracy in all countries, while age reduced them. Respondents with prior beliefs about climate change mitigation that matched the information in the visualizations had also higher reading accuracy and knowledge gains. While the effects of different visualization formats were comparatively minor, customizing formats according to demographic and country differences was used to reduce adverse effects from these differences. These results emphasize the need to design visualizations that match characteristics of the intended audience and could inform better communication of climate change mitigation scenarios to non-expert audience. [ABSTRACT FROM AUTHOR]

[Display omitted] • Growth was negatively related to defoliation in conifers and broadleaves. • Even slightly defoliated trees (15%) showed significant growth reduction. • Overall, growth decreased by 0.7–0.9% per unit increase of defoliation. • Defoliation shifts can point at changes in growth and carbon sequestration. Climate and weather fluctuations and changes are the most important environmental drivers of tree canopy defoliation, an indicator of forest health. We examined the relationship between tree defoliation and Basal Area Increment (BAI), a dimension of tree growth related to wood biomass increment and carbon sequestration and therefore to the climate change mitigation potential of forests. We analysed data from mostly even-aged, single-species permanent monitoring plots in France over two growing periods (1995–2004: 47 plots, 2008 trees; 2000–2009: 63 plots, 3116 trees) and for which precipitation deficit was identified as the main environmental driver of defoliation. Trees from ten different species were assessed annually for defoliation and measured periodically for growth, from which we derived periodical (10-year) BAI (BAI period). We investigated (i) direction and significance of defoliation-BAI period relationships and (ii) occurrence, size and significance of BAI deviation of progressively defoliated trees in proportion to the BAI of undefoliated trees (BAI rel). Analyses were first carried out at the level of individual plots, with results subsequently evaluated using meta-analysis and further aggregated at different levels (all species, functional groups, individual species). BAI period resulted negatively and significantly related to defoliation, with a significant reduction detected already at slight (15%) defoliation level. A generalized statistically significant reduction of BAI rel was obvious, leading to an estimated reduction of 0.7–0.8% per 1% increase in defoliation for conifers and 0.9% for broadleaves. Considering the observed distribution of trees along the defoliation range, our results indicate an overall growth reduction of ca. 42% in comparison to a theoretical population of undefoliated trees. Shifts in such a distribution can result into loss or gain of growth, which in turn may have cascading effects on carbon sequestration and therefore on land-climate interactions. In the context of the significant increase in defoliation observed in Europe in recent decades, our results suggest that even slight and moderate variations in defoliation may have had a significant impact on tree and forest growth. [ABSTRACT FROM AUTHOR]

• Profound future uncertainty is present when planning renewable energy investments. • Many decisions are made at the territorial level, especially related to heating. • Simple decision-making tool allowing consideration of uncertainties is needed. • We seek robust solutions performing well over a wide range of plausible futures. • Current domestic natural gas heating performs badly in all futures simulated. Considerable and fast investments in renewable energy technologies are needed in order to reduce greenhouse gas emissions to achieve the Paris Agreement climate change mitigation targets. Many of these investment decisions are made at the territorial level, especially those related to the heating sector. When choosing the most suitable energy investments, decision makers need to consider several performance indicators—economic, social and environmental—simultaneously. In addition, decision makers face profound uncertainty concerning the future, as decisions on energy systems are always long-term investments. We aim to provide territorial decision makers with a simple decision-making framework that combines a robust decision-making method with multi-criteria analysis and allows the inclusion of territorial features. The main aim is to develope a simple tool that provides data to seek robust solutions which will perform well over a wide range of plausible futures. The method proposed is illustrated with a case study on renewable heating solutions based in France. Heat pumps or central biomass plants are robust in various future conditions, while current domestic natural gas based heating performs badly compared to the renewable technologies. [ABSTRACT FROM AUTHOR]

Introduction of temporary grasslands into cropping cycles could be a sustainable management practice leading to increased soil organic carbon (SOC) to contribute to climate change adaption and mitigation. To investigate the impact of temporary grassland management practices on SOC storage of croplands, we used a spatially resolved sampling approach combined with geostatistical analyses across an agricultural experiment. The experiment included blocks (0.4- to 3-ha blocks) of continuous grassland, continuous cropping and temporary grasslands with different durations and N-fertilizations on a 23-ha site in western France. We measured changes in SOC storage over this 9-year experiment on loamy soil and investigated physicochemical soil parameters. In the soil profiles (0–90 cm), SOC stocks ranged from 82.7 to 98.5 t ha−1 in 2005 and from 81.3 to 103.9 t ha−1 in 2014. On 0.4-ha blocks, the continuous grassland increased SOC in the soil profile with highest gains in the first 30 cm, while losses were recorded under continuous cropping. Where temporary grasslands were introduced into cropping cycles, SOC stocks were maintained. These observations were only partly confirmed when changing the scale of observation to 3-ha blocks. At the 3-ha scale, most grassland treatments exhibited both gains and losses of SOC, which could be partly related to soil physicochemical properties. Overall, our data suggest that both management practices and soil characteristics determine if carbon will accumulate in SOC pools. For detailed understanding of SOC changes, a combination of measurements at different scales is necessary. [ABSTRACT FROM AUTHOR]

Peatlands act as a powerful carbon (C) sink. This specificity notably results from their particular environment, composed of Shagnum mosses, and the acidic state of the soil combined with a high water saturation that strongly limit organic matter decomposition. Future natural and anthropogenic global changes are expected to modify peatlands functioning and notably their species composition, which could reverse their valuable role in C sequestration and thus in climate change mitigation. However, the response of peatlands to these biotic changes, and thus the variability of greenhouse gas fluxes, remains poorly characterized and understood. We investigated CO2 and CH4 emissions in the La Guette peatland, an acidic fen located in the center of France, thanks to an Eddy-covariance station that was installed in the ecosystem in early 2017. In addition, this site is applying for the ICOS network labelling as an associated site, and follows the ICOS recommendations. Our main concern is that La Guette peatland is submitted to a strong domination by a grass plant, Molinia caerulea, which is suspected to modify the C dynamic of the ecosystem. From January 2017 to date, CO2 and CH4 fluxes to the atmosphere ranged from to -19.46 to 19.73 µmol m-2 s-1 and from -0.10 to 0.10 µmol m-2 s-1, respectively. Mean CO2 flux for 2017 and 2018 were respectively ~ -0.21 and ~ -0.89 µmol m-2 s-1, showing that La Guette peatland acted as a sink of C over these two years. This result suggests that Molinia caerulea did not reverse the C sequestration potential of the fen. In a larger scale, this Eddy-covariance station is a part of a French Peatland Observatory Service, and is included in a network of three tower fluxes deployed in three contrasted French peatlands. This Eddy-covariance network will provide important data that will help to understand the evolution of the C balance in temperate peatlands with global changes. [ABSTRACT FROM AUTHOR]

The Mediterranean area is particularly sensitive to climate change and has been identified as one of the most noticeable "hot-spots" for future projections. Assessment of the evolution of surface water resources is here a key challenge to manage future socio-economic pressure. For the coastal Mediterranean rivers draining to the Gulf of Lions in southern France, our previous studies already identified a 20% decrease of water discharge for the period of 1965-2004 in relation to global warming (+1.5 °C/ 40 yrs), despite stationary evolutions of precipitation. Statistically significant trends were restricted to specific areas such as the headwater catchments in the Pyrenees mountains where reduced snowfall could explain the decreasing water discharge trends. However, including the most recent years (up to 2017), the time series demonstrate that the decline in water discharge still continued and now uniformly applies to all coastal rivers in this area. Water discharge could consequently have been reduced by more than 40% since the years 1960. Such a strong decline in the available surface water resources is a major thread for sustainable agricultural land use in this area. In order to test this hypothesis, we first updated our hydroclimatic trend analysis including longer time series (1958-2017) and additional parameters (including the spatialized and gridded climatological stations "Safran-Isba" of Meteo France) in order to better understand the climatic forcing of water discharge and identify the most vulnerable areas to recent climate change. These data will be then compared to the corresponding evolution of agricultural land use practices and the hydroclimatic constraints which are considered to allow optimal productions. For the development of possible mitigation strategies, we finally also focus in a special case study on the Tet River Basin where queries on farmers and agricultural institutions will supply additional information. This river basin is particularly interesting as agriculture relies here strongly on a sophisticated and water consuming irrigation network. [ABSTRACT FROM AUTHOR]