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Understanding uncertainties in land cover projections is critical to investigating land-based climate mitigation policies, assessing the potential of climate adaptation strategies and quantifying the impacts of land cover change on the climate system. Here, we identify and quantify uncertainties in global and European land cover projections over a diverse range of model types and scenarios, extending the analysis beyond the agro-economic models included in previous comparisons. The results from 75 simulations over 18 models are analysed and show a large range in land cover area projections, with the highest variability occurring in future cropland areas. We demonstrate systematic differences in land cover areas associated with the characteristics of the modelling approach, which is at least as great as the differences attributed to the scenario variations. The results lead us to conclude that a higher degree of uncertainty exists in land use projections than currently included in climate or earth system projections. To account for land use uncertainty, it is recommended to use a diverse set of models and approaches when assessing the potential impacts of land cover change on future climate. Additionally, further work is needed to better understand the assumptions driving land use model results and reveal the causes of uncertainty in more depth, to help reduce model uncertainty and improve the projections of land cover.

Rice is one of the most important grain crops in Northeast China (NEC) and its cultivation is sensitive to climate change. This study aimed to explore the spatio-temporal changes in the NEC rice planting area over the period of 1980–2010 and to analyze their relationship to climate change. To do so, the CLUE-S (conversion of land use and its effects at small region extent) model was first updated and used to simulate dynamic changes in the rice planting area in NEC to understand spatio-temporal change trends during three periods: 1980–1990, 1990–2000 and 2000–2010. The changing results in individual periods were then linked to climatic variables to investigate the climatic drivers of these changes. Results showed that the NEC rice planting area expanded quickly and increased by nearly 4.5 times during 1980–2010. The concentration of newly planted rice areas in NEC constantly moved northward and the changes were strongly dependent on latitude. This confirmed that climate change, increases in temperature in particular, greatly influenced the shift in the rice planting area. The shift in the north limit of the NEC rice planting area generally followed a 1°C isoline migration pattern, but with an obvious time-lag effect. These findings can help policy makers and crop producers take proper adaptation measures even when exposed to the global warming situation in NEC.

Although climate change impacts and agricultural adaptations have been studied extensively, how smallholder farmers perceive climate change and adapt their agricultural activities is poorly understood. Survey-based data (presents farmers' personal perceptions and adaptations to climate change) associated with external biophysical-socioeconomic data (presents real-world climate change) were used to develop a farmer-centered framework to explore climate change impacts and agricultural adaptations at a local level. A case study at Bin County (1980s–2010s), Northeast China, suggested that increased annual average temperature (0.6°C per decade) and decreased annual precipitation (46 mm per decade, both from meteorological datasets) were correctly perceived by 76 and 66.9%, respectively, of farmers from the survey, and that a longer growing season was confirmed by 70% of them. These reasonably correct perceptions enabled local farmers to make appropriate adaptations to cope with climate change: Longer season alternative varieties were found for maize and rice, which led to a significant yield increase for both crops. The longer season also affected crop choice: More farmers selected maize instead of soybean, as implicated from survey results by a large increase in the maize growing area. Comparing warming-related factors, we found that precipitation and agricultural disasters were the least likely causes for farmers' agricultural decisions. As a result, crop and variety selection, rather than disaster prevention and infrastructure improvement, was the most common ways for farmers to adapt to the notable warming trend in the study region.

Previous analyses have shown that cropland in China is intensifying, leading to an increase in crop production. However, these output measures leave the potential for further intensification largely unassessed. This study uses the harvested area gap (HAG), which expresses the amount of harvested area that can be gained if all existing cropland is harvested as frequently as possible, according to their potential limit for multi-cropping. Specifically, we calculate the HAG and changes in the HAG in China between 1981 and 2010. We further assess how climatic and land management factors affect these changes. We find that in China the HAG decreases between the 1980s and the 1990s, and subsequently increases between the 1990s and the 2000s, resulting in a small net increase for the entire study period. The initial decrease in the HAG is the result of an increase in the average multi-cropping index throughout the country, which is larger than the increase in the potential multi-cropping index as a result of the changed climatic factors. The subsequent increase in the HAG is the result of a decrease in average multi-cropping index throughout the country, in combination with a stagnant potential. Despite the overall increase in harvested area in China, many regions, e.g. Northeast and Lower Yangtze, are characterized by an increased HAG, indicating their potential for further increasing the multi-cropping index. The study demonstrates the application of the HAG as a method to identify areas where the harvested area can increase to increase crop production, which is currently underexplored in scientific literature.

In this study, we produced a spatially explicit diagnosis of the deforestation hotspots and future climate risk (2050) of cocoa producing areas, zooming into the top 8 cocoa exporting countries and the main global cocoa traders. Cocoa-driven deforestation often co-occurs with deforestation driven by other agri-commodities, and thus needs to be tackled jointly. Climate risk will be substantially increased in Cote d'Ivoire and Ghana, the two most important suppliers of cocoa, which may lead to supply failures and severe socio-economic impacts if left unaddressed. Climate risk and deforestation have a high spatial variability between and within countries, calling for geographically differentiated approaches to mitigation and adaptation. Large transnational traders depending heavily on West African supplies, as well as the regionally based exporting farmer cooperatives and domestic firms, will be affected by the increased climate risk in that region. Traders operating in Latin America and Southeast Asia might only face a modest increase in climate risk, with subregional exceptions. These results raise concerns about the validity of sustainability commitments made by companies and other sector initiatives, which focus on single commodities and fail to consider the diversity of actors adding pressure on landscapes. Tackling these issues requires a collaborative effort from various sectors and stakeholders involved in land use decisions to prevent the geographical displacement of negative impacts, prioritize urgent action, and implement these changes efficiently and in a coordinated manner. Further, sustainability commitments often neglect climate change adaptation, with agroforestry and climate smart agriculture initiatives primarily focusing on carbon reductions and increased farmer income, paying less attention to farm practices that reduce cocoa vulnerability. • Cocoa is one of many drivers of deforestation and assessments must consider competing sectors in a landscape. • No-deforestation initiatives must integrate all sectors competing for agricultural land to avoid displacing impacts. • Global cocoa supply is at risk if climate risk is unaddressed among West African smallholder farmers. • Horizontally-integrated traders are key to implementing landscape approaches especially where agri-commodities overlap. [ABSTRACT FROM AUTHOR]

Climate change is expected to have strong implications for smallholder coffee farmers and implementing adaptation measures would lessen their vulnerabilities. Adaptation measures have been identified in literature, but how these can be implemented remains unclear. Current certification programmes have the potential to provide guidance on how sustainability criteria can be addressed and taken up by farmers. We identify climate change adaptation options, their scale of application, and the necessary implementation steps. We show that implementation complexity strongly increases with the degree of climate change. With modest climatic changes, incremental adaptations might suffice, but more substantial climatic change will require radical social-institutional changes for adaptation uptake and interventions. For the majority of smallholders the implementation of any measure is largely constrained by a lack of access to knowledge networks and training material, organisational support, and (mainly financial) resources. A landscape approach that encompasses collective action and coordinated cross-sector planning can overcome some of these barriers. Certification approaches can facilitate a move in this direction. Yet, the implementation of transformative adaptations requires visioning, realignment of policies and incentives, and new market formations. This entails a repositioning and revision of certification schemes to allow for more effective adaptation uptake for the benefit of smallholders and the environment. [ABSTRACT FROM AUTHOR]

Highlights • Europe's cultural landscapes are threatened by urbanization and abandonment. • Different cultural landscapes are sensitive to different types of landscape change. • The future of low-intensity, culturally valuable landscapes is scenario dependent. Abstract Cultural landscapes are valued for their landscape character and cultural heritage. Yet, these often low-intensity, multifunctional landscapes are at risk of disappearance. Understanding how cultural landscapes might change under alternative futures is important for identifying where to target actions towards persistence of cultural landscapes. This study therefore aims to identify past and future land use changes in the European Union's (EU's) cultural landscapes. To do so, we overlay past and projected plausible future land change trajectories with the spatial distribution of cultural landscapes in the EU. Our results highlight a clear co-occurrence of specific land change trajectories and cultural landscape types. Past and future urbanization and agricultural abandonment are the land use change processes most strongly affecting small-scale, low-intensity agricultural landscapes that are valued by society. De-intensification is overrepresented in landscapes with a low management intensity. Past intensification was overrepresented in small-scale landscapes with a high value to society, while future intensification might concentrate on landscapes with a low intensity. Typical cultural landscapes show a strong variation of changes under different scenario conditions in terms of future landscape change. Scenario analysis revealed that some of the threats to cultural landscapes are related to agricultural policies, nature policies and other spatial restrictions. At the same time, these policies may also alleviate these threats when properly designed and targeted by accounting for the impacts they may have on cultural landscapes. Considering cultural landscapes more directly in decisions to be made for the post-2020 Common Agricultural Policy period is needed, and could be achieved by a focus on landscape quality beyond the current focus on specific greening measures. [ABSTRACT FROM AUTHOR]

The Mediterranean region faces significant challenges to supply its growing population with food and living space. The region’s potential to do so in the future is even more uncertain in the light of global change effects. Climate change will impact water availability in the region, which is already limited and often used at unsustainable rates. To investigate the effects of global change and explore alternative development pathways of Mediterranean land use, we simulated two future scenarios with different land, water and biodiversity management transitions. We adopted a land systems approach, where land use and land cover are combined with data on land management, irrigation and livestock density, taking into account the characteristics of Mediterranean multifunctional landscapes, specific agricultural products, such as permanent crops, and irrigation water demands. Future land system changes were explored using the CLUMondo model for different development pathways of the region. We constrained the withdrawal of irrigation water based on existing freshwater resources. In a ‘growth’ scenario, we simulated a hypothetical future without consideration of environmental constraints and where food production and urban expansion are main priorities. The ‘sustainability’ scenario represents a future where limited water resources are extracted in a sustainable way and where areas of high biodiversity value are protected. The growth scenario projected significant intensification of land management, and loss of agro-silvo-pastoral mosaic systems. To achieve this, we calculate that the region would need to increase water withdrawal for irrigation significantly, resulting in increased pressure on freshwater resources. The sustainability scenario presents a way of increasing food production and at the same time improving the state of water resources, wetlands and traditional landscapes. Achieving this future would require improvements of yields of rain-fed systems and efficiencies of irrigated systems. The results indicate that coordinated environmental policy together with appropriate market access are needed to steer the regions land management towards a more sustainable future while ensuring food production. [ABSTRACT FROM AUTHOR]

Sustainable agricultural intensification is needed to tackle food insecurity and global environmental change. Local environmental conditions determine the needs and potentials for increasing sustainability of agricultural practices. However, the potential for implementation also depends on socio-economic factors, as farmers need to adopt innovative farming practices, and consumer demand affects the economic feasibility. This study aims to map opportunities for sustainable intensification in Europe taking into account farmer characteristics, consumer behaviour, environmental pressures, and unexploited agronomic potentials. In areas identified as having high opportunities, we estimate the impacts of specific sustainable intensification measures on both intensification (in terms of calorie gains) and sustainability (in terms of resource savings). The study finds high spatial variation in opportunities for sustainable intensification across Europe. High opportunities for sustainable intensification are found on 34% of the arable area in Europe. In addition, the analysis shows that a combination of different measures can simultaneously improve food security and sustainability. [ABSTRACT FROM AUTHOR]

Land use is a cornerstone of human civilization, but also intrinsically linked to many global sustainability challenges—from climate change to food security to the ongoing biodiversity crisis. Understanding the underlying technological, institutional and economic drivers of land-use change, and how they play out in different environmental, socio-economic and cultural contexts, is therefore important for identifying effective policies to successfully address these challenges. In this regard, much can be learned from studying long-term land-use change. We examined the evolution of European land management over the past 200 years with the aim of identifying (1) key episodes of changes in land management, and (2) their underlying technological, institutional and economic drivers. To do so, we generated narratives elaborating on the drivers of land use-change at the country level for 28 countries in Europe. We qualitatively grouped drivers into land-management regimes, and compared changes in management regimes across Europe. Our results allowed discerning seven land-management regimes, and highlighted marked heterogeneity regarding the types of management regimes occurring in a particular country, the timing and prevalence of regimes, and the conditions that result in observed bifurcations. However, we also found strong similarities across countries in the timing of certain land-management regime shifts, often in relation to institutional reforms (e.g., changes in EU agrarian policies or the emergence and collapse of the Soviet land management paradigm) or to technological innovations (e.g., drainage pipes, tillage and harvesting machinery, motorization, and synthetic fertilizers). Land reforms frequently triggered changes in land management, and the location and timing of reforms had substantial impacts on land-use outcomes. Finally, forest protection policies and voluntary cooperatives were important drivers of land-management changes. Overall, our results demonstrate that land-system changes should not be conceived as unidirectional developments following predefined trajectories, but rather as path-dependent processes that may be affected by various drivers, including sudden events. [ABSTRACT FROM AUTHOR]

Agricultural land use in Europe has changed considerably in the last decades. However, our understanding of agricultural land use changes, especially changes in land use intensity, is limited because the evidence is fragmented. This paper presents a systematic review of case study evidence on manifestations and underlying drivers for agricultural land use change in Europe. We analyzed 137 studies that together report on 76 cases of intensification and 143 cases of disintensification. Observed changes were manifested as expansion or contraction of agricultural land as well as in changes of land management intensity, landscape elements, agricultural land use activity, and specialization/diversification. Economic, technological, institutional and location factors were frequently identified as underlying drivers, while demographic drivers and sociocultural drivers were mentioned less often. In addition, we found that farmers were very important as moderators between underlying drivers and manifestations of agricultural land use change. Farmer decisions differed between different farmer types, and according to their characteristics and attitudes. We found major land use change trajectories in relation to globalization of agricultural markets, the transition from a rural to an urban society, and the shift to post-socialism in central and eastern Europe. [ABSTRACT FROM AUTHOR]

• We map megatrends to gain foresight on the future of European agriculture. • Mapped megatrends are climate, demography, value system, and environmental regulation. • Different regions face pressures from different combinations of megatrends. • Regions range from highly susceptible to systemic change to highly persistent. • For sustainability transitions, megatrends inform what governance is needed. A range of intensifying pressures is making the future of European agriculture dynamic and contested. Insights into these pressures are needed to inform debates about the future of the sector. In this study, we use a foresight approach to identify, quantify and map megatrends. Megatrends are long-term driving forces which are observable today and will likely have transformational potential in the future. By mapping these megatrends at the regional scale, we establish a geography of megatrends and detect where they coincide. Four megatrends significant for the future of European agriculture at the regional scale are assessed: Climate change, demographic change, (post-) productivism shifts, and increasingly stringent environmental regulations. The direction and intensity of these megatrends differs between regions, which drives regions into different systemic lock-ins or dynamics. In most regions, megatrends converge to destabilize the current system, forewarning impending systemic changes. While the specific megatrends contributing to this instability differ regionally, this result highlights that many regions are on a dynamic rather than stable trajectory, and the governance challenge is to steer these dynamics towards a desirable future. However, some regions are found to be highly persistent, indicating that megatrends reinforce business as usual, and change needs to be triggered through purposeful governance. In a minority of regions megatrends may drive marginalization as the current system becomes increasingly unviable. We argue that research and policies concerning agricultural sustainability transitions should be cognizant of the regional diversity of European megatrends and the pressures they create. [ABSTRACT FROM AUTHOR]

A primary goal of Earth system modelling is to improve understanding of the interactions and feedbacks between human decision making and biophysical processes. The nexus of land use and land cover change (LULCC) and the climate system is an important example. LULCC contributes to global and regional climate change, while climate affects the functioning of terrestrial ecosystems and LULCC. However, at present, LULCC is poorly represented in Global Circulation Models (GCMs). LULCC models that are explicit about human behaviour and decision making processes have been developed at local to regional scales, but the principles of these approaches have not yet been applied to the global scale level in ways that deal adequately with both direct and indirect feedbacks from the climate system. In this article, we explore current knowledge about LULCC modelling and the interactions between LULCC, GCMs and Dynamic Global Vegetation Models (DGVMs). In doing so, we propose new ways forward for improving LULCC representations in Earth System Models. We conclude that LULCC models need to better conceptualise the alternatives for up-scaling from the local to global. This involves better representation of human agency, including processes such as learning, adaptation and agent evolution, formalising the role and emergence of governance structures, institutional arrangements and policy as endogenous processes and better theorising about the role of tele-connections and connectivity across global networks. Our analysis underlines the importance of observational data in global scale assessments and the need for coordination in synthesising and assimilating available data. [ABSTRACT FROM AUTHOR]

Currently, up to 30% of global carbon emission is estimated to originate from land use and land changes. Existing historic land change reconstructions on the European scale do not sufficiently meet the requirements of greenhouse gas (GHG) and climate assessments, due to insufficient spatial and thematic detail and the consideration of various land change types. This paper investigates if the combination of different data sources, more detailed modeling techniques and the integration of land conversion types allow us to create accurate, high resolution historic land change data for Europe suited for the needs of GHG and climate assessments. We validated our reconstruction with historic aerial photographs from 1950 and 1990 for 73 sample sites across Europe and compared it with other land reconstructions like Klein Goldewijk et al. (2010, 2011), Ramankutty and Foley (1999), Pongratz et al. (2008) and Hurtt et al. (2006). The results indicate that almost 700 000 km² (15.5 %) of land cover in Europe changes over the period 1950 to 2010, an area similar to France. In Southern Europe the relative amount was almost 3.5% higher than average (19 %). Based on the results the specific types of conversion, hot-spots of change and their relation to political decisions and socioeconomic transitions were studied. The analysis indicate that the main drivers of land change over the studied period were urbanization, the reforestation program after the timber shortage since the Second World War, the fall of the Iron Curtain, Common Agricultural Policy and accompanying afforestation actions of the EU. Compared to existing land cover reconstructions, the new method takes stock of the harmonization of different datasets by achieving a high spatial resolution and regional detail with a full coverage of different land categories. These characteristic allow the data to be used to support and improve ongoing GHG inventories and climate research. [ABSTRACT FROM AUTHOR]

Model predictions on the response of soil processes to global warming are mostly inferred from small-scale laboratory studies. In this study, a forested catchment in southern Norway was enclosed by a greenhouse and experimentally manipulated by increasing CO[sub 2] (+200 µl 1[sup -1] above ambient) and temperature (+3-5°C). This paper reports on the effects of the climate manipulation on N mineralization and nitrification. We measured net N mineralization and nitrification in a control and treated part of the greenhouse as well as in an uncovered reference catchment in plots dominated by Calluna vulgaris (L.) Hull or Vaccinium myrtillus L. Net N mineralization in the 0-10 cm soil layer significantly increased, most likely as a result of increased temperature. The effect was largest in plots dominated by Calluna. Nitrification did not significantly increase. Soil moisture inside the incubated cores was not affected by the climate change treatment. Pre-treatment mineralization was similar inside and outside the enclosure whereas nitrification was higher inside the enclosure. The NH[sub 4, sup +] content was significantly lower inside the chamber due to removal of acidifying components from the precipitation and lower inputs of dry deposition. We found however no differences in Ph, %C and %N of the LF and H layer and total C and N in the soil cores between the two catchments. Mineralization was generally higher under Vaccinium than under Calluna even though measured soil chemical and physical characteristics were similar. Nitrification was higher under Calluna than under Vaccinium. [ABSTRACT FROM AUTHOR]