David Leclère

• PhD, Env. Sc., AgroParisTech
• Researcher at International Institute for Applied Systems Analysis

The Fisheries and Marine Ecosystems Model Intercomparison Project (FishMIP) has dedicated a decade to unraveling the future impacts of climate change on marine animal biomass. FishMIP is now preparing a new simulation protocol to assess the combined effects of both climate and socio‐economic changes on marine fisheries and ecosystems. This protocol...

The European Union is committed to achieving ambitious area-based conservation and restoration targets in the upcoming decade. However, there is concern that these targets risk conflicting with socio-economic needs, particularly for food, timber, and bioenergy production. Here, we develop an integrated spatial planning approach to identify where re...

Although reactive nitrogen (Nr) emissions from food and energy production contribute to multi-dimensional environmental damages, integrated management of Nr is still lacking owing to unclear future mitigation potentials and benefits. Here, we find that by 2050, high-ambition compared to low-ambition N interventions reduce global ammonia and nitroge...

The rapid urbanization in Africa profoundly affects local food and ecological systems. According to earlier research, urbanization may cause food production and biodiversity losses as agricultural or natural lands are absorbed by expanding cities. Land-use displacement effects may buffer agricultural production losses or may lead to additional biod...

The Fisheries and Marine Ecosystems Model Intercomparison Project (FishMIP) has dedicated a decade to unravelling the future impacts of climate change on marine animal biomass. FishMIP is now preparing a new simulation protocol to assess the combined effects of both climate and socio-economic changes on marine fisheries and ecosystems. This protoco...

To reduce the biodiversity impact of agriculture, increasing yields on existing farmland has been proposed as an alternative to farmland expansion. However, the relative effects of yield increases versus agricultural expansion have mostly been examined regionally, and measured in terms of species persistence—a metric relevant to extinction risk but...

Based on an extensive model intercomparison, we assessed trends in biodiversity and ecosystem services from historical reconstructions and future scenarios of land-use and climate change. During the 20th century, biodiversity declined globally by 2 to 11%, as estimated by a range of indicators. Provisioning ecosystem services increased several fold...

The European Union is committed to achieving ambitious area-based conservation and restoration targets in the upcoming decade. Yet, there is concern that these targets may conflict with societal needs, particularly food and timber production. Ensuring that competing demands for land are balanced, while the underlying objectives of these targets to...

The European Union is committed to achieving ambitious area-based conservation and restoration targets in the upcoming decade. However, there is concern that these targets risk conflicting with socio-economic needs, particularly for food, timber, and bioenergy production. Here, we develop an integrated spatial planning approach to identify where re...

The rapid urbanization in Africa profoundly affects local food and ecological systems. According to earlier research, urbanization may cause food production and biodiversity losses as agricultural or natural lands are absorbed by expanding cities. Although land use displacement effects may potentially buffer agricultural production losses or lead t...

Plant-based animal product alternatives are increasingly promoted to achieve more sustainable diets. Here, we use a global economic land use model to assess the food system-wide impacts of a global dietary shift towards these alternatives. We find a substantial reduction in the global environmental impacts by 2050 if globally 50% of the main animal...

The Nature Futures Framework (NFF) is a heuristic tool for co-creating positive futures for nature and people. It seeks to open up a diversity of futures through mainly three value perspectives on nature – Nature for Nature, Nature for Society, and Nature as Culture. This paper describes how the NFF can be applied in modelling to support decision-m...

The Kunming-Montreal Global Biodiversity Framework is a worldwide plan to urgently address and reverse biodiversity loss, intending to achieve a harmonious relationship between humanity and nature by 2050. This paper seeks to contribute to operationalising the framework, specifically concerning biodiversity conservation and nature's contributions t...

Working paper analysing the economic implications of the proposed 30% target for areal protection in the draft post-2020 Global Biodiversity Framework

Achieving sustainable development requires understanding how human behavior and the environment interact across spatial scales. In particular, knowing how to manage tradeoffs between the environment and the economy, or between one spatial scale and another, necessitates a modeling approach that allows these different components to interact. Existin...

Agricultural expansion to meet humanity’s growing needs for food and materials is a leading driver of land-use change, exacerbating climate change and biodiversity loss. Seaweed biomass farmed in the ocean could help reduce demand for terrestrial crops and reduce agricultural greenhouse gas emissions by providing a substitute or supplement for food...

Citation: United Nations Environment Programme (2022). Strengthening Synergies: Climate change mitigation benefits from achieving global biodiversity targets. United Nations Environment Programme World Conservation Monitoring Centre, Cambridge. Key messages: 1. Well-directed action to conserve and restore biodiversity in line with the targets bein...

p>In this article, the abstract has been revised such that “30% of the total CO₂ increase in the atmosphere since the Industrial Revolution” now reads “30% of the total CO₂ increase in the atmosphere, or 14% of total emissions, since the Industrial Revolution.” In addition, the second paragraph in the “Priority areas for resto...

Developing and integrating agricultural markets may be key to addressing Africa’s sustainability challenges. By modelling trade costs from farm gate to potential import markets across eight African regions, we investigate the impact of individual components of continental free trade and the complementary role of domestic agricultural development th...

Governments are negotiating actions intended to halt biodiversity loss and put it on a path to recovery by 2050. Here, we show that bending the curve for biodiversity is possible, but only if actions are implemented urgently and in an integrated manner. Connecting these actions to biodiversity outcomes and tracking progress remain a challenge.

Human impacts on the Earth’s biosphere are driving the global biodiversity crisis. Governments are preparing to agree on a set of actions intended to halt the loss of biodiversity and put it on a path to recovery by 2050. We provide evidence that the proposed actions can bend the curve for biodiversity, but only if these actions are implemented urg...

EXPERT INPUT TO THE POST-2020 GLOBAL BIODIVERSITY FRAMEWORK: TRANSFORMATIVE ACTIONS ON ALL DRIVERS OF BIODIVERSITY LOSS ARE URGENTLY REQUIRED TO ACHIEVE THE GLOBAL GOALS BY 2050

Trade liberalization in the early 21st century increased the adaptation capacity of global food systems to climate change; further liberalization and trade facilitation could help to avoid dozens of millions being undernourished at mid-century. The global trade agenda should explicitly include climate change adaptation to achieve SDG 2 Zero Hunger....

While nitrogen inputs are crucial to agricultural production, excess nitrogen contributes to serious ecosystem damage and water pollution. Here, we investigate this trade-off using an integrated modelling framework. We quantify how different nitrogen mitigation options contribute to reconciling food security and compliance with regional nitrogen su...

The Nature Futures Framework (NFF) is a heuristic tool for co-creating positive futures for nature and people. It seeks to open up a diversity of futures through mainly three value perspectives on nature – Nature for Nature, Nature for Society, Nature as Culture. In this paper, we describe how the NFF can be applied in modelling to support policy....

Input–output estimates of nitrogen on cropland are essential for improving nitrogen management and better understanding the global nitrogen cycle. Here, we compare 13 nitrogen budget datasets covering 115 countries and regions over 1961–2015. Although most datasets showed similar spatiotemporal patterns, some annual estimates varied widely among th...

Stochastic agro-economic model GLOBIOM is used to demonstrate how best to design and evaluate the CAP’s financial and structural measures, both individually and jointly, in the face of inherent uncertainty and risk. The model accounts for plausible shocks simultaneously and derives measures that are robust against all shock scenarios; it can thus h...

Extensive ecosystem restoration is increasingly seen as being central to conserving biodiversity¹ and stabilizing the climate of the Earth². Although ambitious national and global targets have been set, global priority areas that account for spatial variation in benefits and costs have yet to be identified. Here we develop and apply a multicriteria...

EXECUTIVE SUMMARY The global Living Planet Index continues to decline. It shows an average 68% decrease in population sizes of mammals, birds, amphibians, reptiles and fish between 1970 and 2016. A 94% decline in the LPI for the tropical subregions of the Americas is the largest fall observed in any part of the world. Why does this matter? It matte...

Increased efforts are required to prevent further losses to terrestrial biodiversity and the ecosystem services that it provides1,2. Ambitious targets have been proposed, such as reversing the declining trends in biodiversity³; however, just feeding the growing human population will make this a challenge⁴. Here we use an ensemble of land-use and bi...

International trade enables us to exploit regional differences in climate change impacts and is increasingly regarded as a potential adaptation mechanism. Here, we focus on hunger reduction through international trade under alternative trade scenarios for a wide range of climate futures. Under the current level of trade integration, climate change...

Brazilian agricultural production provides a significant fraction of the food consumed globally, with the country among the top exporters of soybeans, sugar, and beef. However, current advances in Brazilian agriculture can be directly impacted by climate change and resulting biophysical effects. Here, we quantify these impacts until 2050 using GLOB...

Despite the scientific consensus on the extinction crisis and its anthropogenic origin, the quantification of historical trends and of future scenarios of biodiversity and ecosystem services has been limited, due to the lack of inter-model comparisons and harmonized scenarios. Here, we present a multi-model analysis to assess the impacts of land-us...

Humanity's transformation of the nitrogen cycle has major consequences for ecosystems, climate and human health, making it one of the key environmental issues of our time. Understanding how trends could evolve over the course of the 21st century is crucial for scientists and decision-makers from local to global scales. Scenario analysis is the prim...

Despite their limited spatial extent, freshwater ecosystems host remarkable biodiversity, including one third of all vertebrate species. This biodiversity is declining dramatically: globally, wetlands are vanishing three times faster than forests, and freshwater vertebrate populations have fallen more than twice as steeply as terrestrial or marine...

The workshop drew on the ‘nature futures’ participatory scenario-building exercise initiated by the IPBES expert group on scenarios and models, and other biodiversity modelling initiatives such as the ISIMIP project2 working on adding biodiversity to the Shared Socioeconomic Pathways (SSPs) scenarios framework, the 'bending the curve' initiative3 l...

Biological invasions have emerged as an eminent feature of global change, with substantial impacts on the environment and human livelihoods. Current research demonstrates that the numbers and impacts of alien species are rising unabatedly. At the same time, we lack a thorough understanding of potential future trajectories for the decades to come. W...

The report represents the first coordinated effort by researchers from 17 countries to chart long-term pathways towards sustainable land-use and food systems.

The Indus River Basin faces severe water quality degradation because of nutrient enrichment from human activities. Excessive nutrients in tributaries are transported to the river mouth, causing coastal eutrophication. This situation may worsen in the future because of population growth, economic development, and climate change. This study aims at a...

To support the assessments of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the IPBES Expert Group on Scenarios and Models is carrying out an intercomparison of biodiversity and ecosystem services models using harmonized scenarios (BES-SIM). The goals of BES-SIM are (1) to project the global impacts o...

Stochastic agro-economic model GLOBIOM is used to demonstrate how best to design and evaluate the CAP’s financial and structural measures, both individually and jointly, in the face of inherent uncertainty and risk. The model accounts for plausible shocks simultaneously and derives measures that are robust against all shock scenarios; it can thus h...

To support the assessments of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the IPBES Expert Group on Scenarios and Models is carrying out an intercomparison of biodiversity and ecosystem services models using harmonized scenarios (BES-SIM). The goals of BES-SIM are (1) to project the global impacts o...

Agriculture is one of the sectors that is expected to be most significantly impacted by climate change. There has been considerable interest in assessing these impacts and many recent studies investigating agricultural impacts for individual countries and regions using an array of models. However, the great majority of existing studies explore impa...

Unless actions are taken to reduce multiple anthropogenic pressures, biodiversity is expected to continue declining at an alarming rate. Models and scenarios can be used to help design the pathways that sustain a thriving nature and its ability to contribute to people. This approach has so far been hampered by the complexity associated with combini...

Understanding the interplay between multiple climate change risks and socioeconomic development is increasingly required to inform effective actions to manage these risks and pursue sustainable development. We calculate a set of 14 impact indicators at different levels of global mean temperature (GMT) change and socioeconomic development covering w...

To support the assessments of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the IPBES Expert Group on Scenarios and Models is carrying out an intercomparison of biodiversity and ecosystem services models using harmonized scenarios (BES-SIM). The goals of BES-SIM are (1) to project the global impacts o...

Russia and Ukraine are countries with relatively large untapped agricultural potentials, both in terms of abandoned agricultural land and substantial yield gaps. Here we present a comprehensive assessment of Russian and Ukrainian crop production potentials and we analyze possible impacts of their future utilization, on a regional as well as global...

In order to conduct research at required spatial resolution, we propose a model fusion involving interlinked calculations of regional projections by the global dynamic model GLOBIOM (Global Biosphere Management Model) and robust dynamic downscaling model, based on cross-entropy principle, for deriving spatially resolved projections. The proposed pr...

The interdependencies among land use systems at national and global levels motivate the development of advanced systems analysis approaches for integration of land use models operating at different weights. The paper develops novel general approaches based on cross entropy principle for downscaling aggregate data and projections, which are robust w...

Climate change has the potential to impair livestock health, with consequences for animal welfare, productivity, greenhouse gas emissions, and human livelihoods and health. Modelling has an important role in assessing the impacts of climate change on livestock systems and the efficacy of potential adaptation strategies, to support decision making f...

Heat exposure strongly affects the health and productivity of livestock species and plays a strong role in the current distribution of livestock species and productivity across the world (Collier and Gebremedhin, 2015). Various models of underlying processes have been developed since the mid-20th century. However, the impact of current level of liv...

Interdependencies among land use systems resemble a complex network connected through demand–supply relationships. Disruption of this network may catalyse systemic risks affecting food, energy, water and environmental security (FEWES) worldwide. We describe the conceptual development, expansion and practical application of a stochastic version of t...

Using econometric models to estimate land-use change has a long tradition in literature. Recent contributions show the importance of including spatial information and of using a multi-nomial framework to take into account the inter-dependencies between the land-use classes. Few studies, however, agree on the relevant determinants of land-use change...

The aim of this study is to discuss robust, non-Bayesian, probabilistic, cross-entropy-based disaggregation (downscaling) techniques. Systems analysis of global change (including climate) processes requires new approaches to integrating and rescaling of models, data, and decision-making procedures between various scales. For example, in the analysi...

This paper conducts an integrated assessment of climate change impacts and climate mitigation on agricultural commodity markets and food availability in low- and middle-income countries. The analysis uses the partial equilibrium model GLOBIOM to generate scenarios to 2080. The findings show that climate change effects on the agricultural sector wil...

■ Climate change impacts on crop and grass yields are projected to have only small effect on global milk and meat production by 2050, which remains under any climate scenario within +/-2 percent of the projected production without climate change. ■ Depending on the scenario, the climate change effects can be more pronounced at the regional scale. I...

The paper focuses on the development of adequate approaches to the systems analysis of geographically-explicit robust decisions for long-term consistent management of interdependent land use systems. We introduce a stochastic partial equilibrium Global Biosphere Management Model (GLOBIOM) enabling to analyze secure food, energy, and water provision...

Climate change might impact crop yields considerably and anticipated transformations of agricultural systems are needed in the coming decades to sustain affordable food provision. However, decision-making on transformational shifts in agricultural systems is plagued by uncertainties concerning the nature and geography of climate change, its impacts...

The impact of climate change on European agriculture is subject to a significant uncertainty, which reflects the intertwined nature of agriculture. This issue involves a large number of processes, ranging from field to global scales, which have not been fully integrated yet. In this study, we intend to help bridging this gap by quantifying the effe...

Les systèmes agricoles sont intimement liés au changement climatique : ils sont d'une part affectés par la dérive de son état moyen et de sa variabilité, et sont d'autre part des contributeurs nets à l'évolution du climat par l'extension de leur surface et l'intensité de leur gestion. L'évolution du système climat-agriculture repose sur nombreux mé...

Assessing climate change impact on agriculture is a complex task involving a wide range of economical and physical processes, leading to significant uncertainties. At European scale, climate change impacts on agricultural supply have been appraised to be of relatively less important driver by the end of century compared to other global drivers. How...

We present here preliminary results of an integrated modelling approach combining a crop model (STICS) and an economic model (AROPAj) of European agricultural supply. This modelling framework is designed to perform quantitative analysis, regarding climate change impacts on agriculture and more generally the interactions between soils, land use, agr...

Climate change impacts on agriculture have been appraised with various methodologies and tools for more than two decades, and cover a wide range issues from biological processes at the crop level to worldwide economy. However, the role of farm-scale processes on land-uses has not yet been assessed at a continental scale in this context. We herein p...