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Biodiversité et services écosystémiques : une évaluation globale de leurs tendances

1. What is the IPBES?

    The IPBES is the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. It was established in 2012 and is comprised of 130 member governments. Its objective is to provide up-to-date and independent scientific assessments on biodiversity and ecosystems, so that governments, the private sector and civil society can make better-informed decisions.

    contributing authors, and that included the findings of more than 15 000 scientific publications. It is the first global assessment of its scope since the millennium ecosystem assessment published in 2005. It covers the status and trends of the natural world, the impact of these trends on societies, their causes and the potential actions that can be taken to address some of the negative trends observed.

    2. What are the services provided by Nature?

      The term « Nature » means different things for different people, it is a concept that includes biodiversity, ecosystems, Mother Earth, systems of life and other analogous ideas. Nature’s contributions to people encompass a variety of things, such as ecosystem goods and services and nature’s gifts. Both are vital for human existence and good quality of life.

      Nature, through its ecological and evolutionary processes, sustains the quality of the air, water and soils on which humanity depend; it distributes fresh water, regulates the climate, provides pollination and pest control and reduces the impact of natural hazards. Nature underpins all dimensions of human health and contributes to non-material aspects – inspiration and learning, physical and psychological experiences, and supporting identities – that are central to quality of life and cultural integrity, even if their aggregated value is difficult to quantify.

      While more food, energy and materials than ever before are now being supplied to people in most places, this is increasingly at the expense of nature’s ability to provide such contributions in the future and frequently undermines nature’s many other contributions, which range from water quality regulation to a sense of place.

      3. How important are Nature’s contribution to human existence?

        Most of nature’s contributions to people are not fully replaceable and some are even irreplaceable. Nature plays a critical role in providing food and feed, energy, medicines and genetic resources and a variety of materials fundamental for people’s physical well-being and for maintaining culture. For example, more than 2 billion people rely on wood fuel to meet their primary energy needs, an estimated 4 billion people rely primarily on natural medicines for their health care and some 70 per cent of drugs used for cancer are natural or are synthetic products inspired by nature.

        Many of these Nature’s contributions to human societies are now co-produced with people, but while anthropogenic assets – knowledge and institutions, technology infrastructure and financial capital – can enhance or partially replace some of those contributions, some are irreplaceable. The diversity of Nature also maintains humanity’s ability to choose alternatives in the face of an uncertain future.

        These contributions to people are often distributed unequally across space and time and among different segments of society, and there are often trade-offs in the production and use of nature’s contributions. Giving priority to one of nature’s contributions to people can result in ecological changes that reduce other contributions. For instance, the great expansion in the production of food, feed, fibre and bioenergy has occurred at the cost of many other contributions of nature to quality of life, including regulation of air and water quality, climate regulation and habitat provision. Synergies also exist, such as sustainable agricultural practices that enhance soil quality, thereby improving productivity and other ecosystem functions and services, such as carbon sequestration and water quality regulation.

        4. What are the present trends in Nature’s state and biodiversity?

          Nature and its vital contributions to people are deteriorating worldwide. The biosphere, upon which humanity as a whole depends, is being altered to an unparalleled degree across all spatial scales by multiple human drivers, with the great majority of indicators of ecosystems and biodiversity showing rapid decline. Biodiversity (the diversity within species, between species and of ecosystems) is declining faster than at any time in human history.

          Nature has now been significantly altered by multiple human drivers. About 75 % of the land surface is significantly altered, 66 % of the ocean area is experiencing increasing cumulative impacts, and over 85 % of wetlands (area) has been lost.

          Exctinction since 1500 / Declines in species survival 1980 ( Red List Index)

          Human actions threaten more species with global extinction now than ever before. An average of around 25 per cent of species in assessed animal and plant groups are threatened, suggesting that around 1 million species already face extinction, many within decades, unless action is taken. Without such action, there will be a further acceleration in the global rate of species extinction, which is already at least tens to hundreds of times higher than it has averaged over the past 10 million years

          Since 1970, trends in agricultural production, fish harvest, bioenergy production and harvest of materials have increased, but 14 of the 18 categories of contributions of nature that were assessed, mostly regulating and non-material contributions, have declined. The average abundance of native species in most major terrestrial biomes has fallen and native biodiversity has often been severely impacted by invasive alien species.

          While the rate of forest loss has slowed globally since 2000, this is distributed unequally. Across much of the highly biodiverse tropics, 32 million hectares of primary or recovering forest were lost between 2010 and 2015. Approximately half the live coral cover on coral reefs has been lost since the 1870s, with accelerating losses in recent decades due to climate change exacerbating other drivers. Globally, local varieties and breeds of domesticated plants and animals are disappearing. This loss of diversity, including genetic diversity, poses a serious risk to global food security by undermining the resilience of many agricultural systems to threats such as pests, pathogens and climate change.

          Biological communities are becoming more similar to each other in both managed and unmanaged systems within and across regions. This human-caused process leads to losses of local biodiversity, including endemic species, ecosystem functions and nature’s contributions to people . Human-induced changes are creating conditions for fast biological evolution that can create uncertainty about the sustainability of species, ecosystem functions and the delivery of nature’s contributions to people. Without action, there will be a further acceleration in the global rate of species extinction.

          5. What are the elements that have driven changes in the past 50 years?

            In the past 50 years, the human population has doubled, the global economy has grown nearly fourfold and global trade has grown tenfold, together driving up the demand for energy and materials. A variety of economic, political and social factors have shifted the economic and environmental gains and losses of production and consumption, contributing to new economic opportunities, but also to impacts on nature and its contributions to people. These direct and indirect drivers of change in Nature have accelerated and are unprecedented in human history. The direct drivers of change with the largest global impact have been (in order of importance for their impact):

            1. Changes in land and sea use;
            2. Direct exploitation of organisms, in particular overexploitation of animals, plants and other organisms, mainly via harvesting, logging, hunting and fishing;
            3. Climate change;
            4. Pollution;
            5. Invasion of alien species.

            Those five direct drivers result from an array of indirect underlying causes which are in turn underpinned by societal values and behaviours that include production and consumption patterns, human population dynamics and trends, trade, technological innovations and local through global governance. The rate of change in these direct and indirect drivers differs among regions and countries.

            Many types of pollution, as well as invasive alien species, are increasing, with negative impacts for nature. Although global trends are mixed, air, water and soil pollution have continued to increase in some areas. Marine plastic pollution in particular has increased tenfold since 1980.

            The compounding effects of these drivers are likely to exacerbate the negative impacts on Nature, as seen in different ecosystems including coral reefs, the Arctic systems and savannas. Climate change in particular is a direct driver that is increasingly exacerbating the impact of other drivers on nature and human well-being. Humans are estimated to have caused an observed warming of approximately 1.0°C by 2017 relative to pre-industrial levels. The changes to the climate have contributed to widespread impacts in many aspects of biodiversity, including species distribution, phenology, population dynamics, community structure and ecosystem function. According to observational evidence, the effects are accelerating in marine, terrestrial and freshwater ecosystems and are already impacting agriculture, aquaculture, fisheries and nature’s contributions to people.

            Economic incentives have generally favoured expanding economic activity, and often environmental harm, over conservation or restoration. Incorporating in the economy the consideration of the multiple values of ecosystem functions and of nature’s contributions to people into economic incentives has been shown to permit better ecological, economic and social outcomes.

            Nature managed by indigenous peoples and local communities is under increasing pressure. Nature is generally declining less rapidly in indigenous peoples’ land than in other lands, but is nevertheless declining, as is the knowledge of how to manage it. Recognizing the knowledge, innovations, practices, institutions and values of indigenous peoples and local communities and ensuring their inclusion and participation in environmental governance, often enhances their quality of life and the conservation, restoration and sustainable use of nature, which is relevant to broader society.

            The negative trends in biodiversity and ecosystem functions are projected to continue or worsen in many future scenarios in response to indirect drivers such as rapid human population growth, unsustainable production and consumption and associated technological development.

            6. What are the consequences for the services to human existence provided by Nature?

              Countries at different levels of development have experienced different levels of deterioration of nature for any given gain in economic growth. Exclusion, scarcity and/or the unequal distribution of nature’s contributions to people may fuel social instability and conflict in a complex interaction with other factors. Armed conflicts have an impact on ecosystems beyond their destabilizing effects on societies, and a range of indirect impacts, including the displacement of people and activities.

              Past and ongoing rapid declines in biodiversity, ecosystem functions and many of nature’s contributions to people mean that most international societal and environmental goals, such as those embodied in the Aichi Biodiversity Targets and the 2030 Agenda for Sustainable Development, will not be achieved based on current trajectories. These declines will also undermine other goals, such as those specified in the Paris Agreement adopted under the United Nations Framework Convention on Climate Change and the 2050 Vision for Biodiversity.

              While achieving the Sustainable Development Goals (SDGs) is essential for Nature, taking into consideration that these SDGs are indivisible and should be nationally implemented, the current negative trends in biodiversity and ecosystems will undermine progress towards 80 % of the assessed targets of Goals (35 out of the 44) related to poverty, hunger, health, water, cities, climate, oceans and land.

              Although important positive synergies between Nature and the SDGs related to education, gender equality, reducing inequalities and promoting peace and justice were found, the current focus and wording of their targets obscure or omit their relationship to Nature, thereby preventing their adequate assessment in this field.

              7. What goals and objectives in the way things are done should be set for 2030 and beyond to conserve Nature while still benefiting from it?

                As by current trajectories, goals for 2030 and beyond for conserving and sustainably using Nature and achieving sustainability cannot be met. These may only be achieved through transformative changes across economic, social, political and technological factors.

                Societal goals, including those related to food, water, energy, health and the achievement of human well-being for all, mitigating and adapting to climate change and conserving and sustainably using nature, can be achieved in sustainable pathways through the rapid and improved deployment of existing policy instruments and new initiatives that more effectively enlist individual and collective actions for transformative changes.

                A key component of sustainable pathways is the evolution of global financial and economic systems to build a global sustainable economy, steering away from the current, limited paradigm of economic growth. This implies incorporating the reduction of inequalities into development pathways, reducing overconsumption and waste and addressing environmental impacts, such as externalities of economic activities, from the local to the global scales.

                Feeding humanity and enhancing the conservation and sustainable use of nature are complementary and closely interdependent goals that can be advanced through sustainable agriculture, aquaculture and livestock systems, the safeguarding of native species, varieties, breeds and habitats, and ecological restoration. Sustaining and conserving fisheries and marine species and ecosystems can be achieved through a coordinated mix of interventions on land, in freshwater and in the oceans, including multilevel coordination across stakeholders on the use of open oceans.

                Nature-based solutions can be cost-effective for meeting the Sustainable Development Goals in cities, which are crucial for global sustainability. Increased use of green infrastructure and other ecosystem- based approaches can help advance sustainable urban development while reinforcing climate mitigation and adaptation. The achievement of these societal and environmental objectives depends thus on new scenarios and pathways that explore the effects of low-to-moderate population growth, and transformative changes in the production and consumption of energy, food, feed, fibre and water, sustainable use, equitable sharing of the benefits arising from use, and nature-friendly climate adaptation and mitigation.

                Such scenarios show that meeting the SDGs and the 2050 Vision for Biodiversity depends in particular on taking into account climate change impacts in the definition of future goals and objectives. Land-based climate change mitigation activities can be effective and support conservation goals. However, the large-scale deployment of bioenergy plantations and afforestation of non-forest ecosystems can come with negative side effects for biodiversity and ecosystem functions.

                8. What are the main obstacles in meeting these sustainability goals regarding in particular the biodiversity challenges?

                  By its very nature, transformative change can expect opposition from those with interests vested in the status quo, but such opposition can be overcome for the broader public good. If obstacles are overcome, a commitment to mutually supportive international goals and targets, supporting actions by indigenous peoples and local communities at the local level, new frameworks for private sector investment and innovation, inclusive and adaptive governance approaches and arrangements, multi-sectoral planning, and strategic policy mixes, can altogether help transform the public and private sectors to achieve sustainability at the local, national and global levels.

                  The character and trajectories of transformation will vary across contexts, with challenges and needs differing, among others, in developing and developed countries. Risks related to the inevitable uncertainties and complexities in transformations towards sustainability can be reduced through governance approaches that are integrative, inclusive, informed and adaptive.

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