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Global biodiversity outlook 31

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Species populations and extinction risks 14

Terrestrial ecosystems 17

Inland waters ecosystems 27

Marine and coastal ecosystems 30

Genetic diversity 36

Current pressures on biodiversity and responses 38


Terrestrial ecosystems 53

Inland water ecosystems 55

Coastal and marine ecosystems 56




    The target agreed by the world’s Governments in 2002, “to achieve by 2010 a significant reduction of the current rate of biodiversity loss at the global, regional and national level as a contribution to poverty alleviation and to the benefit of all life on Earth”, has not been met. There are multiple indications of continuing decline in biodiversity in all three of its main components — genes, species and ecosystems — including:

  • Species which have been assessed for extinction risk are on average moving closer to extinction. Amphibians face the greatest risk and coral species are deteriorating most rapidly in status. Nearly a quarter of plant species are estimated to be threatened with extinction.

  • The abundance of vertebrate species, based on assessed populations, fell by nearly a third on average between 1970 and 2006, and continues to fall globally, with especially severe declines in the tropics and among freshwater species.

  • Natural habitats in most parts of the world continue to decline in extent and integrity, although there has been significant progress in slowing the rate of loss for tropical forests and mangroves, in some regions. Freshwater wetlands, sea ice habitats, salt marshes, coral reefs, seagrass beds and shellfish reefs are all showing serious declines.

  • Extensive fragmentation and degradation of forests, rivers and other ecosystems have also led to loss of biodiversity and ecosystem services.

  • Crop and livestock genetic diversity continues to decline in agricultural systems.

  • The five principal pressures directly driving biodiversity loss (habitat change, overexploitation, pollution, invasive alien species and climate change) are either constant or increasing in intensity.

  • The ecological footprint of humanity exceeds the biological capacity of the Earth by a wider margin than at the time the 2010 target was agreed.

    The loss of biodiversity is an issue of profound concern for its own sake. Biodiversity also underpins the functioning of ecosystems which provide a wide range of services to human societies. Its continued loss, therefore, has major implications for current and future human well-being. The provision of food, fibre, medicines and fresh water, pollination of crops, filtration of pollutants, and protection from natural disasters are among those ecosystem services potentially threatened by declines and changes in biodiversity. Cultural services such as spiritual and religious values, opportunities for knowledge and education, as well as recreational and aesthetic values, are also declining.

    The existence of the 2010 biodiversity target has helped to stimulate important action to safeguard biodiversity, such as creating more protected areas (on both land and in coastal waters), the conservation of particular species, and initiatives to tackle some of the direct causes of ecosystem damage, such as pollution and alien species invasions. Some 170 countries now have national biodiversity strategies and action plans. At the international level, financial resources have been mobilized and progress has been made in developing mechanisms for research, monitoring and scientific assessment of biodiversity.

    Many actions in support of biodiversity have had significant and measurable results in particular areas and amongst targeted species and ecosystems. This suggests that with adequate resources and political will, the tools exist for loss of biodiversity to be reduced at wider scales. For example, recent government policies to curb deforestation have been followed by declining rates of forest loss in some tropical countries. Measures to control alien invasive species have helped a number of species to move to a lower extinction risk category. It has been estimated that at least 31 bird species (out of 9,800) would have become extinct in the past century, in the absence of conservation measures. 

    However, action to implement the Convention on Biological Diversity has not been taken on a sufficient scale to address the pressures on biodiversity in most places. There has been insufficient integration of biodiversity issues into broader policies, strategies and programmes, and the underlying drivers of biodiversity loss have not been addressed significantly. Actions to promote the conservation and sustainable use of biodiversity receive a tiny fraction of funding compared to activities aimed at promoting infrastructure and industrial developments. Moreover, biodiversity considerations are often ignored when such developments are designed, and opportunities to plan in ways that minimize unnecessary negative impacts on biodiversity are missed. Actions to address the underlying drivers of biodiversity loss, including demographic, economic, technological, socio-political and cultural pressures, in meaningful ways, have also been limited.

    Most future scenarios project continuing high levels of extinctions and loss of habitats throughout this century, with associated decline of some ecosystem services important to human well-being. For example:

  • Tropical forests would continue to be cleared in favour of crops and pastures, and potentially for biofuel production.

  • Climate change, the introduction of invasive alien species, pollution and dam construction would put further pressure on freshwater biodiversity and the services it underpins.

  • Overfishing would continue to damage marine ecosystems and cause the collapse of fish populations, leading to the failure of fisheries.

    Changes in the abundance and distribution of species may have serious consequences for human societies. The geographical distribution of species and vegetation types is projected to shift radically due to climate change, with ranges moving from hundreds to thousands of kilometres towards the poles by the end of the 21st century. Migration of marine species to cooler waters could make tropical oceans less diverse, while both boreal and temperate forests face widespread dieback at the southern end of their existing ranges, with impacts on fisheries, wood harvests, recreation opportunities and other services.

    There is a high risk of dramatic biodiversity loss and accompanying degradation of a broad range of ecosystem services if ecosystems are pushed beyond certain thresholds or tipping points. The poor would face the earliest and most severe impacts of such changes, but ultimately all societies and communities would suffer. Examples include:

  • The Amazon forest, due to the interaction of deforestation, fire and climate change, could undergo a widespread dieback, with parts of the forest moving into a self-perpetuating cycle of more frequent fires and intense droughts leading to a shift to savanna-like vegetation. While there are large uncertainties associated with these scenarios, it is known that such dieback becomes much more likely to occur if deforestation exceeds 20 – 30% (it is currently above 17% in the Brazilian Amazon). It would lead to regional rainfall reductions, compromising agricultural production. There would also be global impacts through increased carbon emissions, and massive loss of biodiversity.

  • The build-up of phosphates and nitrates from agricultural fertilizers and sewage effluent can shift freshwater lakes and other inland water ecosystems into a long-term, algae-dominated (eutrophic) state. This could lead to declining fish availability with implications for food security in many developing countries. There will also be loss of recreation opportunities and tourism income, and in some cases health risks for people and livestock from toxic algal blooms. Similar, nitrogen–induced eutrophication phenomena in coastal environments lead to more oxygen-starved dead zones, with major economic losses resulting from reduced productivity of fisheries and decreased tourism revenues.

  • The combined impacts of ocean acidification, warmer sea temperatures and other human-induced stresses make tropical coral reef ecosystems vulnerable to collapse. More acidic water — brought about by higher carbon dioxide concentrations in the atmosphere —decreases the availability of the carbonate ions required to build coral skeletons. Together with the bleaching impact of warmer water, elevated nutrient levels from pollution, overfishing, sediment deposition arising from inland deforestation, and other pressures, reefs worldwide increasingly become algae-dominated with catastrophic loss of biodiversity and ecosystem functioning, threatening the livelihoods and food security of hundreds of millions of people.

    There are greater opportunities than previously recognized to address the biodiversity crisis while contributing to other social objectives. For example, analyses conducted for this Outlook identified scenarios in which climate change is mitigated while maintaining and even expanding the current extent of forests and other natural ecosystems (avoiding additional habitat loss from the widespread deployment of biofuels). Other opportunities include “rewilding” abandoned farmland in some regions, and the restoration of river basins and other wetland ecosystems to enhance water supply, flood control and the removal of pollutants.

    Well-targeted policies focusing on critical areas, species and ecosystem services are essential to avoid the most dangerous impacts on people and societies. Preventing further human-induced biodiversity loss for the near-term future will be extremely challenging, but biodiversity loss may be halted and in some aspects reversed in the longer term, if urgent, concerted and effective action is initiated now in support of an agreed long-term vision. Such action to conserve biodiversity and use its components sustainably will reap rich rewards - through better health, greater food security, less poverty and a greater capacity to cope with, and adapt to, environmental change.

    Placing greater priority on biodiversity is central to the success of development and poverty-alleviation measures. It is clear that continuing with “business as usual” will jeopardize the future of all human societies, and none more so than the poorest who depend directly on biodiversity for a particularly high proportion of their basic needs. The loss of biodiversity is frequently linked to the loss of cultural diversity, and has an especially high negative impact on indigenous communities.

    The linked challenges of biodiversity loss and climate change must be addressed by policymakers with equal priority and in close co-ordination, if the most severe impacts of each are to be avoided. Reducing the further loss of carbon-storing ecosystems such as tropical forests, salt marshes and peatlands will be a crucial step in limiting the build-up of greenhouse gases in the atmosphere. At the same time, reducing other pressures on ecosystems can increase their resilience, make them less vulnerable to those impacts of climate change which are already unavoidable, and allow them to continue to provide services to support people’s livelihoods and help them adapt to climate change.

    Better protection of biodiversity should be seen as a prudent and cost-effective investment in risk-avoidance for the global community. The consequences of abrupt ecosystem changes on a large scale affect human security to such an extent, that it is rational to minimize the risk of triggering them - even if we are not clear about the precise probability that they will occur. Ecosystem degradation, and the consequent loss of ecosystem services, has been identified as one of the main sources of disaster risk. Investment in resilient and diverse ecosystems, able to withstand the multiple pressures they are subjected to, may be the best-value insurance policy yet devised.

    Scientific uncertainty surrounding the precise connections between biodiversity and human well-being, and the functioning of ecosystems, should not be used as an excuse for inaction. No one can predict with accuracy how close we are to ecosystem tipping points, and how much additional pressure might bring them about. What is known from past examples, however, is that once an ecosystem shifts to another state, it can be difficult or impossible to return it to the former conditions on which economies and patterns of settlement have been built for generations.

    Effective action to address biodiversity loss depends on addressing the underlying causes or indirect drivers of that decline. This will mean:

  • Much greater efficiency in the use of land, energy, fresh water and materials to meet growing demand.

  • Use of market incentives, and avoidance of perverse subsidies to minimize unsustainable resource use and wasteful consumption.

  • Strategic planning in the use of land, inland waters and marine resources to reconcile development with conservation of biodiversity and the maintenance of multiple ecosystem services. While some actions may entail moderate costs or tradeoffs, the gains for biodiversity can be large in comparison.

  • Ensuring that the benefits arising from use of and access to genetic resources and associated traditional knowledge, for example through the development of drugs and cosmetics, are equitably shared with the countries and cultures from which they are obtained.

  • Communication, education and awareness-raising to ensure that as far as possible, everyone understands the value of biodiversity and what steps they can take to protect it, including through changes in personal consumption and behaviour.

    The real benefits of biodiversity, and the costs of its loss, need to be reflected within economic systems and markets. Perverse subsidies and the lack of economic value attached to the huge benefits provided by ecosystems have contributed to the loss of biodiversity. Through regulation and other measures, markets can and must be harnessed to create incentives to safeguard and strengthen, rather than to deplete, our natural infrastructure. The re-structuring of economies and financial systems following the global recession provides an opportunity for such changes to be made. Early action will be both more effective and less costly than inaction or delayed action.

    Urgent action is needed to reduce the direct drivers of biodiversity loss. The application of best practices in agriculture, sustainable forest management and sustainable fisheries should become standard practice, and approaches aimed at optimizing multiple ecosystem services instead of maximizing a single one should be promoted. In many cases, multiple drivers are combining to cause biodiversity loss and degradation of ecosystems. Sometimes, it may be more effective to concentrate urgent action on reducing those drivers most responsive to policy changes. This will reduce the pressures on biodiversity and protect its value for human societies in the short to medium-term, while the more intractable drivers are addressed over a longer time-scale. For example the resilience of coral reefs – and their ability to withstand and adapt to coral bleaching and ocean acidification – can be enhanced by reducing overfishing, land-based pollution and physical damage.

    Direct action to conserve biodiversity must be continued, targeting vulnerable as well as culturally-valued species and ecosystems, combined with steps to safeguard key ecosystem services, particularly those of importance to the poor. Activities could focus on the conservation of species threatened with extinction, those harvested for commercial purposes, or species of cultural significance. They should also ensure the protection of functional ecological groups – that is, groups of species that collectively perform particular, essential roles within ecosystems, such as pollination, control of herbivore numbers by top predators, cycling of nutrients and soil formation.

    Increasingly, restoration of terrestrial, inland water and marine ecosystems will be needed to re-establish ecosystem functioning and the provision of valuable services. Economic analysis shows that ecosystem restoration can give good economic rates of return. However the biodiversity and associated services of restored ecosystems usually remain below the levels of natural ecosystems. This reinforces the argument that, where possible, avoiding degradation through conservation is preferable (and even more cost-effective) than restoration after the event.

    Better decisions for biodiversity must be made at all levels and in all sectors, in particular the major economic sectors, and government has a key enabling role to play. National programmes or legislation can be crucial in creating a favourable environment to support effective “bottom-up” initiatives led by communities, local authorities, or businesses. This also includes empowering indigenous peoples and local communities to take responsibility for biodiversity management and decision-making; and developing systems to ensure that the benefits arising from access to genetic resources are equitably shared.

    We can no longer see the continued loss of and changes to biodiversity as an issue separate from the core concerns of society: to tackle poverty, to improve the health, prosperity and security of our populations, and to deal with climate change. Each of those objectives is undermined by current trends in the state of our ecosystems, and each will be greatly strengthened if we correctly value the role of biodiversity in supporting the shared priorities of the international community. Achieving this will involve placing biodiversity in the mainstream of decision-making in government, the private sector, and other institutions from the local to international scales.

    The action taken over the next decade or two, and the direction charted under the Convention on Biological Diversity, will determine whether the relatively stable environmental conditions on which human civilization has depended for the past 10,000 years will continue beyond this century. If we fail to use this opportunity, many ecosystems on the planet will move into new, unprecedented states in which the capacity to provide for the needs of present and future generations is highly uncertain.


This Outlook presents some stark choices for human societies. On one hand it warns that the diversity of living things on the planet continues to be eroded as a result of human activities. The pressures driving the loss of biodiversity show few signs of easing, and in some cases are escalating. The consequences of current trends are much worse than previously thought2, and place in doubt the continued provision of vital ecosystem services.3 The poor stand to suffer disproportionately from potentially catastrophic changes to ecosystems in coming decades, but ultimately all societies stand to lose.

On the other hand, the Outlook offers a message of hope. The options for addressing the crisis are wider than was apparent in earlier studies. Determined action to conserve biodiversity and use it sustainably will reap rich rewards. It will benefit people in many ways - through better health, greater food security and less poverty. It will safeguard the variety of nature, an objective justified in its own right according to a range of belief systems and moral codes. It will help to slow climate change by enabling ecosystems to absorb and store more carbon; and it will help people adapt to climate change by adding resilience to ecosystems and making them less vulnerable.
Taking actions to ensure the maintenance and restoration of well-functioning ecosystems, underpinned by biodiversity and providing natural infrastructure for human societies, can provide economic gains worth trillions of dollars a year4. The latest science suggests ever more strongly that better management, conservation and sustainable use of biodiversity is a prudent and cost-effective investment in social and economic security, and in risk reduction for the global community5.
This Outlook shows that efforts to date have not been sufficient to reduce significantly the rate of biodiversity loss and analyses why; it assesses the potential for long-lasting or irreversible ecosystem changes to result from current trends and practices; and it concludes that concerted and targeted responses, with action applied at appropriate levels to address both direct pressures on biodiversity and their underlying causes, can in the long term stop or even reverse the continued decline in the variety of life on Earth.
The action taken over the next two decades will determine whether the relatively stable environmental conditions on which human civilization has depended for the past 10,000 years will continue beyond this century.6 If we fail to use this opportunity, many ecosystems on the planet will move into new, unprecedented states in which the capacity to provide for the needs of present and future generations is highly uncertain.

Box 1: Biodiversity, the CBD and the 2010 target
The word biodiversity, a contraction of the synonymous phrase ‘biological diversity’, is defined by the Convention on Biological Diversity (CBD) as ‘the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems’7. This is the definition used throughout this document.
The CBD is one of the three “Rio Conventions”, emerging from the UN Conference on Environment and Development, also known as the Earth Summit, held in Rio de Janeiro in 1992. It came into force at the end of 1993, with the following objectives:
“The conservation of biological diversity, the sustainable use of its components and the fair and equitable sharing of the benefits arising out of the utilization of genetic resources, including by appropriate access to genetic resources and by appropriate transfer of relevant technologies, taking into account all rights over those resources and to technologies, and by appropriate funding.”8
There are currently 193 Parties to the Convention (192 countries and the European Union)9. In April 2002, the Parties to the Convention committed themselves to achieve by 2010 a significant reduction of the current rate of biodiversity loss at the global, regional and national level as a contribution to poverty alleviation and to the benefit of all life on Earth10. This target was subsequently endorsed by the World Summit on Sustainable Development (the “Rio + 10” summit) in Johannesburg, 2002, and by the United Nations General Assembly. It was also incorporated as a new target under one of the Millennium Development Goals – Ensure Environmental Sustainability. The 2010 biodiversity target is therefore a commitment from all governments, including those not party to the CBD.
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