Biodiversity is in crisis. There is well-established evidence indicating an irrevocable and continuing decline of genetic and species diversity, and degradation of ecosystems at local and global scales. Scientists are increasingly concerned that, if anthropogenic pressures on Biodiversity continue unabated, we risk precipitating a sixth mass extinction event in Earth history, with profound impacts on human health and equity. 6.1 ▸
Biodiversity provides many valuable goods and services – nature’s contributions to people (well established). Biodiversity helps regulate climate through carbon storage and control of local rainfall, filters air and water, and mitigates the impact of natural disasters such as landslides and coastal storms. Direct benefits include timber from forests, fish from oceans and freshwater systems, crops and medicines from plants, cultural identity, and the health benefits gained from access to nature. 6.1 ▸
Biodiversity loss has consequences for human health and equity (well established). Biodiversity contributes positively to human health and well-being. The livelihoods of more than 70 per cent of the world’s population living in poverty depend on natural resources to some extent and over 80 per cent of global biodiversity is found in the traditional territories of indigenous peoples. Depleting this natural capital will therefore disproportionately affect the people least able to offset losses and reduce options for future generations. 6.1 ▸
The loss of biodiversity reduces ecosystem resilience and increases vulnerability to threats including negative impacts of climate change (well established). At local scales, it is likely that ecosystems with greater biodiversity are more productive and more stable through time. {6.5.4} {6.5.6}
The critical pressures on Biodiversity are well recognized (well established). Biodiversity is being eroded by land-use change, direct exploitation, climate change, pollution and invasive alien species. While habitat loss and transformation is likely the most significant present pressure, climate change may be the most significant future pressure. 6.3 ▸
Pressures often overlap and there are positive feedback loops between many of them (well established). Habitat changes may increase exposure to pollutants, pests, exotic pathogens and emerging infectious diseases harmful to humans, livestock and wildlife, and exacerbate human-wildlife conflicts. Forests are experiencing alteration due to multiple land-use changes such as logging, mining, road building and agricultural expansion; the resulting habitat fragmentation and loss of biodiversity can lower forest resilience to climate change impacts and the introduction of invasive species. {6.3.1}
Newly recognized and aggravating factors add to pressures on biodiversity (well established). Energy production, resource extraction, wildlife trade and poaching, chemical waste and plastics in the marine environment are exacerbating factors that contribute to biodiversity decline. {6.3.1} {6.3.3} {6.3.4}
Genetic diversity is the vital raw material allowing adaptation (well established). The decline in the population size of many species represents a loss in genetic diversity. Genetic diversity of crops, crop wild relatives and livestock provides resilience of agricultural systems to changing environments. The ongoing long-term loss of crop and livestock genetic diversity is a threat to food security. 6.4.1 ▸
There is no slowing in the rate of species population decline globally (well established). The increase in species extinction risks through time is well established, and there is no slowing in the rate of population declines globally. Freshwater species have the highest rates of population declines, whereas amphibians, reef-forming corals and cycads are the taxa with the highest proportion of species currently considered at risk of extinction. There is less data on invertebrate groups, but recent evidence indicates large declines in local abundance. The loss of invertebrate pollinators has been highlighted as a growing problem, with major consequences for agricultural production, ecosystem functioning and human well-being. 6.4.2 ▸
There is no global overview of ecosystem health (well established)., The status of many habitat types is very likely in decline. While global monitoring is challenging, across terrestrial habitats 10 out of 14 have seen a decrease in vegetation productivity, and just under half of all terrestrial ecoregions are classified as having an unfavourable status. Natural wetland areas and marine habitats, such as deep-sea ecosystems and coral reefs, are highlighted as of particular concern globally. 6.4.3 ▸
Biodiversity loss is being experienced across all Earth’s major biomes (well established). In the oceans, overexploitation of fish stocks is leading to fisheries collapse, warming is destroying coral reefs, and habitat destruction of coastal systems, such as mangrove forests, exposes communities to greater risks from erosion and extreme weather events. Marine plastic pollution is a major and growing threat to biodiversity. In freshwater systems, agricultural and chemical pollution, including increased nitrogen input, results in toxic algal blooms and a decline in drinking-water quality; invasive species are spreading through waterways; and freshwater species are declining at a faster rate than those in any other biome. In the terrestrial environment, rising temperatures are converting grasslands into deserts, and unsustainable irrigation has turned drylands into inhospitable, toxic landscapes unsuitable for wildlife or agriculture. Mountain ecosystems and polar regions are especially vulnerable to climate change, and extinctions may be likely for species at the upper limits of their thermal ranges and those dependent on sea ice. Tropical forests represent some of the most biodiverse terrestrial ecosystems, yet deforestation and forest degradation continue in many regions, often in response to demands for wood, fibre, food and fuel products such as palm oil, as well as external drivers. 6.5.1 ▸ 6.5.2 ▸ 6.5.3 ▸ {6.5.4} {6.5.5} {6.5.6} {6.5.7} {6.5.8}
A range of national and international instruments work to conserve biodiversity (well established). These include National Biodiversity Strategies and Actions Plans (NBSAPS) under the Convention on Biological Diversity (CBD), the Strategic Plan for Biodiversity 2011-2020 (encompassing the Aichi targets), the Cartagena Protocol on Biosafety, the Nagoya Protocol, and the Intergovernmental Platform for Biodiversity and Ecosystem Services (IPBES). 6.6.1 ▸ 6.6.2 ▸
Species and ecosystems are most effectively safeguarded through the conservation of natural habitats (well established). There has been significant progress in expanding the global network of protected areas, but the total area under protection remains insufficient, and habitats within protected areas are often degraded. 6.6.3 ▸
Ex-situ conservation of biological material can contribute to conserving genetic diversity (well established). Seed banks and gene banks, aided by the use of these new genomic tools, have contributed to the conservation of the genetic diversity of crops and their wild relatives. Advances in technology allow cheaper and faster genome sequencing, however, genetic data for most wild species are still lacking. 6.4.1 ▸
At a local scale indigenous people and local communities (IPLC) play a key role in protecting biodiversity (well established). IPLCs can offer bottom-up, self-driven, cost-effective and innovative solutions, and have potential to be scaled up and inform national and international practice. Such solutions provide a practical governance approach as an alternative to top-down policy-setting. This is essential to achieve many of the Sustainable Development Goals. {Box 6.6} 6.6.3 ▸
Biodiversity policy responses are visible and operating at international, national and local levels, but they have been insufficient to slow or reverse the decline in global biodiversity (well established). There is an urgent need to bolster current policy responses. There are additional opportunities to maintain biodiversity and the contributions of nature through addressing distribution, access and governance, and by recognizing the role of IPLCs in biodiversity conservation. 6.6.3 ▸ 6.7 ▸
The cost of inaction is large and escalating (well established). The full cost of inaction is rarely quantified; however, failure to act now will impose much higher costs in the future as shown by many examples, such as the spread of invasive species, and extinctions have immeasurable costs for future generations. {6.3.2}
