These attempts to downplay the biodiversity crisis follow the ‘Scientific Certainty Argumentation Methods’ playbook, which includes all three categories of denial envisioned by Stanley Cohen in a framework first applied to the study of atrocities and other unwelcome truths4. These are: (1) ‘Literal denial’, an assertion that something is untrue, for example the evidence for greatly elevated rates of species threat and extinction; (2) ‘Interpretive denial’, in which raw facts are not disputed but given a different spin, for example using evidence from temperate ecosystems to make claims about reduced impacts in the tropics; (3) ‘Implicatory denial’, in which data are not denied, but implications are, for example arguing that transformative changes to socio–ecological systems are not required to avert species extinctions.
We address each of these in detail, before exploring ways to counter erroneous claims and logical fallacies that we understand to be ‘extinction denialism’ or ‘biodiversity loss denialism’.
Literal denial: ‘Species extinctions were predominantly a historical problem’
Extinction deniers often downplay the extinction crisis by framing it as a historical problem and a trivial contemporary challenge (Supplementary Table 1). By focusing attention on the loss of megafauna in prehistory owing to overhunting and rapid loss of island biodiversity in historic times, it is suggested we have passed through these extinction filters and reached the ‘other side’ of the crisis. This ‘literal denial’ line of argument misses several key facets of the extinction crisis, notably that species, including island endemics, are still being lost5 and that the catastrophic loss, degradation and fragmentation of whole ecosystems, combined with climate change, is triggering a new episode of continental extinctions6. This is particularly acute in the highly biodiverse tropics and where extinctions are just the endpoint of a long process of extirpation and defaunation7 (Box 1, Supplementary Table 2). Moreover, biologists are typically conservative in declaring possible extinctions, and across the world there are 143 amphibians, 41 reptiles, 29 mammals and 22 bird species classed by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species (https://www.iucnredlist.org) as ‘Critically Endangered (Possibly Extinct)’. Many of these species are likely already gone, while many more, including the 75 species listed as ‘Extinct in the Wild’, are only hanging on due to expensive, last resort, conservation interventions8.
Interpretive denial: ‘Economic growth alone will fix the extinction crisis’
Extinction denialists often invoke an Environmental Kuznets Curve (EKC)9 response of biodiversity to development (Supplementary Table 1), arguing that pressures on the environment eventually decrease with rising income levels. Yet the EKC hypothesis is misleading in this context. First, empirical evidence of the relationship between economic development and forest cover only supports the loss part of the curve10. Second, the EKC is typically a local rather than a global phenomenon, and global environmental indicators of indirect impacts such as CO2 emissions, waste production and energy consumption are still increasing monotonically. Country-specific assessments of EKC often ignore the outsourcing of environmental degradation to poorer countries. Denialists also highlight the resurgence of certain large charismatic species such as wolves and bears in Europe and North America as evidence that we are through the worst of the extinction crisis. However, this is only a partial success story (Box 1). Similar successes in the tropics are highly unlikely: species richness, species packing and habitat and niche specialization are all far higher at tropical latitudes, while geographic range sizes are much smaller. These factors mean that tropical biodiversity is far more extinction-prone then temperate biodiversity11. The unfortunate truth is that there are many imminent or actual extinctions in highly deforested tropical regions (Supplementary Table 2). Finally, the so-called ‘Forest Transition’ model9, which envisages an EKC-style relationship between forest cover and development, fails to differentiate between native forests and monoculture plantations of oil palm, conifers and eucalyptus, despite the expansion of plantations being an important cause of biodiversity loss. Many global forest models are not sensitive to the difference12 and conflating plantations with natural forests has long been a key feature of the denialist playbook.
Implicatory denial: ‘Technological fixes and targeted conservation interventions will overcome extinction’
Extinction denialists are often selective, choosing to highlight only a subset of factors causing contemporary extinctions, such as overharvesting and predation by non-native species, while choosing not to mention habitat loss that affects the majority of species on the Red List. They then suggest that solutions are simple, requiring no change or business-as-usual actions, even though it is increasing resource demands and current socio–ecological and economic modes of organization that imperil biodiversity globally7. Invasive species, overharvesting and pathogens are undoubtedly major conservation issues responsible for global extinctions of many — particularly insular — species, and technological fixes form part of the portfolio of conservation interventions. However, these threats are often exacerbated by habitat loss and climate change, and all must be addressed together. A disproportionate focus on a subset of drivers is a form of implicatory denial that is contrary to scientific consensus: recognizing the importance of one set of threats does not obviate the need to address others8. Another form of implicatory denial involves the misrepresentation of the land sharing/sparing concept (Box 1).
Source: Ecology - nature.com
