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Hugh Possingham and David Pannell ARC Laureate Fellows The University of Queensland and The University of Western Australia National Environmental Research Program hub for Environmental Decisions http://www.nerpdecisions.edu.au/
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Hugh Possingham and David Pannell ARC Laureate Fellows The University of Queensland and The University of Western Australia National Environmental Research Program hub for Environmental Decisions http://www.nerpdecisions.edu.au/ Australian Research Council Centre of Excellence for Environmental Decisions http://ceed.edu.au/ Biodiversity, People and the Environmental Kuznet’s Curve
Plan • How does population growth and resource use affect biodiversity? • It is OK – the Environmental Kuznet’sCurve (EKC) • Why doesn’t the EKC work for biodiversity? A theory – David says nobody knows • So what can we do?
Impacts of population/resource use on biodiversity • Impacts are innumerable and obvious • Not so obvious – more numerous than you think • Just the presence of people (Reed and Merenlender, 2008) • Other diffuse and in-direct effects, dust, light, noise … • Fossil fuel and marine reserves
Environmental Kuznets Curve • The hypothesis • As national income rises over time, things initially get worse for the environment • Later on it gets better when income high enough • Mechanism • Increasing use of resources • Priority given to increasing wealth • With wealth comes increased demand for environ. goods • Also increasing technical capacity to provide them (i.e. reduced cost of providing them) • Implication: growth good for the environment
Evidence • Over 100 peer-reviewed EKC publications • EKC seems to apply best for local air pollutants such as NOx, SO2, and particulate matter • Evidence for water pollution is mixed – best for biological oxygen demand (BOD), chemical oxygen demand (COD), nitrates, and some heavy metals (arsenic and cadmium) • No evidence of EKC for biodiversity – a number of studies have looked and failed to find the effect • Why not? (asks David Pannell September 2013) • Fantasy island for advocates of unrestrained growth (of any kind)
What EKC for biodiversity should look like Number of species Time/per capita income
EKC really affects habitat loss rate Rate of habitat loss, dH/dt Time/per capita income
Habitat loss rate affects habitat Amount of habitat, H ? Time/per capita income
Habitat affects species loss rate Rate of species loss, dS/dt Time/per capita income
Species loss rate affects species Number of species, S Time/per capita income
EKC fails because • Per capita income affects habitat loss rate, not species • The rate of species loss is affected, after a significant delay, by amount of habitat (not rate of habitat loss) • Species loss is irreversible under any reasonable time frame • At best, EKC could work for rate of loss – with delay
So what is the solution to species loss • Australia must invest in biodiversity proportionate to its value. • Biodiversity conservation efforts need to be better prioritized with respect to both space and type of action. • Prevention is better than cure – most of the cost-efficient actions we can take are to stop doing things that cause biodiversity loss rather than curing past mistakes. • Strategic large-scale restoration of parts of southern Australia could reduce a huge “extinction debt” – one important action that is not preventative. • It is time to complete the National Reserve System (NRS) and manage those reserves we have better. • Australia must invest in long-term monitoring of cleverly chosen aspects of biodiversity and honestly report on how it changes. • Natural resource managers need better training and resources. • Conservationists are too conservative: they must embrace new landscapes and radical ideas (such as the importance of novel ecosystems). • State and regional bodies need to take a more experimental approach to whole of landscape management. • It is critical to avoid implementing retrogressive anto-environment and anti-science based policies on biodiversity and environmental management. National and State policy needs to account better for existing science and knowledge.
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