Hugh Possingham and David PannellARC Laureate Fellows
The University of Queensland and The University of Western AustraliaNational 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’s Curve (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
Environmental Kuznets Curve
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 likeN
umbe
r of s
peci
es
Time/per capita income
EKC really affects habitat loss rateRa
te o
f hab
itat l
oss,
dH/
dt
Time/per capita income
Habitat loss rate affects habitatAm
ount
of h
abita
t, H
Time/per capita income
?
Habitat affects species loss rateRa
te o
f spe
cies
loss
, dS/
dt
Time/per capita income
Species loss rate affects speciesN
umbe
r of s
peci
es, 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 loss1. Australia must invest in biodiversity proportionate to its value.2. Biodiversity conservation efforts need to be better prioritized with respect to both
space and type of action. 3. 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.4. Strategic large-scale restoration of parts of southern Australia could reduce a huge
“extinction debt” – one important action that is not preventative.5. It is time to complete the National Reserve System (NRS) and manage those
reserves we have better.6. Australia must invest in long-term monitoring of cleverly chosen aspects of
biodiversity and honestly report on how it changes.7. Natural resource managers need better training and resources.8. Conservationists are too conservative: they must embrace new landscapes and
radical ideas (such as the importance of novel ecosystems).9. State and regional bodies need to take a more experimental approach to whole of
landscape management. 10. 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.
Keep up with the EDG: www.decision-point.com.au
Subscribe today
It’s free!
