Biodiversity Week 3

Question 1

Preamble/intro

Rapid materialisation on a global scale features.
(shown in Maddison’s figures)
(3 pos, 1 neg)

Answer 1

Rapid increases in population, life expectancy and GDP from around 1950 onwards holistically across the world.

However also a rapid decline to the environment.

Question 2

3 types of environmental burdens as a result of the rapid materialisation and examples of each

2. What has happened to global vertebrate abundance (animals with backbones)
3. What % of threatened species are impacted by economic activity

Answer 2

Direct exploitation e.g deforestation for timber
Indirect exploitation e.g deforestation for cultivation (farming)
Pollution e.g pollution affects tree health

2. Has fallen, showing a clear loss of habitiat

Question 3

Sustainability concern

Answer 3

Whether economic growth we have seen can be sustained by physical limitation of the planet.

Question 4

3 types of capital: natural produced and human, why is their interaction important??

Natural capital - stocks vs flows

Answer 4

Interaction between human capital, produced capital and natural capital. E.g human capital provides innovation and labour for produced capital, produced capital provides goods/services for human capital.
Important as shows they are all interlinked, so deterioration of one will impact the others. Human and produced capital are dependent on natural capital…Links to sustainability problem… can physical limitation of planet withstand this materialisation

Flow of services we receive from natural capital e.g climate regulation, pollinate crops etc.

Stock of natural capital is the wealth/asset we have

Question 5

What is the economic approach to sustainability?

2.Strong sustainability vs weak and example

Answer 5

Focus on capital rather than flows

2.Strong sustainability- non-decreasing stock of natural capital (leave generation in a no worser state)

Weak- non-decreasing stock of capital

E.g strong may be preserving clean air, weak is just having manufactured capital.

Question 6

2 types of natural capital and why its important to distinguish.

Answer 6

Renewable (regenerative) e.g fish, trees

Non-renewable e.g coal

Both require different analysis:
Hard to value trading off different types of natural capital due to their qualitative characteristics e.g fragmentation, numbers may not matter if geographically separated.

Question 7

What are bioeconomic models

Answer 7

Combine economic and biological features.

Question 8

Fishery graph. Why does it go back down and negative (under the graph?

Answer 8

Growth rate of fish population (s) y axis
Stock of fish x axis

Increases, goes back down due to ecological constraints competition for space, food etc. rate of death faster than birth so growth rates go negative (under the graph)

Question 9

What is MSY and why is it useful, and criticism

Answer 9

Maximum sustainable yield.

The maximum amount of fish you could remove from fishery and leave stock of fish in tact.

Assumes all fish interact and breed, not the case in massive fisheries i.e so big they live independently

Question 10

Fishery diagram 2, explain the points.

Answer 10

Stock is so low it wont replenish. Captures the idea of perhaps fishes living independently and not breeding as not many left so cannot find each other in the fishery

Arrows right of L, and left of S shows a positive growth rate. Stock is growing

An initial condition to the right of S, means growth is negative. (More fish are dying than born, so stock going down) S is point of stable equilibrium, natural dynamics moves back to point S if shocks do occur

Left of L natural dynamics lead to 0, the collapse of species. (It wont come back!)

Question 11

Collapse of North Atlantic cod fishery
Common pool resource
Why free access to fishery was bad
Tragedy of commons

Gordon-schaefer model (static)-TR falls as we fish more. Cost increases linear, constant marginal cost. Monopoly owned operates where MC=MR (MEY). Competitive exploitation operates where AC=AR (BE) like perfect competition.

Question 12

Implications of this diagram

Answer 12

Stability (point S is stable equilibrium-natural dynamics return back to S following shocks)
Thresholds and tipping points (can’t go under L stock otherwise will not recover)
Regime shifts

Question 13

This is just biology, we need to add economics….

Question 14

Most famous collapse of fishery

Answer 14

Collapse of North Atlantic Cod Fishery

Question 15

Why did the fishery collapse

Answer 15

Common pool resource . Tragedy of commons. Overfishing due to free-access. No incentive for individual countries to worry about fish stocks (depleting below L in terms of diagram)

Question 16

Gordon’s-Schaefer model of fishery (static economic model)

Answer 16

TR curve hump sloped as more fish supply so price of fish falls and TR falls. Rev max is at MSY (maximum sustainable yield-max amount of fish that can be fished preserving stock, makes sense to maximise revenue!!)

TC curve linear upwards, no fixed costs and constant fishing cost e.g each boat is same price

Monopoly owned lake operates at MEY (where MC=MR)

Entry (competitive exploitation) continues until TC=TR profits are exhausted

Question 17

Outline the ‘natural capital’ approach to thinking about the sustainability of economic growth. Why has sustainability emerged as an important concern in economic policymaking in the past 30 years?

Answer 17

UN biodiversity conference 2022 focus on protecting biodiversity. So why emerged important? Impacts to economy. Natural capital approach considers value of environment to the economy.

Question 18

2 transitions to slow loss of biodiversity (Q1)

Answer 18

Density urban development to free up land for nature/agriculture.

Make built environments nature positive e.g share space with nature e.g for habitats

Question 19

Example case of human intervention destroying biodiversity

Answer 19

Laurence et al (2011)

Fragmentation by road networks affecting tree mortality (decline in resilience) which then of course has compounding effects to ecosystem, which will effect the economy too.

Question 20

Note: restoration is more costly than conservation. What is this known as?

And example of not being able to restore at all?

Answer 20

Hysteresis: when ecosystems can be brought back to a state but at a cost.

Rainforests that become savannah cannot be brought back.

Question 21

Natural capital approach steps (3)

Answer 21

1. Valuing natural capital types. (Non-renewable v renewable, or different characteristics require different analysis e.g fragmentation)
2. Incorporate into decision making (assess environmental impacts in decisions)
3. Decide upon trade-off between balancing growth and preservation of natural capital (restoration costs>conserving costs, so be careful, some may not even be able to be restored e.g Savannah rainforests)