Transcript Slide 1
ECONOMIC ASPECTS ON THE CONSERVATION OF BIOLOGICAL DIVERSITY
Göran Bostedt Dept. Of Forest Economics SLU
A comparison between conservation of biodiversity and climate change
• UN Conference on Environment and Development (UNCED) in 1992, the so called Earth Summit, produced two binding conventions: – United Nations Framework Convention on Climate Change, the so called climate convention.
– UN Convention on Biological Diversity, the so called biodiversity convention.
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The story of two conventions...
• The climate convention: on the big stage in research and politics.
– Led to the so called Kyoto protocol in 1997, that emissions of greenhouse gases should be reduced – Summit in Copenhagen 2009 aiming to find a successor to the Kyoto protocol failed.
– UN’s climate panel, IPCC, aims to give scientific support to the political negotiations.
• Biodiversitety convention: the small stage – Led to the Cartagena protocol in 2003, which among other things aims at protecting biodiversity against modern biotechnology.
– Led 2005 to the way as the IPCC .
Millennium Ecosystem Assessment, an attempt at giving support to political negotiations, in a similar
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The story of two conventions...
• The conservation of biological diversity is seen as extremely important in the scientific community.
– “ The central environmental challenge of our time is embodied in the staggering losses, both recent and projected of biological diversity at all levels, from the smallest organisms to charismatic large animals and towering trees.
” Levin (1999): Fragile Dominion: Complexity and the Commons
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The story of two conventions...
• The view that conservation of biodiversity is a central challenge is not shared by policy makers and the general public.
• Why the difference?
• Why has the climate change issue received the political attention that conservation of biodiversity is lacking?
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The story of two conventions...
• Two aspects can help to explain the difference: • The link from human activities to environmental changes.
• The link from environmental changes to human welfare.
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Climate change
• Link from human activities to environmental changes: • Emissions of greenhouse gases cause increasing atmospheric concentration of these gases – this is uncontroversial.
• Increasing concentration of greehouse gases leads to climate change - in principle uncontroversial, but the question is how fast.
• Link from environmental changes to human welfare: • List is long: Sea level changes • Increased storm intensity • Chnages in rainfall, with drought in some places
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Biodiversity
• Link from human activities to environmental changes: • Clear and perceivable evidence – more on this later.
• Link from environmental changes to human welfare: • Less obvious, so far – how are we affected when a species we never heard about goes extinct in the Amazon due to deforestation?
They're running out of rhinos - what do I care?
Let's hear it for the dolphin - let's hear it for the trees Ain't running out of nothing in my deep freeze It's casual entertaining - we aim to please At my parties (Dire Straits)
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Milllenium Ecosystem Assessment 2005
• Ecosystems and biodiversity are essential for human welfare.
• Ecosystem services is the central organising principle.
• Contains a comprehensive account of the status and trends when it comes to biodiversity, in particular when it comes to habitat changes.
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Factors behind the loss of biodiversity
• • • • •
H
abitat destruction
I
nvasive species
P
ollution (including Climate Change)
P
opulation
O
verharvesting
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Human activities and loss of biodiversity
• How can we claim to have a ”biodiversity crisis” when we today know about more species than ever before in the history of mankind?
• To calculate extinction rates: • Species-area curves: n = c * A z where n is the number of species and A is the area of a certain region. The rate of change when A is reduced is then z.
• The value of the parameter z has been estimated for areas like islands. • If z = 0,25 the rate of change in n is 25 times higher than the rate of change in A.
• If we know the rate of change in A – e.g. the deforestation rate in the Amazon, we can say something about the rate of loss in biodiversity.
• Large uncertainties in this method.
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Loss of biodiversity and human welfare
• In the Millennium Ecosystem Assessment this link is largely missing.
• An inconvenient truth: • Rich countries have relatively low biodiversity (Europe, Japan, USA).
• Poor tropical countries have high biodiversity (Afrika, Asia, Latin Amerika).
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Plants in some countries
• Developing countries • Brasil •Malaysia •Costa Rica • OECD-countries • USA • Japan • UK Vascular plants Land area (km 2 ) 56,215 15,500 12,119 8,456,510 328,550 50,660 19,473 5,565 1,623 9,158,960 374,744 241,590
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Loss of biodiversity and human welfare
• Direct benefits: • Consumptive benefits: Harvest for food, fibres, medicin, etc.
• Non-comsumptive benefits: Animal watching, ecoturism • Indirect benefits: • Ecosystem services: Nutrient circulation, purification of water, climate stabilisation • Non-use benefits: • Existence benefits
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Biodiversity and economics – issues for the economist
• What are the consquences of biodiversity loss and what are the consequences of conservation? (costs and benefits) • Which policy measures can be taken and which ones should be taken? (management and policy) • Tools of the economist: •Cost-efficiency analysis •Cost-benefit analysis •Analys of incentives and institutions
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What is biodiversity? -Species diversity -Genetic diversity -Eco system diversity
Noahs ark- problem – Maximizing genetic diversity (Weitzman, 1998) The problem:
max
V
i n
1
c a i
V = Net benefit D(a) = Diversity of the set a of conserved species
ci = Cost of conserving species i
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How do we measure D(a), the diversity of the set of conserved species?
• The easiest way is just the number of conserved species – species richness.
• Species richness is probably the most common measure of biological diversity.
• Ecologists are quick to point out that there are more important aspects than species richness.
• Why care about species richness?
• Species richness is connected to productivity, measured as biomass/area.
• Species richness is important for bioprospecting and gives greater resilience.
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Beyond species richness – taking uniqueness into account * Genetisk diversitetsmått kan baseras på evolutionära träd
• One can argue that species without close relatives should be prioritized: uniqueness is valuable Figur 6.3 Släktträd för hominoider (från Weitzman, 1992)
Diversitetsmått baserat på evolutionärt träd Art Antal noder
noder noder i
Människa Chimpans Gorilla Orangutang Gibbon Siamang Summa 4 4 3 2 2 2 17 17/4 = 4,25 17/4 = 4,25 17/3 = 5,67 17/2 = 8,5 17/2 = 8,5 17/2 = 8,5 39,67 Sveriges lantbruksuniversitet
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distance, for instance in DNA
measure on cranes (from Weitzman, 1993): *Applying Weitzman’s
Pairwise distances A-B: 3 A-C: 1 A-D: 4 B-C: 4 B-D: 4 C-D: 5 Nearest neighbour A-B + C + D = 8 A-B + D + C = 8 A-C + B + D = 8 A-C + D + B = 8 A-D + C + B = 8 A-D + B + C = 8 B-C + A + D = 9 B-C + D + A = 9 B-D + C + A = 9 B-D + A + C = 8 C-D + A + B = 9 C-D + B + A = 10 * The diversity of the set {A, B, C, D} = 10 Sveriges lantbruksuniversitet
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The crane family
Species Black crowned crane Grey crowned crane Demoiselle crane Blue crane Wattled crane Siberian crane Sandhill crane Saurs crane Brolga crane White-naped crane Eurasian crane Hooded crane Whooping crane Black-necked crane Japanese crane
Applying Weitzman’s measure on cranes (from Weitzman, 1993):
Latin name Geographical area Probability of extinction
Balearica pavonina
Central Africa 0,19
Balearica regulorum
Souteast Africa 0,06
Anthropoides virgo
Central Asia Anthropoides paradisea Southern Africa Bugeranus carunculatus Southeast Africa
Grus leucogeranus Grus canadensis
Asia North America 0,02 0,1 0,23 0,35 0,01
Grus antigone Grus rubicunda Grus vipio Grus grus Grus monachus Grus americana Grus nigricollis Grus japonesis
Southeast Asia Australia East Asia Europe, Asia East Asia North America Himalaya East Asia 0,05 0,04 0,21 0,02 0,17 0,35 0,16 0,29
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* Bevarandediagnostik för tranfamiljen : Species Probability of Extinction in 50 years Marginal diversity Black crowned Crane (Africa) Grey crowned Crane (Africa) Demoiselle crane (Asia) Blue crane (Africa) Wattled crane (Africa) Siberian crane (Asia) Sandhill crane (North America) Saurus crane (Asia) Brolga crane (Australia) White-naped Crane (Asia) Eurasian crane (Eurasia) Hooded crane (Asia) Whopping crane (North America) Black-necked Crane (Asia) Red-crowned Crane (Asia) Sum 0.19 0.06 0.02 0.10 0.23 0.35 0.01 0.05 0.04 0.21 0.02 0.17 0.35 0.16 0.29 8.7 14.1 7.0 4.8 7.8 10.3 11.1 4.7 6.5 9.2 1.3 1.4 4.5 5.8 2.9 100 Elasticity of diversity (% increase in diversity from 1% decrease in probability of extinction) 11.3 5.8 0.9 3.3 12.3 24.6 0.8 1.6 1.8 13.1 0.2 1.6 10.7 6.3 5.7 Sveriges lantbruksuniversitet 100
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Compare the Sandhill crane and the Whopping crane (both North American species). Although the marginal diversity of the Sandhill crane is larger, a dollar is better placed on the Whopping crane since it is more endangered.
The Siberian crane has very high elasticity of diversity, and therefore very high conservation potential. Combines uniqueness with high probability of extinction.
Note that the above table gives no information about the marginal cost of decreasing the extinction probability – a necessary piece of information to complete an economic analysis.
Today, instead of making a systematic trade-off between uniqueness and extinction risk, we simply wait until a species is on the brink of extinction and then decide to save it, almost regardless of the cost.
It makes sense to look hard at indicators such as expected diversity gain per conservation dollar.
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Conserving species for genetic prospecting *A commong argument is that biodiversity is important as a source for future medical drugs – genetic prospecting.
*In USA almost 25% of all prescribed medicin contain active ingredienses from plants.
*As a source of clues in agricultural and medical research and certain other areas natural organisms are very hard to replace. In this sense there is simply no substitute for biodiversity as a wholes. *However, the decision is usually marginal – should a marginal hectare of rain forest be cut down or conserved for genetic prospecting? In such a situation it is not the huge value of all biodiversity in the tropics that counts, but the benefits and cost for genetic propecting
on the margin
.
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*The expected value of preserving a marginal hectare for genetic prospecting depends on: 1) The expected value of the medical drug 2) The probability that the source of the drug is in that marginal hectare. Even if 1) is high the probability in 2) is very low unless the number if alternative hectares of rain forest are low. A variant of the ”water-diamond paradox”. Conclusion: This type of argument doesn’t hold up, other benefits are more important on the margin, like the benefits of ecosystem services and existence values. Sveriges lantbruksuniversitet
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Ecosystem services
• In the Millennium Ecosystem Assessment ecosystem services are devided into four different categories: supporting, regulating, cultural och providing.
•
Supporting
(understödjande): ecosystem functions that serve as a kind of base and are essential for other functions. Can be nutrient and water circulation.
•
Regulating
purification.
(reglerande): more specific functions, e.g. pollination, air and water •
Cultural
values. (kulturtjänster): all use for emotional wellbeing, e.g. estetic and recreational •
Providing
(tillgodoseende): the most obvious ecosystem services, like food and raw materials, which become goods.
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A framework for valuing ecosystem services
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Three challenges in valuing ecosystem services
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Challenge 1
• To understand the ecological system and how it contributes to goods and services that benefits humans.
• To understand how changes in the ecosystem leads to changes in the production of these goods and services.
• The ”ecological production function”.
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Challenge 2
• To understand the value of the goods and services that the ecosystem produces.
• To understand the distributional effects – who gets the ecosystem services?
• The ”value of ecosystem services”.
• Some have market prices, but many have not.
• Today few non-market priced ecosystem services have been valued.
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Challenge 3
• An integrated analysis – to combine ecology (and other natural sciences) with economics and other social sciences) in an integrated analysis.
• To convert this analysis to policy recommendations.
• Much of this research remains to be done.
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Conservation strategies
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Conservation strategies
• Assume we have decided on a goal and we have an operational definition of this goal.
• How can we: • Maximize the goal fulfillment given limited resources (cost-efficiency analysis.
• Reach a socially efficient outcome (CBA).
• Conservation strategies can imply: • Land-use changes • Control of invasive speciesKontroll av invasiva arter • Harvest policies • Emission control
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Cost-efficient conservation strategies
• Is focused on habitat conservation through the creation of reservations/protected areas.
• More known as:
THE RESERVE SITE SELECTION PROBLEM (RSSP) Sveriges lantbruksuniversitet
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*RSSP is based on the idea that the only way to conserve biodiversity is to establish protected areas. *The baseline assumption is that today’s reserve system is inoptimally chosen. Historically researvations have often been established because: The opportunity cost was low since the land had few competing uses. This can explain why many protected areas have been established in the mountain region, while a relatively small share of the nature in southern Sweden has been protected. Similar trends can be found in other countries. Estetic reasons may have been important. A certain nature area may have been protected because of a majestic waterfall or some strangely shaped rocks were there. This type of nature conservation can be motivated on recreational grounds. Other reasons. The recreational needs of citizens in large cities can motivate the establishment of protected areas near such cities. Chance can also play a role, like if areas have been donated to the state.
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Land area of Sweden divided in ownership categories and geographical areas, share in reservations (% res), according to the Swedish National Forest Inventory
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Guiding principles behind a reserve network
Complementarity
. With limited resources to establish new reservations they should be chosen to complement already existing ones. Reservations in mountain regions can be complemented with reservations in the forest land, reservations in the northern part of a country can be complemented with reservations in the southern part, etc. Together the reservations can encompass most nature types in a country.
Flexibility
. Often several sites can fulfill the same biodiversity goals. One should therefore not be locked at certain areas in say, the mountain region, if there are substitute sites that give the same protection of biodiversity.
Irreplaceability
are chosen.
.
Certain areas may be irreplaceable in a reserve network, for instance in the sense that certain threatened species only exist in a certain area. For these areas no substitutes exist and complete coverage of all threatened species cannot be achieved (in the sense that they are represented in the reserve network) cannot be reached unless they
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*The problem – called the
Maximum Coverage Problem (MCP)
: Find a set of reserves that ”covers” as many species as possible in as small an area as possible (MCP1).
Maximize the number of ”covered” species within a given budget, where different areas have specific cost associated with setting them aside (MCP2).
*Information requirements: -MCP1: A geographical species data base.
-MCP2: As in MCP 1 + a geographical land value data base.
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Example of a geographical species data base. Species 1 Species 2 Area 1 Area 2 : : Area
m
1 0 : : 0 0 1 : : 0 ………. ………. ………. Species
n
1 1 : : 1
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* One way to find the optimal solution is through integer programming using branch-and-bound algoritmer computer intensive method if the number of species and/or areas is large. *A number of heuristic ( approximative) algorithms exist, which can find a nearly optimal solution. The Greedy Algorithm: First choose the area with the most species, then the area with the most species that didn’t exist in the first area, and so on. The Rarity Algorithm: Weigth each species by 1
N j
, then choose the area with the largest sum of “species weights”. Remove the “covered” species from the process and redo the iteration.
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Simple example: choose 2 out of 4 areas as reserves
A och B är hotspots.
According to the Greedy Algorithm we should choose either A or B, then either C or D But the obvious optimal choice is C and D.
Illustrates the importance of complementarity.
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* the Oregon study – some results: -Optimal solution: 90% of the species could be covered with 5 areas out of 441, i.e. 1,1% of the area of Oregon. All the species could be covered with 23 areas out of 441, 5,2% of the area of Oregon. The Greedy Algorithm was nearly optimal when only a few areas could be selected, so that not all species could be covered. • The Rarity Algorithm was nearly optimal when it came to covering all species (24 areas rather than the optimal 23 was needed).
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450 430 410 390 370 350 330 310 290 270 250 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Girighetsalgoritmen Ovanlighetsalgoritmen Optimal lösning - heltalsprogrammering
Antal områden i reservatsnätverket
Species accumulation curves
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The Rarity Algorithm gives high weight to unusual species.
There is not only one but 144(!) optimal solutions.
How come? Several areas are perfect substitutes to each other.
But 19 of the 23 areas appear in all the 144 solutions and are thus irreplaceable in a reserve network.
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Irreplaceability values for Oregon reserves.
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*If costs are included the problem changes (MCP2):
Max
.
y i
(1)
i x j
y i j
B I
(2) (3)
y i
= species i I = tot. number of species
x j
= area j J = tot. number of areas
N c j i
J
= areas where species i exist, subset of J = cost for conserving area j B = budget restriction
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*Example - County USA study (Ando et al., 1998, Science) *Based on occurrence data on the 911 species That are listed under the Endangered Species Act. *USA has 2851 counties. Land value = value of agricultural land. *Assumption: Species are evenly distributed within a county. It is therefore Enough to conserve arbitrarily large area in every chosen county. The size of this area does not influence the choice of counties. *Results: The cost of conserving 50% of the threatened species is only 7,5% of the cost of conserving all of them. Reason: To conserve all threatened species some counties with extremely high land values, like San Fransisco county must be included.
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Concluding thoughts
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Conservation and economics
Economic research has much to contribute with when it comes to making rational decisions in conservation issues, for instance through cost-efficiency analyses and CBA.
Conservation biology – an established research field.
In a similar way one could talk about
Conservation economics
as a research field.
There are many challenges:
To measure the value of ecosystem services To measure existence values To integrate realistic ecological models with economics Spatial issues (migration, reserve site selection, etc.)
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Conservation and economics (continued)
More challenges:
Irreversibilities (extinction etc.) Incorporate climate change Technological development
This requires cooperation between economists and ecologists!
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