Prospects for BiodiversityProspects for Biodiversity

Author: Martin JenkinsAuthor: Martin Jenkins

Summary: Chase MahoneySummary: Chase MahoneyCritique: Asa AngelesCritique: Asa Angeles

IntroductionIntroduction

9,000,000,000 people9,000,000,000 people Imagine their impact.Imagine their impact. ““What will be the state of the world’s What will be the state of the world’s

biodiversity in 2050?”biodiversity in 2050?” Prospects for BiodiversityProspects for Biodiversity offers an answer offers an answer

to this question.to this question.

OverviewOverview

Assumptions for extrapolationAssumptions for extrapolation Human influences and their impactsHuman influences and their impacts

– Terrestrial EcosystemsTerrestrial Ecosystems– Aquatic EcosystemsAquatic Ecosystems

Do these impacts matter?Do these impacts matter?

Assumptions for ExtrapolationAssumptions for Extrapolation

United Nations global population estimationUnited Nations global population estimation– 9 Billion (2050)9 Billion (2050)– 6-7 Billion (2003)6-7 Billion (2003)

The human race will conduct its affairs in much the The human race will conduct its affairs in much the same manner as today.same manner as today.

Intergovernmental Panel on Climate Change Intergovernmental Panel on Climate Change ScenariosScenarios– 11ooC to 2C to 2ooC increase in average surface temperature.C increase in average surface temperature.

– 100 to 200 ppm increase in CO100 to 200 ppm increase in CO22 concentration. concentration.

Major Human Influences onMajor Human Influences onLandLand

Habitat conversionHabitat conversion– Clearing land for farmingClearing land for farming

IntensificationIntensification At least 120 ha by 2030 At least 120 ha by 2030 By 2050 much moreBy 2050 much more South America and sub-Sahara AfricaSouth America and sub-Sahara Africa

– Most biologically diverse regions in the world.Most biologically diverse regions in the world.– Disproportionate loss in biodiversityDisproportionate loss in biodiversity

Major Human Influences onMajor Human Influences onLandLand

Habitat conversionHabitat conversion– Clearing land for farmingClearing land for farming

Dense tropical forest -> Fragmented/DegradedDense tropical forest -> Fragmented/Degraded Resemble temperate forests of North AmericaResemble temperate forests of North America 350 species of avifauna (3.5%) will become extinct.350 species of avifauna (3.5%) will become extinct. Surviving species live in heavily protected managed Surviving species live in heavily protected managed

areas.areas.

Major Human Influences onMajor Human Influences onAquatic EcosystemsAquatic Ecosystems

Habitat ConversionHabitat Conversion– Destruction by siltationDestruction by siltation

Land runoffLand runoff Coastal developmentCoastal development

– PollutionPollution

– Large-scale HydroengineeringLarge-scale Hydroengineering

Major Human Influences onMajor Human Influences onAquatic EcosystemsAquatic Ecosystems

Habitat ConversionHabitat Conversion– Fresh water biodiversity Fresh water biodiversity

has suffered the has suffered the heaviest losses over the heaviest losses over the last 30 years.last 30 years.

– These losses are These losses are expected to continueexpected to continue

– Coral Reef destructionCoral Reef destruction

Major Human Influences onMajor Human Influences onAquatic EcosystemsAquatic Ecosystems

Exploitation of wild resourcesExploitation of wild resources– Direct exploitation through fishingDirect exploitation through fishing

Current rates lead to extinctionCurrent rates lead to extinction Large species and top marine predators scarce or Large species and top marine predators scarce or

extinct.extinct.

Does it Matter?Does it Matter?

Ecologists and Conservationists struggle to Ecologists and Conservationists struggle to demonstrate benefits of diverse intact demonstrate benefits of diverse intact systems.systems.

Diverse species-rich systemsDiverse species-rich systems

Intensively managed systems of nonnative Intensively managed systems of nonnative species (farms)species (farms)

Does it Matter?Does it Matter?

Benefits are marginal and localBenefits are marginal and local– Few cases have shown benefits of natural Few cases have shown benefits of natural

systemssystems

Forest destructionForest destruction– Infertile unusable land has obvious impacts on Infertile unusable land has obvious impacts on

human existence.human existence.– Replacement shows no negative impacts.Replacement shows no negative impacts.

Does it Matter?Does it Matter?

Experts agree most large terrestrial species Experts agree most large terrestrial species are extinct as result of human influence.are extinct as result of human influence.– 40,000 to 50,000 years40,000 to 50,000 years– Systems we consider natural aren’t so.Systems we consider natural aren’t so.– Don’t show catastrophic consequences.Don’t show catastrophic consequences.

Does it Matter?Does it Matter?

Real life exampleReal life example– 38 species of avifauna existed in New Zealand.38 species of avifauna existed in New Zealand.– 9 exist today 9 exist today

Most of which are endangeredMost of which are endangered

– Huge loss of biodiversityHuge loss of biodiversity No signs of suffering from a crisis.No signs of suffering from a crisis.

– On what grounds can we base our belief that On what grounds can we base our belief that similar losses will result in crisis in other areas.similar losses will result in crisis in other areas.

Does it Matter?Does it Matter?

Still may Still may notnot abuse the biosphere abuse the biosphere indefinitely.indefinitely.– Unforeseen threshold Unforeseen threshold – Catastrophic consequencesCatastrophic consequences

More likely cause of catastrophic More likely cause of catastrophic consequences will be abrupt climate shifts.consequences will be abrupt climate shifts.– May begin with manipulation and abuse of the May begin with manipulation and abuse of the

biosphere.biosphere.

ConclusionConclusion

Jenkins scenario assumptionsJenkins scenario assumptions– ClimateClimate– PopulationPopulation– Similar method of conductSimilar method of conduct

Human actions have direct influences on Human actions have direct influences on surrounding ecosystems.surrounding ecosystems.

Losses in biodiversity do not have immediate Losses in biodiversity do not have immediate negative impacts on human existence.negative impacts on human existence.– Still be aware our impact may eventually trigger other Still be aware our impact may eventually trigger other

catastrophic events.catastrophic events.

Prospects for BiodiversityProspects for Biodiversity

By Martin JenkinsBy Martin Jenkins

Summary: Chase MahoneySummary: Chase MahoneyCritique: Asa S. AngelesCritique: Asa S. Angeles

Critique OutlineCritique Outline

Positive CritiquePositive Critique– CitationsCitations– Good PointsGood Points

Constructive CriticismConstructive Criticism QuestionsQuestions

Positive CritiquePositive Critique

EvidenceEvidence– 24 citations, including links to web sources24 citations, including links to web sources

Year of Publication of Citing Articles

0

1

2

3

4

5

6

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

Living Planet IndexLiving Planet Index

282 species 195 species 217 species

Other Good Aspects of the Other Good Aspects of the ArticleArticle

Honest tone; mostly not over-dramatizedHonest tone; mostly not over-dramatized– Says estimating extinction rates is difficultSays estimating extinction rates is difficult– Admits that scientists struggle to show human Admits that scientists struggle to show human

benefits from “intact” wild systemsbenefits from “intact” wild systems– New Zealand went from 38 to 9 species of birds New Zealand went from 38 to 9 species of birds

in a few centuries, but does not sufferin a few centuries, but does not suffer The future will probably be this wayThe future will probably be this way

Constructive CriticismConstructive Criticism

Minor: Of the 24 citations, 7 are Minor: Of the 24 citations, 7 are ScienceScience articles articles How much does it matter?How much does it matter?

– Says “natural” systems that really aren’t natural still Says “natural” systems that really aren’t natural still function (recall New Zealand)function (recall New Zealand)

– But somewhat dramatizes at the end: “…some threshold But somewhat dramatizes at the end: “…some threshold may be crossed, with unforeseeable but probably may be crossed, with unforeseeable but probably catastrophic consequences for humans.”catastrophic consequences for humans.”

– Then he immediately takes back this claim: “It seems Then he immediately takes back this claim: “It seems more likely that these consequences would be brought more likely that these consequences would be brought about by other factors.”about by other factors.”

– So…How much does it matter?!So…How much does it matter?!

Questions?Questions?