Global change The Future LECTURE 3

Projected changes in drivers

1. Population growth

2. Changes in geography of the population

3. Grwoth in the glocal economy

1. Population growth

• 10 billion people

• Even if fertilitiy fell sharply→ still would be 9 mmillion

2. Chnaging geography of population

• Urbanisation→ 70% in 2050

  • Increased efficeciency of resource use

• Disproportionate growth projections in Africa

  • likely to double 2010-2060

note: growth is varied

3. Growth in the economy

• projected at 130% growth porjection

• per capita GDP will outstrip population growth

→ Can change relative decoupling to absolute decoupling

Relative decoupling

• resources use/ $ is declining

Absolute decoupling

• resource use/$ is declining faster than the global encomy is growing!

Projected changes in threat

1. Habitat conversion

2. Over harvesting

3. Climate change

4. Invasive species

5. pH of ocean

6. Pollution in ocean

1. Habitat conversion

• More wealthy people deamnd more food

• especially high footprint products e.g meat and dairy

• Need more cropland than today

• ESPECIALLY→ Sub-saharan Africa→ Dramatic growth but chronically low yields

  • Must use up even more African land→ biodivsery threat a very high

2. Overharvesting

• Trees and fish→ more important than habitat loss

Especially

• megafauna

3. Climate change→ greenhouse gases

• The near-term descion agreements now will determine emissions trajectories

• Business as usual emissions→ causes >4 degree heating by 2100 over preindustrial levels

  IMPACT→ 16% of all species to extinction

  • marine extinctions comparable to end-Permian event by 2300

But even if pledges were met

→ still eliminate 7 to 8% of species

Need more stringent measures!

4. Invasice species

Likely to rise:

• Increase in global shipping→ 1200% by 2050

5. pH of oceans

• fall by -.3pH unites by 2100

• more acidic than they were past 40My

6. Pollution in the ocean

• Eutrophication

• accumulation of plastic debris

• bioaccumulation os persistant organochlorines in the tissues of apex predators

  • like the killer whales

Cumulative effects of projected threats!

1. Extinction rates→ increase by x5

2. CO2 and temperature increase and habitat conversion» last deglaciation

3. Several regional scale state-shifts

   • irreversible transitions from one state to another

   • AND

   • They can interact→ making glocal-scale state shift plausible!

Reasons for thinking these effects could be solved!

1. Trends in the level of conservation responses

2. Conservation improves habitas and populations

3. Conservation is tackling the drivers underlying core threats

4. Public levels of concern are growing

5. Many of the changes being made can also positively impact other issues

1. Trends in the level of conservation responses

• conervation seems to have accelerated

• Now targets to protect at least 30% of terrestrial, freshwater, coastal and marine areas in PAs and OECMs

Although:

• These must really be effective in helping meet rising human deamnd for food, fibre and energy!

2. Conservation improves habitats and populations

Conservation seems to be improving habitats and populations

AND slowing down exticntion rates

• e.g 26 highly endangered mammals species→ 7-16 would have gone extinct by now, BUT HAVE NOT!

• Extinction have reduced by a factor of 2.4-4.2

3. Conservation is tackling the drivers underlying core threats

E.g Tackling the need for more cropland by:

• cutting food waste

• shifting towards plant-based diets

• increasng crop yeilds

e.g in AFrica

• 80% yield gap closed

• → halves the area of extra crop land needed

4. Public levels of concern are increasing

• higher than education

5. Many of the changes being made can also positively impact other issues

e.g Tackling food security→ ALSO natural climate solution

• cutting food waste

• increase yields

→ ALSO HELPS

• restore forest on low-yielding grasing lands

• stops further deforestation

→ Adds a 20% reduction in emissions needs to achieve net-zero

Case Study 1: Mauritius→ How it is going

• intensive hands-on managmenet of several critically endangered birds

• promoted more species managment

• Re-introductions into the wild!

Case Study 1: What needs to be done next?

• Extend to overlooked species

• e.g endemic invertebrates and habitats (caves)

Case Sudy 1: Next steps→ Rewilding

Ecological replacement (taxon substritution)

• replacing extinct species witht the next best thing to take up the ecologial niche

E.g example of rewilding

Species that went extinct→ tortoises, needed for

• large seed dispersal

• exerted strong selesction for grazing herbs and grasses

Replacement→ new tortoises

• To Ile aux Aigrettes

Effect:

• seedlings appear right across islet

• not beneath plants any more

• pass through gut→ Increased germination

• promoted palm-rich habitat important for endemic skinks and geckos

Other ways to rewild

Genetic engineering→ e.g dodos

• but many argue these are unhelpful distractions!

Case study 2: Great Whales→ How it is going

1. Norway and Japan still doing it for research

2. Japan banned

3. Jan withdrew from International whaling commission

4. Still whaling!

Case study 2: Positives that may help?

INcrease in whalewatching

• 13M people worldwide paying to see whales

• 2.1B/y to regional economies

• Even in Japan

Case study2: Effect of this?

• Japan whale meat prices→ too high→ uptake is limited

→ Globally no longer a majoe threat

• 5/7 whale species with reliable population estimates now considered to be increasing!

Case Study 2: New threats coming?

1. Noise pollution growing from (although causation is not clear)

   • shipping (which is growing)

   • seimis surveys

   • military sonar

2. Shipping strikes is series

   • Solution?

     • Decrease speeds

     • re-routing shipping lanes

     • training pilots

3. Entanglement in fishing gear abandomned

   • 300K deaths/y

   • solution?

     • The marine lobsters are overfished

     • so if decrease fishing effort

     • would boost profit and help right whale recovery!

4. Climate-linked shifts in prey e.g for North Atlantic right whale

Case study 3: Amazon→ How it is going

1. Hunting is a growing problem

2. Deforestation is accelerating

Case study 3: How to decrease hunting

1. Tried to suggest chicken substriture

   → DID NOT reduce wild meat consumption

2. Give cookery lessons and public commitments to reduce wild meat consumption

   → Did help!

Note: reducing unsustainable hunting may require similary nuance interventions elsewhere

Why was deforestation accelerating

• Bolsonaro regime

Consequences of further deforestation

1. Extinctions accelerate→ 25% of Amazon’s tree species and contiues to 57%

2. Carbon sink lost

3. Moist forest→ savanna

   • deforestation lowers evapotranspirative loss, reducing rainfall, turn further reduces evapotranspitation

   • Rapid switch to savanna-like vegetation

   • Bad for agricultureal areas!

Case study 3: Optimism?

1. Political and economic pressure

2. Proven tools for slowing deforestation

3. Abandoned by farmers→ Restoration

4. Carbon credits

5. Increasing yields

1. Political and economic pressure

• National and international

• return of Lula de Silva

• committed to net-zero deforestation by 2030

2. Proven tools for slowing deforestation

Proved that things can slow deforestation substationally!

• protect areas

• market and regulation driven carrot and stick interventions on private land

→ Deforestation rates have rouhly halved!

3. Abandoned by farmers→ Restoration

• 23% of recently cleared forest has been abandoned

• could support deforestation

• restoriation!

5. Carbon credits

• Glocal carbon prices increased 16-fold

• payments of carbon creits could be a good incsetise to reatin forest cover!

5. Increasing yields

• Cattle stocking is only at about 1/3 carrying capactiy

• raise to 50%→ meets Brazil’s target for agriculture

• At the same time as

• stopping further deforestation

• ALSO: meet Chinease soy demand

Conclusion

• If we continue business-as-usual, a sixth mass extinction will probably be triggered and climatic tipping points breached –

• but the evidence suggests already we have much of the knowledge and the means to avert these outcomes, if we choose