PLANETARY BOUNDARIES
1. Ocean acidification
o Ongoing decrease in the pH
(increased acidity) of oceans
o Absorption of excess CO2 from the
atmosphere
o Carbon sink problems
o Human triggers: CO2 emissions
o Impaired calcification: produce and
deposit calcium carbonate (shells,
skeletons, exoskeletons)
o #SavetheCorals
➢ Rainforests of the sea
➢ Coastal protection – storm
surges and high waves
➢ A keystone species
o
Human Triggers:
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2. Ozone depletion
o Depletion of the stratospheric
ozone layer
o Ozone: higher concentration of
ozone (O3) molecules
o Decreased capability to absorb (esp.
B&C)
➢ UV-A: longest wavelength
but least energetic (deeper
skin and eye penetration)
➢ UV-B: medium wavelength
but more energetic than
UV-A (sunburn, aging,
cancer)
➢ UV-C: shortest wavelength
but most energetic (DNA
damage)
Human triggers:
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Chlorofluorocarbons (CFCs)
- Refrigeration and air conditioning,
aerosol propellants (deodorants,
hairsprays, and insect repellants)
Halons
- Fire suppression systems
Carbon Tetrachloride
- Solvent and a cleaning agent
3. Biogeochemical Flows
o Interference in Nitrogen and
Phosphorous cycles
➢ How it moves around the
earth systems in various
forms
Eutrophication – Nitrogen and
Phosphorous bombing of aquatic
ecosystems
➢ Initial attraction: Nutrientrich
➢ Overwhelming input: Algal
bloom
▪ Overpopulation
➢ Negative consequences:
▪ Oxygen depletion
▪ Dead zones – low
oxygen areas
(hypoxic)
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Agricultural runoff
- Substances OTW bodies of water
❖ Fertilizer – P&N-based
❖ Animal manure – P&N rich
Human sewage and wastewater
- Improperly treated and managed
4. Chemical Pollution
o Proliferation of chemicals (millions):
atom-made substances (S,L,Q)
➢ Natural – Ethanol, ascorbic
acid, essential oils, etc.
➢ Synthetic – Polyethylene,
fertilizers, antibiotics, etc.
o Air, water, and land contamination:
Improper handling, storage,
disposal
➢ Heavy metals –
construction, electronics,
manufacturing (mercury,
cadmium, arsenic, and
chromium).
➢ Radioisotopes – medicine,
research, testing (Iodine131, Carbon-14, Uranium235)
o Persistent Organic Pollutants &
Plastics
➢ POPs: chemical byproducts
(Chem production: dioxins
& furans)
➢ Plastics: lightweight,
durable, and malleable
objects made from polymer
o
➢ Both: Persistent, BA and
BM, globe-trotters
Bioaccumulation and
Biomagnification
➢ BA: chemical build-up
➢ BM: chemical multiplication
Human Triggers:
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Agriculture
Pharmaceuticals
Food and beverage
Construction
Electronics
5. Freshwater use
o Excessive and unsustainable use of
freshwater (3.5%)
o Unsustainable using something as if
it’s limitless.
o Land Subsidence
➢ Gradual sinking or settling
of the Earth’s surface.
o Water scarcity
o Ecosystem and economic disruption
o Social and political conflict
7. Biodiversity loss
o Deforestation
o Urban development
o Agriculture
o Mining
o Poaching and wildlife trafficking
SO WHAT:
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8. Atmospheric Aerosol Loading
o Concentration in the atmosphere
o Aerosol: solid/liquid particles
suspended in the air (natural &
anthropogenic)
SO WHAT
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Human Triggers:
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Agriculture – irrigation
Fashion/textile – washing, dyeing, and
finishing.
Energy – cooling
6. Land-system change
o Ongoing and widespread land
conversion
o Land degradation – soil erosion,
desertification, fragmentation
o Habitat destruction and biodiversity
loss
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Agriculture – crops and livestock
farming
Infrastructure Development – roads,
highways, airports, and dams
Mining
Air quality degradation
Reduced visibility
Climate change
✓ Cooling: Aerosol scattering
- Sulfate Aerosols
✓ Warming: Aerosol Absorption
- Black Carbon
Human Triggers:
✓ Fossil fuel combustion
✓ Biomass burning
✓ Industrial processes
THE ANTHROPOCENE
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Human Triggers:
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Goodbye keystone species: main
character in an ecosystem.
✓ Ecosystem engineers – habitat
and landscaper
✓ Predators
✓ Pollinators – matchmakers
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Anthro (man) + cene (new)
Unofficial geologic epoch (official:
Holocene)
o Period in Earth’s history
o Geologic and environmental
conditions
➢ Rock layers and fossils
Human-dominated epoch
✓ Population
✓ Activities
✓ Impacts
Ongoing debates
-
Have humans truly left a mark on
earth?
When did it begin?
Who is/are actually driving global
changes with global impacts?
WHY MAKING IT OFFICIAL IS A BIG DEAL
1. Human accountability
- Not everything is natural
2. Scientific framework
- Human impacts are real and valid
3. Environmental governance
- basis for policy and regulation.