Planetary boundaries(Human impacts on the environment) Flashcards
what are the 9 processes that regulate the stability of the land, atmosphere, and sea
Atmospheric aerosols
Biodiversity integrity
Fresh water use
climate change
ozone depletion
Biogeochemical flows( nitrate and phosphate)
Novel Entities(inorganic pollution boundary)
Land- System Change
Ocean Acidification
what is the aim of the planetary boundary concept
to define environmental limits within which humanity can safely operate
causes of the climate change boundary
increase in greenhouse gas levels, particularly carbon dioxide levels
what does an increase in carbon dioxide levels cause
Global warming
2 activities that lead to an increase in greenhouse gas levels
deforestation
burning of fossil fuels
what is the boundary for climate change
atmospheric concentrations of carbon dioxide should not exceed 300ppm
what are the consequences if the climate change boundary is exceeded
*could lead to thermal expansion and melting of ice caps which raise the sea level, leading to flooding of low-lying lands, habitat destruction, and reduction in biodiversity.
- Increased temperature affects wind
patterns, ocean currents, and rainfall.
These affect the survival of plants and
animal species in certain areas.
measures to prevent us from exceeding the climate change boundary
- Reduce/stop burning fossil
fuels - Reduce deforestation
- Alternative fuel sources
including biofuels
Biofuels
Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil.
Boundary for biodiversity
Maintain 90% of biodiversity
causes of biodiversity loss
- Habitat destruction
e.g. tundra, coral
reefs, tropical rain
forests, marine - Hunting
consequences of loss in biodiversity
Reduction in species number/ extinction, as the species, cannot evolve quickly enough to adapt to the environmental changes caused by humans
4 ways to protect species
- Monitor biodiversity
- Species conservation via
gene banks e.g. seed banks,
sperm banks - Prohibit international trade in endangered species and their products
- Fishing quotas
*increase public awareness
what is the land use change boundary
maintain 75% of the planet’s original forests
the problem with land use change
- Land use change
(including
deforestation) for
food and biofuel
production, urban
development,
livestock farming,
consequences of exceeding the land use change boundary
- The production of biofuel crops and
crops grown for export means that
not enough food may be produced for
local use. - Reduction in biodiversity
how to live within the land use change boundary (remedial measures)
- Farming should be
concentrated in the most
productive areas only. - Reduce meat consumption.
causes of the biogeochemical flow boundary(nitrate and phosphate boundary)
- Use of fertilizers
containing nitrates
and phosphates. - Agricultural nitrogen fixing
- combustion of fossil fuels and biomass
what is the boundary for biogeochemical flow
Worldwide use per year of about
11 teragrams (Tg) of phosphate and 62 Tg of
nitrate
consequences of exceeding the biogeochemical flow boundary
Eutrophication from nitrate and
phosphate run-off into bodies of
water
remedial measures for the biogeochemical boundary
Reduce the use of fertilizers
the ozone boundary
Less than 5% below pre-industrial level of about 290 Dobson Units
causes of the ozone boundary
CFC use in aerosols,
refrigerator coolants
etc
consequences of exceeding the ozone boundary
- Ozone layer destruction
- Increase in UV light increasing DNA
mutations, skin cancers, and cataracts
remedial measures to solve the problem with the ozone boundary
CFCs were banned and the
the ozone layer is re-building.
ocean acidification boundary
When the oceans become acidified
enough that the minerals that sea creatures
need to make shells begin to dissolve
causes of the ocean acidification boundary
- Burning fossil fuels
and increased carbon
dioxide levels. - Carbon dioxide
dissolves in seawater
and forms H2CO3
which releases H+ ions
/ lowers pH/ increases
acidity
consequences of exceeding the ocean acidification boundary
- Low pH causes calcium carbonate to
leach out of corals, the shells of
mollusks and the exoskeletons of
Arthropods. Even if the organisms
survive this, they become softer and
more vulnerable to predators. - Could reduce biodiversity
remedial measures to deal with problems of ocean acidification problem
Reduce carbon dioxide
levels by reducing fossil fuel
combustion and
deforestation.
the freshwater boundary
We can use up to 4000km2 of freshwater per year
causes of the freshwater boundary
- Increased water use in
Agriculture (irrigation)
and industry. - Climate change
- Pollution of water
- Change in land use
e.g. draining wetlands,
deforestation
consequences of exceeding the freshwater boundary
Reduction in freshwater available
remedial measures to deal with the problem of the freshwater boundary
- Stop irrigating non-food
crops e.g. biofuels - Reclaim waste water for
irrigation/industry - Use desalinated water
the aerosol boundary
unknown
causes of the aerosol boundary
The atmosphere
contains minute
particles such as ash
and soot from burning
and coal power
stations, dust from
quarrying.
consequences of using too much aerosol
- Increase in respiratory problems and
lung cancers. Estimated to cause
800,000 premature deaths per year - It can build up on leaves and reduce
photosynthesis
remedial measures to deal with the problem of the aerosol boundary
we are unable to determine safe limits currently(unknown)
causes of the inorganic pollution boundary (novel entities)
- synthetic organic
pollutants e.g. DDT,
PCBs - radioactive materials
- micro-plastics e.g.
plastic beads in
cosmetics
consequences of exceeding the novel entities’ boundary
Bioaccumulation in food chains and webs
remedial measures taken to deal with the problem of the novel entities’ boundary
- Some novel entities are
already controlled e.g. the
use of DDT is banned. - But of the estimated 100
000 manufactured
chemicals and other
entities, few have been
properly assessed.
endangered species
a species whose number and genetic diversity have been reduced to the extent that their long term survival is in doubt
planetary boundaries
limits between which global systems must operate to prevent abrupt and irreversible environmental change.
