human impact on environment Flashcards
what are planetary boundaries?
a threshold value for a global process that is affected by human activity
what are the 9 planetary boundaries?
climate change
biodiversity
land use
biogeochemical cycles
ozone
ocean acidification
freshwater
aerosol
novel entities
what are the causes of climate change?
burning fossil fuels
deforestation
increase in greenhouse gases
what are the consequences of climate change?
increase global temos
impacts on wind patterns/rainfall
thermal expansion / melting of ice caps
what are the possible remedial measures for climate change?
stop burning fossil fuels
reduce deforestation
alternative fuel sources
what are the causes of loss in biodiversity?
habitat destruction
what are the consequences of loss in biodiversity?
reduction in species / extinction
what are the possible remedial measure for loss in biodiversity?
monitor it
species conservation
education
international trade agreements
what are the causes of land use change?
change for food and biofuel production, urbanisation and livestock farming
what are the consequences of land use change?
crops grown for export so insufficient crops for local use
reduced biodiversity
what are the possible remedial measure for land use change?
reduce meat consumption
more efficient crops
what are the causes of biogeochemical cycles reaching boundary?
use of fertilisers containing nitrate and phosphates
what are the consequences of biogeochemical cycles reaching boundary?
eutrophication
what are the possible remedial measure for biogeochemical cycles?
reduce use of fertilisers
what are the causes of ozone reaching boundary?
manufacture and use of CFC’s in aerosols/refrigerators
what are the consequences of ozone reaching boundary?
ozone layer destruction
harmful UV rays not absorbed
what are the possible remedial measures to restore ozone layer?
montreal protocol
manufacture and use of CFC’s are banned
what are the causes of ocean acidification?
greenhouse gases from burning fossil fuels
CO2 dissolves in seawater forming H2CO3 which releases H+ ions
what are the consequences of ocean acidification?
low pH causes calcium carbonate to leach out of corals/shells/exoskeletons so softer shells so organisms are more vulnerable
what are the possible remedial measure for ocean acidification?
reduce fossil fuel use
what are the causes of change in freshwater use?
increased water use for irrigation and industry
climate change
pollution of water
change in land use
what are the consequences of change in freshwater use?
reduction in freshwater availability
what are the possible remedial measure for change in freshwater use?
stop irrigation of non food crops
reclaim waste water from industry
use desalinated water
what are the causes of aerosol boundary being crossed?
atmosphere contains minute particles (ash + soot) from combustion and coal power stations
what are the consequences of aerosol boundary being crossed?
increased respiratory problems and lung cancer
can build up on leaves and reduce photosynthesis
what are the causes of novel entities boundary being crossed?
inorganic pollutants
synthetic organic pollutants
what are the consequences of novel entities boundary being crossed?
bioaccumulation in food chains
what are the possible remedial measure for novel entities?
banning
what is biodiversity?
number of species and individuals of each species in a given place at a given time
what are endangered species?
a species that is at risk of extinction
what are extinct species?
a species that has no living members
what are reasons for extinction?
natural selection
non contiguous populations
habitat destruction
pollution and oil spills
overhunting
competition from introduced species
how does natural selection cause extinction?
human activities causing habitats to change faster than new mutations allow species to adapt
what are non contiguous populations?
groups become isolated from each other so cannot interbreed so less genetic diversity for a healthy population
why is conservation important?
for food
aesthetic
medicine
keystone species (ecosystems would fail without them)
building materials
how can we conserve?
protected areas
education
legislation to protect habitats and enhance biodiversity
trade agreements
breeding programs
seed/sperm banks
reintroduction
ecotourism
what is agricultural exploitation?
hedgerows removed to make larger fields
more fertilisers causes eutrophication
what are the problems caused by deforestation?
causes soil erosion
causes droughts / lowland flooding
habitat destruction
contributes to global warming
what are forest management plans?
coppicing
selective cutting
long rotation times
what is coppicing?
tree trunk is cut
leaves stool
shoots can still emerge
can be cut on rotation to provide timber of different widths
what is selective cutting?
removing some trees rather than all trees at same time so soil is less vulnerable to erosion
what are overfishing problems?
small nets catch fish before they are sexually mature
large nets catch non target fish
trawlers drag nets through water and damage ocean beds causes habitat loss
what are ways to reduce overfishing?
larger net size
quotas
exclusion zones restrict fishing in breeding areas
legislation controlling size of fleets
consumers can choose to eat sustainable fish or less fished species
fish farming
what are the disadvantages of fish farming?
parasites and disease spread quickly
fish waste and waste food cause eutrophication
fish can escape and outcompete native wild fish
farmed fish are often fed with other fish
why is environmental monitoring important?
avoid losses in biodiversity
retain species diverse areas free from development
halt any changes that might bring about species loss
why should scientists be involved in decisions?
able to analyse and evaluate data
they should be independent and not under financial pressure to implement changes
what are environmental countermeasures?
re-routing roads to avoid areas of high biodiversity
avoiding wind turbines in Hird bird areas
tunnels under roads for hedgehogs etc
identify future needs
erecting rest boxes
green bridges linking habitats
why are the conflicts between governments, famers and conservationists?
all have different priorities and under different pressures
