Humans In The Environment Flashcards
Biological diversity (biodiversity)
variety of living organisms with regard
to
genes, species, and ecosystems.
current biodiversity numbers
Currently decreasing at an alarming rate (50 to 500 times the natural
rate of background extinction)
cause of bad biodiversity numbers
human activities
Destruction of natural habitats
Activities that produce acid rain precipitation or pollution
biotic pollution
Unregulated hunting
Commercial harvest- removing organisms from the wild for use
deforestation
biotic pollution
introduction of a foreign species into an area
where it is not native, upsetting the balance of species
term for foreign species–biotic pollution
invasive species
deforestation
temporary or permanent clearing of forests for agriculture or other uses
consequences of deforestation
(IBSI) Increases soil erosion, decreasing soil fertility, loss of biodiversity, Surface runoff flowing into rivers and streams increases global temp, Increase global temperature by releasing carbon store in trees as CO2,
increasing the greenhouse effect, higher CO2 levels
Slash and burn agriculture
farmers cut down trees, allow
them to dry, then burn the area and plant crops in the fertile soil
immediately after burning. Soil productivity declines rapidly
afterward, and farmers must move to a new area and repeat the
whole process
why deforest?
Slash and burn agriculture
Global climate change
Earth’s average surface temperature has increased 1.1
degree F during 20th century
Why are CO2 and other gases
accumulating in the atmosphere?
due to burning of fossil fuels-
coal, oil, gas. Deforestation also leads to
CFC
chlorofluorocarbons
Ozone
O3
what gases aside from CO2 are accumulating in atmosphere
methane, ozone, CFC
greenhouse effect
CO2 and other gases
accumulating in the atmosphere absorb heat in the atmosphere, warming the
atmosphere and ocean
why is it called the greenhouse effect?
Similar to the way glass traps radiation in a greenhouse
What does global climate change lead to?
Change in precipitation patterns, range of habitats, more heat related deaths, Glaciers thawing=change in sea level,
How to improve global climate change
Stabilize CO2 emission
Ozone (define)
Form of oxygen naturally produced in stratosphere, shields surface from uv rays
Stratosphere
Upper part atmosphere
Ozone hole
Over Antarctica where levels decrease every year, been very rapid
What chemical causes ozone hole?
CFCs, used in aerosols, ACs, refrigerators, drift up to stratosphere, broken down by UV rays and release Cl2. Sunlight promotes chemical reaction in which the Cl2 breaks ozone into O2.
Consequences of ozone hole
Harms organisms–humans skin cancer, cataracts, weak immune system, ecosystems disrupted bc it kills algae, may damage crops and forests
Help ozone hole
Reduce CFC
Acid rain production-
Burning of fossil fuels (coal, oil) release pollutants into the air that
contain sulfur dioxide and nitrogen dioxide. these substances react with water and produce sulfuric acid and nitric acid.
how does the acid get to earth (acid rain)
These substances kill plants and animals and lakes, river, and land
when they return to the surface of the Earth through
precipitation
Desertification-
Overgrazing of grasslands that border deserts turn the grasslands into deserts
result of desertification
Agricultural habitats decrease
Natural habitats are lost
biological magnification
As one organism eats another, it becomes more and more concentrated
Where in pollution does biological magnification occur?
DDT
DDT
pesticide
eutrophication
Lake can be polluted with runoff fertilizer or sewage- adding
abundant nutrients.
eutrophication- stimulates
algal blooms
algal blooms
massive growths of algae, which reduce
oxygen supplies through respiration. After they die, they are
consumed by detritivorous bacteria, which further reduces the
oxygen. This causes Oxygen starvation for many animals, and algae blocks the sun, so whole lake dies.
