Transcript Human Impact on the Biosphere

Human Impact on
the Biosphere
Acid Precipitation
• Acid precipitation, acid rain, is when the pH of
precipitation is much lower than normal rain
• Normal rain is mildly acidic at 5.6
• Acid rain has be measured as low as 2 which is
almost 10,000 more acidic that normal rain
• When nitrous and sulfur oxides produced
from burning fossil fuels mix with water in the
atmosphere, nitric or sulfuric acid is produced
Acid Precipitation
• Acid precipitation occurs in industrialized
parts of the world or down wind of these
regions as the pollutants can travel long
distances
• Acid rain and damage building, plants and
change the chemistry of bodies of water
• Long term changes can damage soil and
bodies of water making unable to sustain life
Acid Precipitation
• Reducing industrial and automobile emissions,
would lead to less air pollution and decreased
acid rain
• Burning coal is the primary source of sulfur
oxide entering the atmosphere, so finding
alternative energy sources is a great direction
Climate Change
• Climate change is a normal part of the
patterns of the earth, alternating between ice
ages and warnings
• Sea levels have risen and dropped over the
past 4.54 billion years
Climate Change
• Much evidence shows that we are currently in
a warming cycle, but the concern is that since
the industrial age, humans may be
accelerating this change
• Large amounts of Greenhouse gasses are
being generated by human activity such as
carbon dioxide and methane, which makes the
planet’s overall average temperatures warmer
Climate Change
• Rising sea levels and change in ocean currents
can flood densely populated regions of the
world since the largest percent of the human
population live on or near the coast
• Even if our measurably high levels of
greenhouse gases are not the cause, reduction
of burning fossil fuels and ways to capture
methane waste from cattle can possibly slow
down these changes
Ozone Layer Depletion
• The ozone layer is in the stratosphere and
protects us from ultraviolet (UV) radiation that
can cause mutations and directly damage
plants and other living organisms
• Without the ozone layer life as we know it
would not exist
Ozone Layer Depletion
• The use of chlorofluorocarbons (CFCs) as
propellants and coolants damaged this
protective layer and caused it to thin and
created a large hole over Antarctica
• This has caused higher rates of skin cancer and
damage to crops
• Continued loss of crops could increase famine
and extinction rates on earth
Ozone Layer Depletion
• The Montreal Protocol enacting in 1987 asked
for a voluntary and systematic ban on ozone
damaging chemicals and some recovery of the
ozone layer has already been observed
• The atmospheric levels of CFCs have also
started decreasing since the ban
Invasive Species
• Also called alien, nonnative and introduced
species
• These are species either accidently or
intentionally released into a nonnative habitat
and were more successful than native species
(remember the competitive exclusion principle)
• They can reduce biodiversity in an area
• Kudzu, fire ants and tiger mosquitoes are a few
examples
Invasive Species
• Invasive species are a problem all over the world
were people are or have been
• They replace native species and can lead to
extinctions
• Some species can even significantly change the
local ecosystem
• Identify accidental introductions like ballast water
and infected plant material
• Do not allow nonnative species to be sold as pets
Use of Fossil Fuels
• The three types of fossil fuel are coal, natural
gas and petroleum (oil)
• These carbon rich substances are also rich in
high grade energy, but were underground and
not a active in the carbon cycle on the planet's
surface
• Burning fossil fuels produces large amounts of
air pollution including carbon dioxide, carbon
monoxide, nitrous oxides, sulfur oxides, lead,
mercury, ozone (ground level=bad) and more
Use of Fossil Fuels
• Burning of fossil fuels occurs in factories, most
forms of transportation, farms, for generation
of electricity and heating. Petroleum is used in
100,000s of products from foam cups to
pesticides.
• Air pollution leads to many human health
problems, acid rain, water pollution and habitat
destruction. Plus, biomagnification of lead and
mercury up the food chain.
Use of Fossil Fuels
• Alternative sources of energy
• Substitution for petroleum in the manufacture
of many products
• Reduction of wasteful
packaging materials and
recycling of plastics can
help reduce our carbon
footprint
Overfishing
• 1 billion of the world’s population depends on
fish/seafood as their only source of protein and
main source of food
• Increased use of technology has caused near
extinction of many important species of fish
like cod
• Currently, fishing continues unsustainably
meaning more fish are caught that can replace
themselves
Overfishing
• Widespread loss of these consumers can
devastate marine and freshwater biomes
• Human populations will have to seek of sources
of food
• Enforcing fishing regulations and high quality
aquaculture can take some of the stress off of
wild populations allowing them to recover
Deforestation
• The clearing of forests on a huge scale
• At the current rate, the rain forests of the world
will be gone in 100 years
• Forests are cleared for wood (including fuel
wood and for paper), human population
spread, and agriculture
• Forests are decreasing globally, but the rain
forest are the most threatened
Deforestation
• The rain forests are huge sources of biodiversity
and their loss could prevent discoveries of foods or
medicines that would help the human population
• Continued loss means that large amounts of
carbon dioxide will not be removed from the
atmosphere and less oxygen produced. Extinctions
of forest dwelling organisms and all of the other
natural services that forests provide would be
decreased or loss
• Better management of forests and protection of
key habitats has to happen to enact change
Desertification
• Desertification is the degradation of formerly
productive land into a desert
• Grasslands are the most sensitive, but climate
change, overgrazing of cattle, redirection of
rivers by damming and poorly managed farming
and irrigation techniques can cause these
changes to any ecosystem (the dust bowl?)
• Deserts do not have the biodiversity and
productivity of other biomes
Desertification
• The loss of arable land and local biodiversity
can be devastating for the human population
and the organisms
• Extinctions and further land loss can result for
these environmental changes
• Good irrigation techniques and the use of area
appropriate crops can prevent desertification as
well as employing soil protection regulations
Habitat Loss
• Habitat loss/degradation/destruction is the
changing is an environment so it is no longer
suitable for the native organisms
• Environments change naturally, (remember
succession?), but humans can change areas
quickly by building, polluting and agriculture
• Even small environmental changes can cause
the loss of some of the native species
Habitat Loss
• Habitat loss/degradation/destruction can then lead
to significant loss of productivity and loss of those
primary producers always causes losses up the
food chain
• Without proper management of environments,
especially highly productive areas like estuaries
and rain forests can be lost
• The human population has to remember that we
are part of nature and should be steward of the
earth as even renewable resources must ne used
sustainably..
DDT Use
In 1950's The World Health Organization (WHO) financed and supported
the first ever team of over 14,000 parachuting cats into Borneo. It was
early in the 1950's, the Dayak people of Borneo tragically suffered an
outbreak of malaria, spread by mosquitoes. The World Health
Organization (WHO), without thinking through all the consequences,
liberally sprayed the area with DDT to kill the mosquitoes. The
mosquitoes died, malaria lessened and the people of Borneo were happy.
Then roofs started to collapse and the people of Borneo were sad. It
appeared that a parasitic wasp had previously been keeping a thatcheating caterpillar under control and the DDT killed the wasps, meaning
the caterpillars were having a field day. Tragically various poisoned insects
were eaten by geckoes, which were eaten by cats and many cats died.
The people of Borneo missed their cats greatly and asked WHO to help
repair the damage it had done. WHO talked to some of their feline
experts who proposed that 14,000 cats should sky dive into Borneo, in
order to help the grieving residents, who longed to have their feline
company once more. WHO also thought it might help with the massive
outbreak of rats, which were spreading typhus and plague. WHO initiated
Operation Cat Drop and the cats started parachuting. Then the rat
population declined and the people of Borneo were happy once more.
Water Pollution &
Eutrophication
• Pollution he degrading of water quality and
eutrophication is the when excess nutrients
enter bodies of water causing rapid growth of
plants or algae
• Runoff of animal waste and or fertilizers
accelerate eutrophication and can lead to
toxic algal blooms causing fish kills and
impacting human health
Water Pollution &
Eutrophication
• Pollution and eutrophication can devastate
the aquatic and local terrestrial environment
leading to water unfit for use by most
organisms except for some detritivores and
decomposers
• Continues mismanagement of water can lead
to further unavailability of water to our
growing population
• Education and better management to protect
our limited water supply is essential