Human Impact on the Biosphere

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Human Impact on the Biosphere
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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

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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

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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

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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

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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 planets
  overall average temperatures warmer

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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

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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

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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

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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

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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

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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

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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 levelbad) and more

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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.

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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

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Overfishing

• 1 billion of the worlds 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

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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

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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

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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

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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

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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

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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

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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..

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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
  thatch-eating 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.

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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

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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