The Precautionary Principle

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The Precautionary Principle

• IB Topic 5.2

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The precautionary principle

• The Intergovernmental Panel on Climate Change
  (IPCC)
• Created in 1988
• Find out if human activities have an impact on
  climate
• What do you think they found?

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IPCC Findings

• 2007 their 4th report showed that
• Global temperatures are increasing
• Global warming is not a hypothesis but a
  confirmed reality
• There is a 90 chance increasing temperatures are
  due to production of greenhouse gases by human
  activity
• Less than 5 chance due to natural causes
• Within the next 100 years, sea level is expected
  to rise between 18 cm-59 cm
• Likely severe weather will increase
• Heat waves, droughts, heavy rains

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Warning signs lead experts to evoke the
precautionary principle

• Ethical theory
• Action should be taken to prevent harm even if
  there is not sufficient data to prove the
  activity will have severe negative consequences
• Also, if people choose to engage in an activity
  that may cause changes in the environment, they
  must first prove it will do no harm

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Without the precautionary principle

• Industries and consumers tend to proceed with
  their activities until its obvious harm is being
  done
• With irrefutable proof, activity is usually taken
  to reduce the activity in question

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Example

• The use of DDT
• pesticide
• Prohibited in North America
• Proven to accumulate in ecosystems
• Reduce populations of birds of prey
• Bald eagle

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Evaluating the principle

• Tenets of the precautionary principle say
  preventative action should be taken now
• Reduce greenhouse emissions/gas
• Before its too late
• Also say those who wish to continue producing
  excess greenhouse gases
• Should prove that there are no harmful effects
  before continuing

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The other side of the argument

• Farmers, manufacturers, transportation providers,
  among others, wonder
• Why invest in new techniques to reduce
  greenhouse emissions if scientists are not 100
  sure how an enhanced greenhouse effect is going
  to be harmful to the environment

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So,

• Unless preventative measures are taken across the
  board by countries world wide
• There will always be polluting competitors who
  can offer products at a lower price
• Capital vs. ecological measures
• Well informed consumers?
• Choose eco-friendly products
• What message does this send to companies?
• Are we seeing this today?

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Turn and talk

• Suppose you want to buy a particular product.
  You find what you want and the labeling says it
  is produced using eco-friendly techniques. But
  it costs 25 more than a similar product which is
  not eco-friendly. Which would you buy? Why?

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Prevention is better than cure

• Is money spent now on protective measures wasted
  money?
• Is it less expensive to prevent a problem than to
  fix it?
• In most cases yes
• We see this in health care, too
• Cheaper to screen for a disease, educate people
  than to pay for treatment repercussions
• Obesity
• 100 billion is spent annually on obesity
  related issues in the US

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Human impact on Arctic ecosystems

• Parts of North America, Greenland, Iceland,
  Norway, and Russia
• Changes
• More ice melting/year
• Less snow more frozen rain
• Mosquitoes!?
• Woody shrubs ? warmer soil
• Robins
• New species new pathogens

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Consequences in the Arctic

• Changing ecosystems
• Intact ice allow algae to grow (attach to
  underside, transparent to light, allow for
  photosynthesis)
• Ice melting less surface to stick to
• Less algae (producers) what happens to other
  trophic levels?

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And the polar bears

• Long swims need ice to rest
• Rely on seals as main food source
• Hunting techniques to stand on ice near a hole
  and wait for seals to come up for air
• Less ice what happens to this technique?
• Less food
• Cub population has decreased by 10 over the past
  20 years

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In conclusion

• Carbon is a super important element to the
  biosphere
• Must be recycled
• Levels are affected by
• Photosynthesis
• Respiration
• Combustion
• Feeding
• Decomposition
• Earths natural greenhouse is essential for life
• Its just intensifying
• Human activity
• Carbon dioxide, methane

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For your test tomorrow

• 5.2
• Draw and label the carbon cycle
• How does carbon enter? Leave?
• Analyze changes in CO2 concentration
• Explain the greenhouse effect
• Outline the precautionary principle