1. The Precautionary Principle IB Topic 5.2

2. 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?

3. IPCC Findings  2007; their 4 th 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

4. 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

5. Without the precautionary principle …  Industries and consumers tend to proceed with their activities until it’s obvious harm is being done  With irrefutable proof, activity is usually taken to reduce the activity in question

6. Example  The use of DDT pesticide  Prohibited in North America  Proven to accumulate in ecosystems  Reduce populations of birds of prey Bald eagle

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

8. 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

9. 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?

10. 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?

11. 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

12. 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

13. 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?

14. 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

15. In conclusion  Carbon is a super important element to the biosphere Must be recycled Levels are affected by:  Photosynthesis  Respiration  Combustion  Feeding  Decomposition  Earth’s natural greenhouse is essential for life  It’s just intensifying Human activity Carbon dioxide, methane

16. For your test tomorrow  5.2  Draw and label the carbon cycle How does carbon enter? Leave?  Analyze changes in CO 2 concentration  Explain the greenhouse effect  Outline the precautionary principle