1. Climate Change

2. BEFORE WE BEGIN………..

3. This is a controversial subject. There is lots of good and not so good information that promotes differing points of view on the subject. We will be looking at some of these in detail.

4. Climate change. Why should we care? The climate has been changing since the beginning of Earth. Why is it a problem all of a sudden?

5. Earth’s temperature over the last 600 million years:

6. Look!!! It’s cold now!!! Of course we are going to get warmer. IT’S ALL NATURAL CYCLES !!!

7. Climate change over the last 425000 years.

8. Look!!! It gets warm then cold then warm then cold then warm. AHHH! We’re heading for another ice age! Good thing there’s global warming!

9. Yes, the climate does change naturally. Plate tectonics Volcanoes Meteorite impacts Sun cycles Changes in Earth’s tilt and orbit……

10. Yes, the climate does change naturally. Plate tectonics Volcanoes Meteorite impacts Sun cycles Changes in Earth’s tilt and orbit…… HOWEVER………..

11. What you need to understand in order to engage in intelligent discussion about climate change: Earth’s temperature in the Holocene (last 10000 years)

12. We have been very lucky to have a long stretch of time that has very little climatic change!

13. Consistent temperatures make it easier for ecosystems to develop. The ecosystems we have on Earth today are strong because they have been able to adapt to their environment for the last 10000 years. This consistent temperature is very good for ecosystems, and it’s good for the people who rely on those ecosystems.

14. If left alone, the consistent Holocene climate should last for several thousand years into the future. (Berger, A. & Loutre, M. F. Science 297, 1287–1288 ) http://www.sciencemag.org/content/297/5585/1287.full

15. So….. Having a consistent climate is a good thing (for us) We have a forecast of a consistent climate for the next few thousand years

16. Why is this happening?

17. At any point you are welcome to introduce any new information from respected peer-reviewed journals.

18. The introduction of this unit will be:

19. Before we begin.... This was meant as a film to introduce the idea of climate change. It is meant for the general public.

20. Also note: There is a lot of criticism about the information shown in this film, some of which valid. We will be looking at critical perspectives after watching the film.

21. http://www.56.com/u69/v_NDU0Mzk2NTA.html

22. http://video.sina.com.cn/v/b/26197272- 1068641897.html

23. Terminology to know: IPCC: Intergovernmental Panel on Climate Change

24. The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for the assessment of climate change. It was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) to provide the world with a clear scientific view on the current state of knowledge in climate change and its potential environmental and socio- economic impacts. The UN General Assembly endorsed the action by WMO and UNEP in jointly establishing the IPCC.

25. Reputable specialist who study climate change. Endorsed by the UN (United Nations)

26. Controversy after the film. The film was shown in the United Kingdom. A student's parents didn't like the film being shown in school so they challenged the content of the film in court. The court found 9 things that they did not think were correct.

27. http://en.wikipedia.org/wiki/Dimmock_v_Secreta ry_of_State_for_Education_and_Skills#The_nin e_inaccuracies http://en.wikipedia.org/wiki/Dimmock_v_Secreta ry_of_State_for_Education_and_Skills#The_nin e_inaccuracies http://www.carbonpositive.net/viewarticle.aspx? articleID=1306 http://www.carbonpositive.net/viewarticle.aspx? articleID=1306

29. Sea levels probably won't rise by 7 metres anytime soon according to the IPCC we are probably heading towards about a 59cm rise by 2100 2012 update: the projection now is for about a 1m – 1.4 m rise by 2100. ( http://www.pnas.org/content/early/2009/12/04/0907765106.full.pdf)

31. A 1 meter rise in ocean levels would create a very difficult situation for low lying cities. http://www.grida.no/graphicslib/detail/population- area-and-economy-affected-by-a-1-m-sea-level- rise-global-and-regional-estimates-based-on- todays-situation_d4fe

32. Pacific islands are being evacuated. Maldives is buying land so they can move.

33. Mount Kilimanjaro may be melting for other reasons nobody knows for sure how the polar bears drowned lake Chad was a combination of irrigation for farming and climate change.

34. http://www.skepticalscience.com/al-gore- inconvenient-truth-errors.htm http://www.skepticalscience.com/al-gore- inconvenient-truth-errors.htm

35. Does this mean everything in the film is false?

36. The Main Claims made by the film:

37. The planet is getting warmer

38. True, This is easily verifiable.

39. The best explanation for why the planet is warming is the increase in greenhouse gases, (mostly CO2) in the atmosphere.

40. The best explanation for why the planet is warming is the increase in greenhouse gasses, (mostly CO2) in the atmosphere. True, this is consistent with the overwhelming scientific consensus

41. Global warming will increase the chance of extreme weather (stronger hurricanes, more rain and floods in wetter places, more drought in dryer areas)

42. Global warming will increase the chance of extreme weather (stronger hurricanes, more rain and floods in wetter places, more drought in dryer areas, longer forest fire seasons) True, This is verifiable

43. In the end The court ruled: “Al Gore's presentation of the causes and likely effects of climate change in the film was broadly accurate."

44. The Greenhouse effect This is probably what you have learned before:

45. This is more realistic:

47. 1. Simple: Greenhouse gases act as an insulating “blanket,” making it harder for energy to escape and resulting in the warming of the surface until its higher temperature can still force enough energy through to maintain energy balance.

48. More sophisticated: Greenhouse gases absorb outgoing infrared and heat up. They re-radiate their energy both upward to space and downward to the surface. The surface is warmed by this back radiation and, therefore, radiates more infrared to maintain energy balance.

49. Most sophisticated: The upper atmosphere, being cooler than Earth’s surface, can’t emit as much radiation as the surface. Radiation from the atmosphere alone, then, can’t keep the planet in energy balance. Therefore, the surface temperature must be higher than the atmosphere temperature to provide enough additional radiation that can escape through the nearly but not completely opaque greenhouse gases. Thus, the greenhouse effect depends crucially on the temperature difference between surface and upper atmosphere. Increasing greenhouse warming actually entails cooling the upper atmosphere.

50. Note that there has always naturally been some CO2 in the atmosphere. Before fossil fuels were burnt it was about 280ppm.

51. PPM: Parts per million.

52. If there were no greenhouse gases the world would be much colder. Probably be about 30 degrees colder.

53. So... greenhouse gases keep the world at a comfortable temperature for us.

54. However..... In recent years we have been using a lot of fossil fuel. Carbon that has been trapped underground for hundreds of millions of years (mostly from the Carboniferous Period) is now being released into our biosphere.

56. http://co2now.org/ We are now at about 396 ppm. This is far more than has been in the atmosphere in all of human history.

58. The problem is that there is more greenhouse gas in the atmosphere now than ever before in human history. This will very predictably cause a change in global temperature.