Climate Change

1. Climate Change

2. Weather vs. Climate • The earth’s climate is dependent on the weather over a long period of time.

3. Weather is what is happening now or in the near future. Weather includes: temperature, rainfall, wind & humidity.

4. Climate refers to the average weather over a long period of time.

5. Climate Variability • Variability is the changes that occur in daily temperature & precipitation.

6. Although an area's climate is always changing, the changes do not usually occur on a time scale that's immediately detectable to us.

7. Weather patterns and climate types take similar elements into account, the most important of which are:

8. The temperature of the air • The humidityof the air

9. The type and amount of cloudiness • Air pressure • Wind speed and direction

10. Although weather and climate are different, they are very much interrelated.

11. A change in one weather element often produces changesin the others and in the region's climate.

12. For example, if the average temperature over a region increases significantly, it can affect the amount of cloudiness as well as the type and amount of precipitation that occur. If these changes occur over long periods of time, the average climate values for these elements will also be affected.

13. Good and accurate weather records have only been recorded for the last 130years.

14. Scientists use the following techniques to find the climate of the earth’s past.

15. Clues in the ice– • looking for tiny air bubbles that form when greenhouse gasses are emitted

16. Also looking for soot particles to indicate when forest fires happened

17. Clues in Sediment • Often have stored pollen grain, plant parts that grew in the past

18. Clues in tree rings

19. All of these methods provide clues to past temperature, precipitation, and wind patterns as well as the chemical make-up of the atmosphere.

20. Greenhouse Gas Effect • Greenhouses are structures that are designed to hold in heat.

21. Greenhouse Gas Effect • The heat-trapping ability of a greenhouse is influenced by several factors:

22. 1. Transparency of the greenhouse cover

23. 2. Colorof inside surfaces

24. 3. Types of surfaces on the inside

25. The earth’s atmosphere acts like an insulating blanket that is just the right thickness.

26. The “blanket” is a collection of atmospheric gases called greenhouse gases that trap heat just like the glass walls of a greenhouse.

27. While the earth’s temperature is dependent upon the greenhouse-like action, the amount of heating & cooling are also influenced by several factors:

28. Type of surface that the sunlight first encounter Forests, grasslands, ocean, ice caps, deserts & cities all absorb and reflect light differently

29. Sunlight falling on white glaciers will strongly reflect back into space.

30. Sunlight falling on a dark desert soil is absorbed.

31. Cloud cover

32. Greenhouses Gases • any gas in the atmosphere capable of absorbing infrared radiation (heat) reflected from the earth’ssurface

33. Carbon dioxide • Sources: • Burning fossil fuels • plant matter • Deforestation • volcanic eruptions

34. Water Vapor • Source: • Evaporation (water cycle)

35. Nitrous Oxide • Sources: • Fertilizer production • burning fossil fuels & wood • agricultural soil (nitrification & denitrification)

36. Methane • Sources: • Decomposition • livestockwaste • decomposing waste in landfills

37. CFCs • Sources: • Manufacturing & industrial processes

38. Global Warming vs. Climate Change • Global warming: trend towards increasing temperatures. 10 warmest years on record have occurred since 1990. • Global climate change: changes in precipitation, temperatures, storm intensity. Global warming can lead to global climate change.

39. Proof…. • 20th century was hottest on record • Since 1861, average global temperature has risen between 1o- 1.4o F (most of that has been since 1980) • 16 hottest years on record have been since 1980, 10 hottest have been since 1990. • Glaciers and sea ice are shrinking. • Sea level rising (4 to 8 inches)

40. 2003 1979 Artic sea ice changes

41. Factors affecting Earth’s temps • Oceans can store heat and CO2, but no one knows how much. • Cloud cover: can warm by trapping and releasing heat or cool by reflecting heat back to space (albedo effect)!

42. Factors affecting Earth’s temps • Outdoor air pollution: aerosols can either warm or cool the atmosphere (much like clouds)

43. Factors affecting Earth’s temps • Stimulate photosynthesis: more CO2 can temporarily cause higher photosynthesis. Temporary because plants will “level off” and die, releasing their CO2

44. Factors affecting Earth’s temps • Methanetrapped under ice is released when the ice melts.

45. Implications of Climate Change

46. Implications: • Plant growth changes • Water supply • Diseases

47. 4) Soil quality 5) Displaced pollution 6) Droughts/Floods 7) Glaciers melting 8) Sea levels rising

48. 9) Warmer water temps 10) Coralbleaching • Algae & coral are losing their bright colors…b/c the algae aredying from the warm temps.

49. 10) Ocean acidity 11) Migration patterns 12) Food production 13) Desertification • An area experiencing desert like condition… lack of water, etc.

50. How can we respond?