Geography 1001: Climate & Vegetation

1. Geography 1001:Climate & Vegetation Instructor: Andrés Holz Teaching Assistant: Eungul Lee

2. Agenda for Lecture 13: Thursday June 29 • Announcements • Yesterday’s lecture is online • First reading for guest lecture is also online • FIELD TRIP TO ISABELLE LAKE, INDIAN PEAKS • Objective • MEET AT THE REC CENTER TURN AROUND AT 9 AM. WE WILL DEPART PROMPTLY.

3. Agenda for Lecture 13: Thursday June 29 • Gear Requirements: • hiking boots (the trail is muddy in places and there is still some snow on the ground) • raingear • sun block & chap stick • Sunglasses hat, gloves • warm layers (fleece) • notebook and pen to take notes

4. FIELD TRIP TO ISABELLE LAKE, INDIAN PEAKS

5. Access and Trail Description: • Lake Isabelle is one of the more beautiful trails in the Front Range. • The lake lies near timberline in a dramatic valley, offering views of high peaks such as Shoshone, Apache and Navajo Peaks • Distance: 2.0 miles one-wayLake elevation: 10,868 feetTrailhead elevation: 10,480 feetNet elevation gain: 388 feet

6. Agenda for Lecture 13: Thursday June 29 • Today’s lecture: • Historical development of the ecosphere • Biological processes that changed the atmosphere • Anaerobic respiration • Photosynthesis • Aerobic respiration • Atmospheric changes • Increase O & N • Stabilization of CO2 • O3 layer

7. Agenda for Lecture 13: Thursday June 29 • Today’s lecture: • A bit of ourselves • DNA • Earth colonization • Changes on earth • Milanković

8. Be aware of.. • How the Ecosphere have developed over time: Timeline and processes occurring • How Climate & Life on earth have co-evolved • The fact that regardless of co-evolution, we still have large scale climate changes Milanković Theory

9. A bit of history here…

14. 500 million years ago..

15. 400 million years ago..

16. 300 million years ago..

17. 200 million years ago..

18. 100 million years ago..

19. 50 million years ago..

20. 1 million year ago..

21. Less than a million year ago.. • So far, we know that the Earth has experienced at least 8 ice ages • Last one?

22. Today • If we think of the earth life being a calendar year • (i.e. from Jan 1 to Dec 31), when do you think we appeared?

23. But how have the conditions for life changed over these 4 billion years? The solar system form 4.6 billion years ago. 4 billion years ago, the atmosphere was made of from volcanic emissions

24. TIME 4 billion yrs ago PROCESS Water vapor Ammonia (NH3) Methane (CH4) Hydrogen sulfide (H2S) Hydrogen gas (H2) Carbon monoxide (CO) **Very little O2 & N2 All water was held in the atmosphere as vapor because of high temperatures (water vapor greenhouse effect).

25. TIME 4 billion yrs ago 3.1-3.5 billion yrs ago PROCESS H2O, CO2, (N) dominant. CO2, H2O, N2 dominant O2 begins to accumulate. Cooling of the atmosphere causes precipitation and the development of the oceans. Break of H2O by ultraviolet rays H2O  O2 + H Water vapor clouds common in the lower atmosphere. First single cell algae & bacteria

26. TIME 3.1-3.5 billion yrs ago PROCESS Anaerobic respiration • Single cells algae were able to • produce Energy without O2 • Take C-H20 (simple organic molecules food) & break down into CO2 + alcohols energy For ~800 millions of years, CO2 was released (as by-products of respiration) & built up in the atmosphere and oceans There was enough CO2 in the atmosphere to sustain life….

27. PROCESS • Photosynthesis Single-cells (blue-green algae have chlorophyll) • TIME • 2.3 billion yrs ago…. sunlight CO2 + H2O CH2O + O2 built up food • energy • Initially, the released O2 was lethal • to the living organisms

29. PROCESS • Ozone (O3) layer is being built in the stratosphere • TIME • 1.9 billion yrs ago…. • Filters out the UV radiation make life possible on land development of O2 tolerant organisms

30. Aerobic life on the land took longer to start because it could only occurred after the ozone layer was formed

31. PROCESS • Aerobic respiration • TIME • 1.3 billion yrs ago…. CH2O + O2 CO2 + H2O • energy

32. PROCESS • Life is widespread in the oceans • Single cells • Early fishes • Large algae • TIME • 600 mill yrs ago….

33. PROCESS • Life is widespread on lands • Earliest plants • Invertebrates • Vertebrates • TIME • 420 mill yrs ago….

34. PROCESS • Development of tropical rainforest • fossil fuel  today’s oil • TIME • 350 mill yrs ago….

35. PROCESS • Colonization of larger vertebrates • TIME • 200 mill yrs ago….

36. A bit of ourselves..

37. Date of Separation according to Mitochondrial DNA

38. Early Human Phylogeny Asia Africa Asia Europe eastern Africa Africa? southern Africa Europe & W Asia eastern Africa

39. Expansion of Human Habitat(old theory)

40. At 18,000 years ago, the Earth looked like this map from Earth and Life Through Time

41. Food Chain of Land Animals

42. World Population Trend from 10,000 B.C. to 200 A.D.

43. First civilization collapse.. • Eastern Island • Mayas Empire

44. UN, World Population Prospects:1992

45. Why has climate change? • Meteorite impacts (very infrequent & random) • Hugh Volcanic eruptions (more frequent, but still random) • Enough evidence of glacial and interglacial periods for the last 2-3 mill yrs • Hypotheses, Theories, & Laws…the same?

46. Milanković cycles (Theory) Performed detailed calculations concerning the periodicity of the earth’s orbital parameters • Precession • Axial tilt • Eccentricity

48. Eccentricity • During periods of high eccentricity higher differences between max & min distance from sun to earth more potential for extreme (cold & warm) climate

49. Orbit eccentricity

50. Tilt angle (or obliquity)