1 / 56

Climate: What we know about it, How we know about it, and What we’re doing to it.]

Climate: What we know about it, How we know about it, and What we’re doing to it.]. CO 2 and the Greenhouse Effect. CO2 concentrations between 1995 and 1990. CO2 concentrations in ice cores 1000 to 2000 AD. global view: CO2 concentrations 1000 to 2000 AD.

hartwell-carl
Download Presentation

Climate: What we know about it, How we know about it, and What we’re doing to it.]

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Climate: What we know about it, How we know about it, and What we’re doing to it.]

  2. CO2 and the Greenhouse Effect CO2 concentrations between 1995 and 1990

  3. CO2 concentrations in ice cores 1000 to 2000 AD

  4. global view: CO2 concentrations 1000 to 2000 AD. Note change during industrial revolution!

  5. Antarctica Global

  6. How the Greenhouse effect works 1. Different frequencies of light act differently • Greenhouse Gasses in Earth’s atmosphere trap • infrared light (heat) Same process that makes your car warm on a cold winter day, or heats up a Greenhouse!

  7. Most of the radiant energy from the sun is concentrated in the visible and near-visible parts of the spectrum. The narrow band of visible light, between 400 and 700 nm, represents 43% of the total radiant energy emitted.

  8. What are the major Greenhouse Gasses? Water, Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (N2O), Fuorocarbons (CFCs)

  9. Greenhouse Effect The rise in temperature that the Earth experiences because certain gases in the atmosphere trap energy from the sun. Without these gases, heat would escape back into space and Earth’s average temperature would be about 60ºF colder. Because of how they warm our planet, these gases are referred to as greenhouse gases. Gases include: water vapor, carbon dioxide, nitrous oxide, and methane Trace greenhouse gases are relatively transparent to incoming visible light from the sun, yet opaque to the energy radiated from the earth.

  10. Northern Hemisphere Temperature since 1900 A.D.

  11. Northern Hemisphere Temperature since 1400 A.D.

  12. Temperature Carbon Dioxide

  13. What does the future hold? • What is “climate variability”? • What is “interannual climate variability?” • Why is it important? • What can we learn about past climate? • How are our activities impacting climate?

  14. Climate varies on long (millennial) timescales

  15. Climate varies on short (interannual) timescales

  16. Why is understanding interannual variability important? 1) It is necessary if we are going to make a reasonable prediction of future climate.

  17. Why is understanding interannual variability important? 2) It provides a framework for understanding variability in other systems.

  18. The Pacific Decadal Oscillation Sea surface temperatures.

  19. Time for a movie!

  20. The isotope paleothermometer • The d18O isotope ratio in water is influenced by temperature – both during evaporation of H2O from the ocean and its eventual precipitation on land as rain or snow. • At high latitudes, there is a very strong, approximately linear relationship between d18O and local temperature.

  21. What is “delta 18 O”? The ratio of 18O/16O in ice is compared to the ratio of 18O/16O in average ocean water. This comparison is called 18O. Variations in the 18O of the oxygen in the water molecule, H2O, is used in climate studies

  22. Why does d18O relate to temperature? This equilibrium is temperature dependent The O18/O16 ratio provides an accurate record of ancient water temperature.

  23. Worldwide Ice Core Sites

  24. Mt. Logan, Yukon (Canada)

  25. What can we learn about interannual climate variability from ice cores?

  26. Annual layers in glacier ice

  27. Central England temperature estimates “Medieval warm period” “Little ice age” After Lamb, 1982

  28. Ice core data: trends removed r =+ .52

  29. Siple – 1400-1983

  30. Siple Dome- 1900-1996

  31. Abrupt Climate Change End of the “Younger Dryas” took <50 years

  32. Instrumental data (thermometers!) “Proxy” data (tree rings, ice cores, corals)

  33. Central Greenland temperatures 10-year average temperatures from the GISP2 ice core

  34. Central Greenland d18O

  35. The GISP2 ice core record

  36. Northern Hemisphere Temperature since 1400 A.D.

  37. Ice coring sites Queen Maud Land Siple Siple Dome

  38. Spatial covariance of Antarctic temperature with PC1

  39. Antarctic T trends since 1982 AVHRR (infrared) satellite observations

  40. Queen Maud Land Siple Dome Siple

  41. What to do next? A good example is how Society dealt with the Ozone Hole

More Related