1. Observed Global Climate Change

2. Review of last lecture Tropical climate: Mean state: The two basic regions of SST? Which region has stronger rainfall? What is the Walker circulation? Mean state: Two types of ocean upwelling, ocean-atmosphere feedback El Nino and La Nina: Which region has warm SST anomaly during El Nino? 4-year period. Land-sea contrasts: seasonal monsoon Extratropical climate: Mean state: westerly winds, polar vortex What is the primary way El Nino affect extratropics? (PNA) The oscillations associated with strengthening/weakening of polar vortex: AO, AAO

3. The Intergovernmental Panel on Climate Change (IPCC) is organized by the World Meteorological Organization, and endorsed by the United Nations General Assembly. This is a worldwide enterprise that includes literally thousands of scientists that are involved in producing and critiquing a definitive statement on climate change. The political controversies have centered around condensed summaries produced for policy makers. We have had 5 assessments by IPCC so far. First Assessment Report (1990) Second Assessment Report (1995) Third Assessment Report (2001) Fourth Assessment Report (2007): Nobel Peace Prize Fifth Assessment Report (2013-2014) How is scientific consensus achieved on global warming?

4. How do human activities change the global climate? Human beings are changing the global climate system in three different ways: Release or cleanse greenhouse gases Release or cleanse pollutants (aerosols) Change land cover (deforestation and urbanization)

5. The most common atmospheric circulation structure L H H L Heating Cooling or No Heating Imbalance of heating  Imbalance of temperature  Imbalance of pressure  Wind Radiation Convection Conduction Latent/Sensible Biosphere Land/Ocean/Ice/Stra tosphere Feedback Greenhouse Gases Pollution Clouds Precipitation (Latent heat) Spiritual Social Health Economy

6. Observed change of greenhouse gases Global atmospheric concentrations of CO 2 and CH 4 have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values determined from ice core measurements spanning the last 650,000 years!

7. Radiative heating of greenhouse gases

8. Source of greenhouse gases CO 2 fossil fuel use is the dominant cause of CO 2 increase

9. GHG Emissions by Sector

10. Greenhouse gas emissions per capita The developed countries and developing countries contribute almost equally to the emissions of GHGs.

11. Video: A global warning? https://www.youtube.com/watch?v=t_miunplJK4 https://www.youtube.com/watch?v=t_miunplJK4

12. Observed Change in Global Temperature: Significant warming

13. Global map of temperature change: Largest warming in Arctic (“Arctic amplification”) Larger warming over land than ocean

14. Global map of snow/ice cover

15. Observed Melting of Arctic Sea Ice http://arctic.atmos.uiuc.edu/cryosphere/m ultiyear.ice.quikscat.mov

16. Melting of Greenland Ice Sheet – A huge contributor to sea level rise today Greenland is responsible for about 10% of the observed global sea level rise and accelerating. Greenland holds 7 m of sea level equivalent.

17. Observed Changes in Snow Cover: Significant melting

18. Melting of Mountain Glaciers: a major contributor to sea level rise IPCC (2001) Glacier retreat is a world-wide phenomena. Will affect water supply for millions: Kenya/Tanzania Northern India Andes Mountains

19. 19172008 19782004 Qori Kalis Glacier, Peru Pedersen Glacier, Kenai Fjords National Park, Alaska Pasterze Glacier, Austria 18752004

20. Observed Changes in Global Sea Level

21. Observed Changes in Sea Level Largest in the western part of ocean basin

22. Summary: Observed significant changes

23. Change in Mean vs Change in Extremes

24. Observed changes in precipitation extremes: Increased contribution from very wet days

26. Summary: Observed significant changes in extreme weather

27. Summary 3 ways human activities affect the climate. Rapid increase of greenhouse gases (CO 2, CH 4, N 2 O) since 1750: far exceed pre-industrial values determined from ice core measurements spanning the last 650,000 years, which is mainly caused by CO 2 fossil fuel use. Lead to strong radiative heating. The developed countries and developing countries contribute almost equally to the emissions of GHGs. Observed change of mean: air temperature, ocean temperature, melting of arctic sea ice, Greenland ice sheet, snow and glaciers, rising of sea level. Observed change of extreme events: extreme precipitation events, heat waves, strongest hurricanes

28. Works cited http://www.earthtimes.org/environment/greenhouse-gases/ National Snow & Ice Data Center http://sciencewithme.com/learn-about-global-warming/ http://www.chemistryland.com/CHM107Lab/Exp04_biodiesel/BiodieselLab/Exp4 Biodiesel.htmlhttp://www.chemistryland.com/CHM107Lab/Exp04_biodiesel/BiodieselLab/Exp4 Biodiesel.html http://www.eea.europa.eu/data-and-maps/indicators/greenland-ice- sheet/greenland-ice-sheet-assessment-publishedhttp://www.eea.europa.eu/data-and-maps/indicators/greenland-ice- sheet/greenland-ice-sheet-assessment-published http://arctic.atmos.uiuc.edu/cryosphere/ http://www.treehugger.com/clean-technology/yahoos-5-stunning-before-and- after-pictures-of-melting-glaciers.htmlhttp://www.treehugger.com/clean-technology/yahoos-5-stunning-before-and- after-pictures-of-melting-glaciers.html http://www.detectingdesign.com/ancientice.html http://nca2009.globalchange.gov/human-health http://latino.foxnews.com/latino/news/2012/10/30/hurricane-sandy-floods-new- york-city-photos-show-devastation/http://latino.foxnews.com/latino/news/2012/10/30/hurricane-sandy-floods-new- york-city-photos-show-devastation/ http://ocean.nationalgeographic.com/ocean/critical-issues-sea-level-rise/ http://www.star.nesdis.noaa.gov/smcd/emb/snow/HTML/multisensor_global_sn ow_ice.htmlhttp://www.star.nesdis.noaa.gov/smcd/emb/snow/HTML/multisensor_global_sn ow_ice.html