1. Introduction to Global Warming Jagadish Shukla Lecture 1, 31 Aug 2010 CLIM 101: Global Warming: Weather, Climate and Society

2. Outline Introduction to Global Warming 1.What is Global Warming? 2.What is Greenhouse Effect? 3.Observed Changes in Climate 4.Observed Changes in Greenhouse Gases (GHG) 5.Hypothesis: Increases in GHG cause Global Warming 6.Testing hypothesis: IPCC 7.Projections of Climate Change 8.Global Carbon Dioxide (CO 2 ) Emissions 9.Adaptation, Mitigation and Geo-engineering 10.Ethics of Climate Change 11.Sustainable Development 12.The Global Challenge

3. Global Warming Global Warming is the increase in the average temperature of the Earth’s near surface air and oceans since the mid-20 th century and its projected continuation. (Wikipedia) 0.76°C (1.4°F) since 1900 0.55°C (1.0°F) since 1979 Global Temperature Change ( o C) Annual Mean 5-year Mean

4. Global Mean Temperature

5. Trend 1901-2005 Trend 1979-2005 Linear trend of annual mean temperatures

6. If there were no greenhouse gases the Earth’s temperature would be about 0  F (not 59  F) Greenhouse effect is real; without it, the Earth would be uninhabitable. Feedbacks amplify the warming by greenhouse gases. The Greenhouse Effect The Greenhouse Effect (The Cause of Global Warming)

7. Center of Ocean-Land- Atmosphere studies

9. A Tale of Three Planets Mars: −63 o C Earth: 15 o C (59 o F) Venus: 464 o C Surface Temperature MARS Sun Distance = 1.56 AU F = 592 W/m 2 Albedo = 17% T sfc = 210 K EARTH Sun Distance = 1.00 AU F = 1367 W/m 2 Albedo = 30% T sfc = 288 K VENUS Sun Distance = 0.72 AU F = 2639 W/m 2 Albedo = 78% T sfc = 737 K

10. If there were no greenhouse gases the Earth’s temperature would be about 0  F (not 59  F) Greenhouse effect is real; without it, the Earth would be uninhabitable. Feedbacks amplify the warming by greenhouse gases. The Greenhouse Effect The Greenhouse Effect (The Cause of Global Warming)

11. 1

12. Let us look at the Observations.

13. Global Mean Temperature

14. Sea Level Rise over the Last Century thermal expansion added freshwater (melting)

15. (Himalayas)

17. Arctic Sea Ice is Disappearing 2007: 38% below average 2008: 34% below average

18. Arctic Sea Ice is Disappearing

19. Rising Temperature in Chesapeake Bay

20. Let us look at the Greenhouse Gases.

21. Warming 1. Greenhouse gases (CO 2, CH 4, N 2 O) CO 2 : Carbon Dioxide : Emission from fossil fuel CH 4 : Methane : Agriculture N 2 O: Nitrous Oxide 2. Land use change Cooling 1.Aerosols Man made/Natural Volcanoes ※ Rate of increase of GHG is largest in 10,000 years (Net) Global Warming

22. Evidence for Human-induced Changes in GHGs (Overwhelmingly convincing!) ※ Rate of increase of GHG is largest in 10,000 years

23. Monthly Mean Carbon Dioxide NOAA CMDL Carbon Cycle Greenhouse Gases Atmospheric carbon dioxide mixing ratios determined from the continuous monitoring programs at the 4 NOAA CMDL baseline observations. Principal investigator: Dr. Pieter Tans. NOAA CMDL Carbon Cycle Greenhouse Gases. Boulder, Colorado. (303) 497-6678

24. Degrees Celsius above or below 30-year average global temperature

25. An Elegant Science Question: Are increases in greenhouse gases responsible for increase in global mean temperature (global warming)? 395 365 335 305 275 14.6 14.4 14.0 13.8 13.4 14.2 13.6 Global Temperature & Carbon Dioxide 1860-2008

26. Greenhouse gases increase due to human activities. Global warming is due to increases in greenhouse gases. Global warming is due to human activities. Hypothesis Alternative Hypothesis Global warming is due to natural variations of climate. How do you test such hypotheses? Climate Models; IPCC

27. Equations of motions and laws of thermodynamics to predict rate of change of: T, P, V, q, etc. (A, O, L, CO 2, etc.) 10 Million Equations: 100,000 Points × 100 Levels × 10 Variables With Time Steps of: ~ 10 Minutes Use Supercomputers What is a Climate Model?

28. IPCC has been established by WMO and UNEP to assess scientific, technical and socio- economic information relevant for the understanding of climate change, its potential impacts and options for adaptation and mitigation. Intergovernmental Panel on Climate Change (IPCC) Working Group I: The Physical Science Basis Working Group II: Impacts, Adaptation and Vulnerability Working Group III: Mitigation of Climate Change Largest number of U.S. scientists: nominated by the U.S. Govt. Highest skepticism : “U.S. Govt.”

29. Projection of Global Warming Mean of 15 Models Surface Air Temperature Difference (Sresa1b YR 71-100) minus (20c3m 1969-98), Global Average = 2.61

30. IPCC 2007 1.0º C Increase in Surface Temperature Observations Predictions with Anthropogenic/Natural forcings Predictions with Natrual forcings

31. Observed & Projected Global Mean Warming

32. Global Mean Sea Level Relative to the 1980 to 1999 mean

33. Impacts

34. Mohamed Nasheed President of the Maldives WANTED: New Home for My Country

35. Number of Days Over 100ºF Increases in very high temperatures will have wide-ranging effects. Recent Past, 1961-1979 Higher Emissions Scenario, 2080- 2099 Lower Emissions Scenario, 2080- 2099

36. Global Warming in Virginia 3 o Celcius warmer Between 0% to 10% more precipitation Annual

37. Summary of Major Impacts Heat waves; Droughts; Forest fires Coastal area’s habitability (sea level) Health (cholera; malaria; dengue; lyme) Biodiversity: extinction of species Agriculture (uneven); Tropics (serious) Water (drying; snow melt; glacier melt)

38. 1. Ignoring climate change will damage economic growth. (The poorest countries and people will suffer earliest and most.) 2. The damage will be on a scale similar to those associated with the great wars and the economic depression. 3. It will be difficult or impossible to reverse changes. 4. The earlier effective action is taken, the less costly it will be. STERN REVIEW: The Economics of Climate Change

39. Damages from business-as-usual scenario would be at least 5% and up to 20% of Global GDP a year Costs of removing most of the climate risk are around 1% of GDP per year This is equivalent to paying on average 1% more for what we buy “We can grow and be green” Sir Nicholas Stern STERN REVIEW: Main threat to a sustainable Earth

40. What We Can Do Let us look at the emissions

41. Global CO 2 Emissions In 2005, global emissions were 27 billion tons of CO 2 Per capita, emission (27/6.7 billions) = 4 tons/per capita/yr US emissions = 20 tons/per capita/yr

42. What is 4 tons of CO 2 per year? Drive 10,000 miles per year with a car that gives 30 miles per gallon. Fly 10,000 miles per year. 300 KWH per month of electricity from coal fired plant. 600 KWH per month of electricity from natural gas fired plant. (my house: 580 KWH in Mar. 2008; 380 KWH in Mar. 2009)

43. Center of Ocean-Land- Atmosphere studies

44. “Polluter must pay” (We (US) are the biggest polluters but we also have the biggest guns.) Those who have contributed the least to global warming will suffer the most and the earliest. Poor countries would like to improve the quality of life of their people (consume more energy). Sustainable developement in a changing climate is challenged by population growth and exetreme poverty. Ethics of Global Warming

45. What We Can Do Immediate action on conservation and energy efficiencyImmediate action on conservation and energy efficiency Help elect enlightened leaders and policymakersHelp elect enlightened leaders and policymakers Educate the publicEducate the public Social, economic, scientific, technological researchSocial, economic, scientific, technological research Create new institutionsCreate new institutions International dialogues and negotiationsInternational dialogues and negotiations Tax; Cap and TradeTax; Cap and Trade (Individuals; Institutions; Governments)

46. Provide food (and good life) to 9 billion people. Reduce odds of catastrophic impacts. No magic bullet (push on all fronts). Must reduce demand of CO2 (put a price). Cost in GDP ‘small’ but how to distribute? US must lead. Roles of Govts, Industry, Civil society Challenges and Opportunities

47. Our Common Future

48. Sustainable Development “The balance of economic growth, social justice, and environmental health that meets the needs of present generation and enables future generations to meet their needs.” Our Common Future (1987) The Brundtland Report

49. World Population World Population from AD 1 to 2002 Source: Data from Maddison (2001), Calculated using data from Maddison (2002) World Income from 1500 to 2001 World Income per Capita from 1500 to 2001 Since 1750, population increased 10 times; Production per person also increased 10 times; Therefore, total world economic production increased 100 times. Therefore, the impact of human activity on life- sustaining system on earth increased enormously. Planet under Stress ‘Common Wealth’ by Jeffrey Sachs, 2008

50. Global Poverty ‘Common Wealth’ by Jeffrey Sachs, 2008 From 1820 to 1992

51. Global Well-Being (sustainability, security and the future of civilization) The Global Challenge Inequality and Extreme Poverty Human Population Growth Environmental Degradation

52. Yes Managing planet Earth…… A new phase in human history An enormous challenge…… Are we up to it? THANK YOU!

53. ANY QUESTIONS?