1 / 50

1. Review

CLIM 101: Weather, Climate and Global Society. 1. Review. Jagadish Shukla. Lecture 25: Dec 1, 2009. The Greenhouse Effect (The Cause of Global Warming). If there were no greenhouse gases the Earth’s temperature would be about 0 F (not 59F)

millermartha
Télécharger la présentation

1. Review

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. CLIM 101: Weather, Climate and Global Society 1. Review Jagadish Shukla Lecture 25: Dec 1, 2009

  2. The Greenhouse Effect(The Cause of Global Warming) • 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.

  3. An Elegant Science Question: Are increases in greenhouse gases responsible for increase in global mean temperature (global warming)? 14.6 Global Temperature & Carbon Dioxide 1860-2008 395 0.76°C (1.4°F) since 1900 14.4 365 0.55°C (1.0°F) since 1979 14.2 335 14.0 13.8 305 13.6 275 13.4

  4. A Puzzle Greenhouse effect and global warming are determined by laws of physics, yet the opinions of the American public are divided along political and ideological lines: Conservatives, Republicans, Some corporations: “Fearmongering Hoax” Liberals, Democrats, Environmentalists: “Real and Present Danger”

  5. Global Mean Temperature

  6. Global Warming is Real and Unequivocal • Rising Temperatures (land, ocean) • More Hot Days; Less Frost Days • Melting Glaciers and Arctic Sea Ice • Decreasing Winter Snow Cover • Rising sea level • Poleward and Northward Shift of Species

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

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

  9. Observed & Projected Global Mean Warming

  10. 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)

  11. Impacts

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

  13. STERN REVIEW: The Economics of Climate Change • 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.

  14. STERN REVIEW: Main threat to a sustainable Earth • 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

  15. Global CO2 Emissions • In 2005, global emissions were 27 billion tons of CO2 • Per capita, emission (27/6.7 billions) • = 4 tons/per capita/yr • US emissions = 20 tons/per capita/yr

  16. What is 4 tons of CO2 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)

  17. CLIM 101: Weather, Climate and Global Society 2. What You Can Do Jagadish Shukla Lecture 25: Dec 1, 2009

  18. Reading for Lecture 25What You Can Do • RG Part 5 • GW Chapter 12

  19. Two Recent Books

  20. Adaptation & Mitigation • Adaptation: initiatives and measures to reduce the vulnerability of natural and human systems against actual or expected climate change effects • Mitigation: actions to reduce greenhouse gas emissions and to enhance sinks aimed at reducing the extent of climate change

  21. Adaptation, Mitigation, and Sustainable Development 1. Adaptation can reduce vulnerability to climate change. 2. Adaptive capacity is uneven across society and is connected to social and economic development 3. Substantial adaptation and mitigation can be achieved with existing technology.

  22. Examples of Mitigation Programs • Efficient vehicles; Reduced use of vehicles • Biomass fuel to replace use of oil • Efficient buildings; Efficient appliances • Replace coal power plants with natural gas, nuclear, solar • Add wind turbines for power generation • Capture and store carbon from power plants • Switch to Vegetarian diet • Stop deforestation; replant forests

  23. Stabilization Activities • CO2 Capture and Storage • Forests and Soils • Nuclear Fission • Fuel Switch • Energy Efficiency/Conservation • Renewable Electricity/Fuels

  24. Mitigation • Conservation • Alternative Energy (solar, wind, biofuels, etc) • Carbon Capture and Sequestration • Geoengineering

  25. Geo-engineering • Ultrafine sulfur particles injected into the upper atmosphere could reflect -2% of incoming solar radiation (enough to cancel global warming this century?) (Volcanoes cool the planet; in 1991 Mount Pinatubo in the Philippines cooled the planet for 1-2 years by ~0.5°C) • Increase the reflectivity of marine stratocumulus clouds by spraying a fine mist of sea water into the air; reflect back solar radiation and cool the planet!! (1500 ships (~2 million per ship)can increase reflectivity by 10% enough to counteract warming). • White roof tops reflect 75% and black rooftops reflect 5% of incoming solar radiation; metal roofs 60% (Temperature of rooftop: Black, 180ºF; Metal, 160°F; White, 120°F.

  26. Mitigation Geoengineering • Inject sulfur particles into the upper atmosphere  reflect solar radiation (Volcanoes) • Spray sea water  increase reflectivity of marine stratus clouds  reflect solar radiation (1500 ships ~ increase reflectivity by 10%) • White roof tops

  27. Geoengineering • Reducing the amount of carbon in the atmosphere • To convert CO2 as solid form 2. Reduce amount of sunlight reaching Earth • Inject sulfur particles into the upper atmosphere  reflect solar radiation (Volcanoes) • Spray sea water  increase reflectivity of marine stratus clouds  reflect solar radiation (1500 ships ~ increase reflectivity by 10%) • White roof tops

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

  29. Greenhouse Gas Emission Targets IPCC: 25% below the 1990 level by 2020 IPCC: 80% below the 1990 level by 2050 New York: 10% below the 1990 level by 2020 Vermont: 25% below the 1990 level by 2012 Virginia: 0% below the 2000 level by 2025 Waxman-Markey:17% below the 2005 level by 2020

  30. House vs. Senate Bill

  31. Examples of Adaptation in Agriculture Agriculture is strongly influenced by the availability of water. Climate change will modify rainfall, evaporation, runoff, and soil moisture storage, both seasonal mean and variability. Adaptive practices to the changes in water availability for agriculture include: • Distribution networks • Drought tolerant crop varieties • More spending on irrigation • Rainwater storage • Weather control • Cloud seeding • Replicating the urban heat island effect to increase rain downwind • Damming glacial lakes • Protects communities at risk of sudden glacial dam bursts • Provides hydroelectric power

  32. Agricultural Practices • Mulching, no-till farming, use of cover crop and use of manure for 1.5 billion hectares worldwide could sequester about one billion tons of carbon dioxide each year.

  33. Inter-relationships Between Adaptation and Mitigation • Effective climate policy aimed at reducing the risks of climate change to natural and human systems involves a portfolio of diverse adaptation and mitigation actions • Decisions on adaptation and mitigation are taken at different governance levels and inter-relationships exist within and across each of these levels • Creating synergies between adaptation and mitigation can increase the cost-effectiveness of actions and make them more attractive to stakeholders, including potential funding agencies • It is not yet possible to answer the question as to whether or not investment in adaptation would buy time for mitigation • People’s capacities to adapt and mitigate are driven by similar sets of factors

  34. Electricity Consumption/person in the US and California (current electricity generation in the US ~ 1 TW, 2020 ~ 1.4 TW) U.S. California Thanks: R. Cicerone

  35. Recent US Trends: Encouraging • 9% drop in US emissions in past 2 years • (Recession; High gasoline price; Efficiency; Non-carbon energy) • Wind farms, Solar power plants rapidly increasing • Corporations concerned about risk, public opinion • EPA ready to regulate Carbon under the Clean Air Act • (Supreme court, 2007); ”A glorious mess”

  36. Our Common Future

  37. The last 10,000 years have been ideal for the development of human societies: This has been a unique time during which climate varied very little and thereby enabling human-kind to flourish IPCC 2007 Number of Years before the Present (quasi-log scale)

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

  39. Challenges and Opportunities • 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

  40. 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

  41. Managing planet Earth…… A new phase in human history An enormous challenge…… Are we up to it?

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

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

  44. Spiritual Dimension of Climate Change • “God gave man stewardship over the Earth, and that preserving it for future generations is a sacred obligation” – Al Sharpton & Pat Robertson an odd couple, plea for “taking care of the planet.” • Gore: gives training to Christian , Muslim, Hindu, Jewish groups.

  45. Think Globally, Act Locally Adaptation measures need to take a local / regional focus

  46. Class on Thursday (3 Dec) • Location: Robinson Hall, B113 • Time: 10:30 AM

  47. Center of Ocean-Land-Atmosphere studies THANK YOU! ANY QUESTIONS?

More Related