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Climate Change Science: What we know today and future impacts

Climate Change Science: What we know today and future impacts

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Climate Change Science: What we know today and future impacts

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  1. Climate Change Science: What we know today and future impacts Dr. Roberta Johnson University Corporation for Atmospheric Research Education and Outreach

  2. Overview • Why climate change science in the classroom? • Climate versus Weather • Climate Models • Climate Change Observations • IPCC 4th Assessment Summary for Policy Makers • Future Impacts Annual layers of ice, Quelccaya Ice Cap, Peru Courtesy of Lonnie Thompson

  3. Why Focus on Climate Change? • Societal Relevance • National Science Education Standards (NRC, 1996) • Interdisciplinary content spans broad spectrum of the geosciences • Opportunities for authentic inquiry-based learning • A focus area providing opportunity for students to engage in research-driven learning with high motivation in an interdisciplinary context. Polar bears on melting ice berg in Beaufort Sea, 2004 Courtesy Environment Canada

  4. Relevance of Climate Change to the NSES • Unifying concepts and processes • Science as Inquiry • Physical Science • Life Science • Earth and Space Science • Science and Technology • Science in Personal and Social Perspectives • History and Nature of Science

  5. NSES Content Standards, Grades 5-8

  6. NSES Content Standards, Grades 9-12

  7. We’re all familiar with the Weather The state of the atmosphere at a given time that includes temperature, precipitation, humidity, pressure, winds.

  8. Climate • Global climate is driven by energy from the Sun and modulated by atmospheric composition

  9. The average weather for a region over a long period of time – 30 years or more • Determined by latitude, altitude, topography, proximity to oceans/position in land mass • Characterized by temperature, winds, and rainfall

  10. You buy clothes based on climate You wear clothes based on weather

  11. The Challenge of Simulating the Global Earth System Hydrosphere Cryosphere Biosphere Atmosphere

  12. Timeline of Climate Model Development

  13. Model Resolutions R15 T42 T170 T85

  14. Climate System Models

  15. Global mean surface temperatures have increased

  16. Increase in temperature tracks carbon emissions and CO2 ~ highest level of CO2 over past 400 Kyrs

  17. A Warming World… NASA

  18. 450,000 yrs ago time today CO2, CH4 and temperature records from Antarctic ice core data Source:Vimeu et al., 2002, 100’s of thousands of years:Ice Core Data

  19. Glaciers are Retreating Globally In Switzerland… In Alaska…

  20. Qori Kalis Glacier, Quelccaya Ice Cap, Peru between 1978 and 2000. Courtesy of L. Thompson, Byrd Polar Research Center

  21. 10-15% Decrease in Arctic Sea Ice Revealed by NOAA Operational Satellites

  22. Permafrost in the Arctic is melting, leading to infrastructure damage as well as disrupting subsistence life styles

  23. Ice is breaking up earlier on rivers and lakes in the spring around the world

  24. Rise in Global Mean Sea Level

  25. 250 Year Record of Leafing Out Date of English Oaks

  26. Intergovernmental Panel on Climate Change (IPCC)

  27. IPCC 2007Summary for Policymakers Greenhouse gas concentrations have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values. • CO2 increase from fossil fuel and land-use changes • Methane, nitrous oxide due to agriculture IPCC 4th Assessment Summary for Policy Makers, 2007

  28. IPCC 2007Summary for Policymakers Warming of the climate system is unequivocal, evident from observations of • Increases in global average air and ocean temperature • Widespread melting of snow and ice • Rising global mean sea level IPCC 4th Assessment Summary for Policy Makers, 2007

  29. IPCC 4th Assessment Summary for Policy Makers, 2007

  30. IPCC 2007 Summary for Policymakers Warmth of the last half century is unusual in at least the previous 1300 years. The last time polar regions were significantly warmer than present for an extended period (about 125,000 years ago), reductions in polar ice volume led to 4-6 meters of sea level rise.

  31. Natural Variations do not explain observed climatic change • Climate models with natural forcing (including volcanic and solar) do not reproduce warming • When increase in greenhouse gases is included, models do reproduce warming • Addition of increase in aerosols (cooling) improves agreement

  32. IPCC 4th Assessment Summary for Policy Makers, 2007

  33. IPCC 2007 Summary for Policymakers For the next 2 decades a warming of .2C/decade is projected. Even if greenhouse gas/aerosol concentrations had been constant at yr 2000, further warming of .1C/decade would result due to slow response of the ocean. Continued greenhouse gas emissions at or above current rates will cause further warming and induce many changes in global climate system this century larger than those observed in the last century.

  34. IPCC 4th Assessment Summary for Policy Makers, 2007

  35. IPCC 4th Assessment Summary for Policy Makers, 2007

  36. IPCC Emission Scenarios • A1- rapid economic growth, population growth peaks and declines mid 2100s, rapid introduction of new, more efficient technologies. Convergence among regions, capacity building, cultural/social interactions, reduction in regional differences in per capita income. • A1B – balance across all sources • A1FI – Fossil-fuel intensive energy solutions • A1T – non fossil-fuel energy solutions • A2 – heterogeneous world, self reliance, slow reduction in population growth, economic development primarily regional, fragmented and slow growth in per capita income and tech growth • B1 – convergent world, population peak mid 2100s and declines (like A1), rapid change to service/information economy, reductions in material intensive, introduction of clean, resource efficient technology, global solutions, improve equity, but without addl climate initiatives • B2 – local solutions to economic, social, and environmental sustainability problems. Continuously increasing global population, at rate lower than A2, intermediate economic development, less rapid and more diverse tech change than in A1 and B1. No scenarios include climate initiatives, meaning that none assume that UN Framework Convention on Climate Change or emissions targets of Kyoto Protocol are enacted

  37. IPCC 2007 Summary for Policymakers Higher confidence in projected patterns of warming and regional-scale features, continuing currently observed trends: • warming greatest over land and at most high northern latitudes (least over Southern Ocean and parts of NA ocean) • snow cover will contract • widespread increases in thaw depth over most permafrost regions • sea ice will shrink in both Arctic and Antarctic, in some projections late summer sea ice disappears in the Arctic by latter part of 21st century • very likely that hot extremes, heat waves, and heavy precipitation events will continue to become more frequent • likely that typhoons and hurricanes will become more intense • extra-tropical storm tracks will move poleward • precipitation at high latitude very likely to increase, while decreases are likely in most subtropical land regions • Very likely that meridional overturning circulation of the Atlantic Ocean will slow down during the 21st century. Average reduction by 2100 is 25% (0-50%). Very abrupt transition is very unlikely in 21st century. Anthropogenic warming and sea level rise will continue for centuries due to the timescales associated with climate processes and feedbacks, even if greenhouse gas concentrations were stabilized

  38. Under the Scenario A2…Business-As-Usual This is What Happens to Arctic Sea Ice

  39. Past and Future Rise in Sea Level 20,000 years ago 2200? ( + 5 meters)

  40. Multiple new dynamic mechanisms for increased ice sheet sensitivity to surface warming have been discovered Zwally et al., (2002) Science Alley et al. (2005) Science