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Palmer m 20150707_1700_upmc_jussieu_-_room_201

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Palmer m 20150707_1700_upmc_jussieu_-_room_201

  1. 1. Earth's energy imbalance (EEI): current knowledge and future challenges Dr. Matt Palmer
  2. 2. EEI must be central to our thinking around climate change:
  3. 3. EEI must be central to our thinking around climate change: • Most fundamental and robust measure of the rate of global change
  4. 4. EEI must be central to our thinking around climate change: • Most fundamental and robust measure of the rate of global change • Key to projections of future sea level rise (the time history of forcing matters)
  5. 5. EEI must be central to our thinking around climate change: • Most fundamental and robust measure of the rate of global change • Key to projections of future sea level rise (the time history of forcing matters) • Observations of EEI must be sustained and extended to the deep ocean
  6. 6. For a stable climate: incoming energy = reflected energy + emitted energy
  7. 7. Greenhouse gases reduce emitted energy
  8. 8. Global warming is the result of excess solar energy accumulating in the Earth System
  9. 9. Global warming is the result of excess solar energy accumulating in the Earth System The RATE of global warming is defined by EEI
  10. 10. von Schuckmann et al [submitted]
  11. 11. von Schuckmann et al [submitted] Ocean heat content (OHC) accounts for > 90% of EEI
  12. 12. von Schuckmann et al [submitted]
  13. 13. von Schuckmann et al [submitted] The symptoms of Earth’s energy imbalance
  14. 14. Credit: John Kennedy
  15. 15. Credit: John Kennedy
  16. 16. Credit: John Kennedy
  17. 17. Krakatoa SantaMaría Agung ElChichón Pinatubo Credit: John Kennedy
  18. 18. Palmer and McNeall [2014]
  19. 19. Palmer and McNeall [2014] Temperature is a poor indicator of EEI over a decade
  20. 20. Palmer and McNeall [2014]
  21. 21. OHC change is a reliable indicator of EEI over a decade Palmer and McNeall [2014]
  22. 22. Credit: Simon Good Observations of OHC: historical ocean profiles 0-700m
  23. 23. Observations of OHC: The Argo array of profiling floats
  24. 24. Observations of OHC: The Argo array of profiling floats Roemmich et al [2015]
  25. 25. von Schuckmann et al [submitted] Observations of OHC: The Argo array of profiling floats
  26. 26. Loeb et al [2012] Observations of EEI: Clouds and Earth’s Radiant Energy System (CERES, NASA) Net Energy
  27. 27. Outgoing long-wave energy Reflected short-wave energy Credit: NASA Observations of EEI: Clouds and Earth’s Radiant Energy System (CERES, NASA)
  28. 28. What about the future..?
  29. 29. Surface temperature rise under climate change
  30. 30. Ocean heat content (OHC) rise under climate change
  31. 31. EEI and OHC must be central to our thinking around climate change: • Most fundamental and robust measure of the rate of global change • Key to projections of future sea level rise (the time history of forcing matters) • Observations of EEI must be sustained and extended to the deep ocean (for OHC)
  32. 32. Questions..? Thanks to: Dan Bernie, Simon Good, Jonathan Gregory, John Kennedy Chris Roberts, Kevin Trenberth, Karina von Schuckmann
  33. 33. Additional slides..
  34. 34. How do Argo floats work?
  35. 35. Church et al [2011] OHC change accounts for 30-40% global sea level rise
  36. 36. Church et al [2011] IPCC AR5 [Church et al, 2013] OHC change accounts for 30-40% global sea level rise
  37. 37. IPCC AR5 Summary for Policy Makers Symptoms of Earth’s energy imbalance..
  38. 38. IPCC AR5 Summary for Policy Makers Symptoms of Earth’s energy imbalance..
  39. 39. IPCC AR5 [Myhre et al, 2013] Radiative forcings give rise to Earth’ energy imbalance
  40. 40. Observations AND climate models tell us we must measure the deep ocean in order to reliably track EEI and global sea level rise Purkey and Johnson [2010]
  41. 41. Key points #1: 1. Earth’s energy imbalance (EEI) is the most fundamental aspect of climate change science (and should be central to our thinking around this topic) 2. The various aspects of observing climate change are *symptoms* of the EEI 3. On multi-decadal timescales surface temperature rise (most used metric of global change?) responds to climate (radiative) forcings 4. However, on decadal timescales there is little or no correspondence between EEI and trends in surface temperature. Thus, much of the discussion around the “hiatus” may be missing the point (?) 5. This is because the ocean is a dynamic fluid, and can re-arrange heat. Total ocean heat content constitute > 90% of planetary heating associated with EEI
  42. 42. Key points #2: 6. Highlight two critical (and highly complementary) advances in Earth system observations: (i) CERES netTOA measurements; (ii) Argo observations of OHC 7. Briefly describe the strengths and weaknesses of each: (i) excellent coverage and information on radiative components, but unknown absolute value; (ii) high absolute accuracy but large sampling “noise” and under-sampled regions (ice covered, shallow seas, deep ocean) 8. EEI and OHC behave very differently to surface temperature under future climate scenarios. Show RCP4.5 and RCP8.5. for surface temperature and global thermal expansion (sea level). 9. MUST consider EEI and it’s evolution in our thinking communication around climate change. Importance of maintaining CERES, Argo and extending the Ocean Observing system.

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