Sec on 3-4: Radia on, Energy, Climate

Transcription

1 Sec on 3-4: Radia on, Energy, Climate Part 2 Learning outcomes list and describe the major natural and anthropogenic forcings of recent CC understand the effect of feedbacks on amplifying or dampening CC understand important aspects of the climate system relevant to CC GEOG 313/513 Fall 2014 Global Climate Change 1 Prof J. Hicke

2 Sec on 3-4: Radia on, Energy, Climate Part 2 Outline Forcings introduc on and defini ons natural forcings anthropogenic forcings feedbacks Other key climate concepts GEOG 313/513 Fall 2014 Global Climate Change 2 Prof J. Hicke

3 Sec on 3-4: Radia on, Energy, Climate Part 2 Outline Forcings introduc on and defini ons natural forcings anthropogenic forcings feedbacks Other key climate concepts GEOG 313/513 Fall 2014 Global Climate Change 3 Prof J. Hicke

4 Sec on 3-4: Radia on, Energy, Climate introduc on and defini ons Forcing: defini on: a factor causing change; driver; effect Radia ve forcing: defini on: change in net irradiance at tropopause due to a change in an external driver of climate change in units of W/m 2 currently 2.4 W/m 2 Global Climate Change 4 Prof J. Hicke

5 Sec on 3-4: Radia on, Energy, Climate Part 2 Outline Forcings introduc on and defini ons natural forcings anthropogenic forcings feedbacks Other key climate concepts GEOG 313/513 Fall 2014 Global Climate Change 5 Prof J. Hicke

6 Sec on 3-4: Radia on, Energy, Climate Natural forcings 1. solar ac vity (solar radia on) a. sunspots 11- year cycle affect solar radia on by 0.1% Global Climate Change 6 Prof J. Hicke

7 en.wikipedia.org/wiki/solar_cycle Global Climate Change 7 Prof J. Hicke

8 Kitchen, Pearson Education, Inc. Global Climate Change 8 Prof J. Hicke

9 Lately, solar ac vity decreasing while warming calscience.com/graphics.php?g=5 Global Climate Change 9 Prof J. Hicke

10 Sec on 3-4: Radia on, Energy, Climate Natural forcings 1. solar ac vity (solar radia on) 2. orbital changes Milankovitch cycles important in last 2 million years consist of three components Global Climate Change 10 Prof J. Hicke

11 Obliquity Kitchen, Pearson Education, Inc. Global Climate Change 11 Prof J. Hicke

12 Eccentricity Kitchen, Pearson Education, Inc. Global Climate Change 12 Prof J. Hicke

13 Precession combines with eccentricity Key for climate: which hemisphere (N or S) points toward the sun at perihelion oceanworld.tamu.edu Global Climate Change 13 Prof J. Hicke

14 Keys for influencing Earth s climate Orbital changes 1. Northern Hemisphere has more land mass than Southern Hemisphere land supports ice sheets NH has cooler summers (allowing ice sheet growth) when Earth s lt is minimal orbit is most eccentric lt: NW away from sun at perihelion 2. small orbital changes ini ate large climate changes 3. orbital dynamics are well described and predictable cooling for last 6000 years, expected cooling for next 100,000 years (from orbital changes alone) Global Climate Change 14 Prof J. Hicke

15 Orbital, solar forcing Kitchen, Pearson Education, Inc. Global Climate Change 15 Prof J. Hicke

16 Sec on 3-4: Radia on, Energy, Climate Natural forcings 1. solar ac vity (solar radia on) 2. orbital changes 3. volcanoes periodic erup ons material into stratosphere reflec on of SW radia on - > cooling of Earth s surface Global Climate Change 16 Prof J. Hicke

17 Mt. Pinatubo, 1991 diveshoppe2003.wordpress.com Kitchen, Pearson Education, Inc. Global Climate Change 17 Prof J. Hicke

18 Mt. Pinatubo, 1991 diveshoppe2003.wordpress.com anima on: h p://svs.gsfc.nasa.gov/stories/aura_prelaunch_ / images/item2_mpeg_1_web_big.mpeg Global Climate Change 18 Prof J. Hicke

19 Mt. Pinatubo, 1991 Kitchen, Pearson Education, Inc. Global Climate Change 19 Prof J. Hicke

20 Kitchen, Pearson Education, Inc. Global Climate Change 20 Prof J. Hicke

21 Sec on 3-4: Radia on, Energy, Climate Natural forcings 1. solar ac vity (solar radia on) 2. orbital changes 3. volcanoes 4. natural variability Global Climate Change 21 Prof J. Hicke

22 Natural Climate Variability climate system oscillates between states ( modes ) modes have mul year to mul decadal periods currently not well understood (- > limited capacity for predic on) many different modes ENSO: El Nino/Southern Oscilla on (also, La Nina) PDO: Pacific Decadal Oscilla on AMO: Atlan c Mul decadal Oscilla on AO, PNA, current understanding: affect, but not responsible for, current warming Global Climate Change 22 Prof J. Hicke

23 El Niño/Southern Oscilla on Kitchen, Pearson Education, Inc. Global Climate Change 23 Prof J. Hicke

24 El Niño/Southern Oscilla on iri.columbia.edu Global Climate Change 24 Prof J. Hicke

25 ENSO effects on global climate cool phase (= La Niña) warm phase (= El Niño) Kitchen, Pearson Education, Inc. Global Climate Change 25 Prof J. Hicke

26 ENSO effects on global warming Foster and Rahmstorf, 2012 Global Climate Change 26 Prof J. Hicke

27 Atlan c Mul decadal Oscilla on and effects on hurricanes Kitchen, Pearson Education, Inc. Global Climate Change 27 Prof J. Hicke

28 Pacific Decadal Oscilla on Global Climate Change jisao.washington.edu/pdo 28 Prof J. Hicke

29 PDO s effects on US Northwest Temperature green = T, black (red, blue) is PDO appinsys.com/globalwarming/pdo.htm Global Climate Change 29 Prof J. Hicke

30 Sec on 3-4: Radia on, Energy, Climate Part 2 Outline Forcings introduc on and defini ons natural forcings anthropogenic forcings feedbacks Other key climate concepts GEOG 313/513 Fall 2014 Global Climate Change 30 Prof J. Hicke

31 Greenhouse gases 1. Water vapor water vapor: the most important GHG (greatest GH effect) most abundant GHG (up to 3% of atmospheric mass) 36-70% of greenhouse effect (=surface warming rela ve to a planet with no atmosphere) short atmospheric life me (= rapid cycling of one water vapor molecule between ocean, atmosphere, land) ~days human ac vi es have minimal effect water vapor acts as a posi ve feedback to warming Global Climate Change 31 Prof J. Hicke

32 Greenhouse gases 1. Water vapor 2. Well- mixed GHG CO 2, CH 4, N 2 O, halocarbons Global Climate Change 32 Prof J. Hicke

33 Greenhouse gases 1. Water vapor 2. Well- mixed GHG 3. Ozone troposphere pollutant from human ac vi es stratosphere protector of life through UV radia on absorp on some CC impact through circula on changes Global Climate Change 33 Prof J. Hicke

34 Greenhouse gases Global warming poten al assess, compare impact of GHG other than CO 2 compares GH effect on a per mass basis considers loca on, width of spectral band of absorp on atmospheric life me o en reported in CO 2 - equivalent (CO 2 e) Global Climate Change 34 Prof J. Hicke

35 Global Climate Change 35 Prof J. Hicke

36 Global Climate Change 36 Prof J. Hicke

37 note that me increases from right to le! Global Climate Change 37 Prof J. Hicke

38 Anima on of CO2 h p:// history.html Global Climate Change 38 Prof J. Hicke

39 Small varia ons in CO 2 in space, me Kitchen, Pearson Education, Inc. Global Climate Change 39 Prof J. Hicke

40 Trends in GHGs Kitchen, Pearson Education, Inc. Global Climate Change 40 Prof J. Hicke

41 Including all greenhouse gases in calcula on of CO 2 e Global Climate Change 41 Prof J. Hicke

42 Anthropogenic land cover change as climate forcing conversion from forest to grassland, cropland leads to increases in albedo biogeophysical effect separate from biogeochemical effect of CO2 increase locally important, minimal global effect Global Climate Change 42 Prof J. Hicke

43 Contribu on of land use change to radia ve forcing via albedo changes IPCC AR5 WG I, 2013 Global Climate Change 43 Prof J. Hicke

44 Aerosols Defini on: ny liquid and solid par cles suspended in the atmosphere cause haze, smog both natural and anthropogenic in origin en.wikipedia.org Global Climate Change 44 Prof J. Hicke

45 Aerosol plume Kitchen, Pearson Education, Inc. Global Climate Change 45 Prof J. Hicke

46 Aerosols Types important for climate Sulfate aerosols reflect shortwave radia on - > cooling sources natural: volcanoes, biology (plankton) anthropogenic: fossil fuel burning, fires Black carbon absorb shortwave radia on - > warming sources natural: fires anthropogenic: fossil fuel burning, fires Global Climate Change 46 Prof J. Hicke

47 Aerosols Direct effect radia ve forcing is on shortwave radia on, not longwave Heating Sulfate aerosols Bright Aerosols Black carbon and soot Dark Aerosols figure courtesy John Abatzoglou Global Climate Change 47 Prof J. Hicke

48 Global dimming and global warming Global Climate Change dimming- and- global- warming 48 Prof J. Hicke

49 Indirect effect on climate Aerosols provide condensa on nuclei for cloud forma on more clouds brighter clouds longer- lived clouds radia ve forcing: cooling earthobservatory.nasa.gov Global Climate Change 49 Prof J. Hicke

50 Comparison of GHG and aerosols Similari es: Both natural and anthropogenic in nature Both can alter climate Differences: Aerosols are short- lived in the atmosphere (10- days on average), whereas GHG are long- lived ( years) GHG act primarily on longwave radia on, aerosols primarily on shortwave radia on Scien sts are much more certain about the influence of GHG on climate than the influence of aerosols on climate Aerosols are regional in nature, GHG are global in nature Global Climate Change 50 Prof J. Hicke

51 Global Climate Change IPCC AR5 51 WG I, 2013 Prof J. Hicke

52 Contribu ons of major GHGs to warming Kitchen, Pearson Education, Inc. Global Climate Change 52 Prof J. Hicke

53 Contribu ons to radia ve forcing since 1750 Global Climate Change IPCC AR5 53 WG I, 2013 Prof J. Hicke

54 Sec on 3-4: Radia on, Energy, Climate Part 2 Outline Forcings introduc on and defini ons natural forcings anthropogenic forcings feedbacks Other key climate concepts next lecture GEOG 313/513 Fall 2014 Global Climate Change 54 Prof J. Hicke