Northern Exposure 2: 1 March Whither the Ice and Cold? Danny Blair. dannyblair.uwinnipeg.ca

Transcription

1 Northern Exposure 2: 1 March 2013 Whither the Ice and Cold? Danny Blair dannyblair.uwinnipeg.ca Associate Dean of Science, University of Winnipeg Principal, Richardson College for the Environment (Acting) Professor of Geography Co-Chair, MB s Climate Change climateguy@gmail.com

2 Summary: Duh, global warming continues (hasn t stopped) No, it is not a natural cycle It will continue for decades +

3 Summary: The climate, including ours, is on track for major changes (esp. in the North) Expect more extremes, and surprises, in the future

4 Summary: Long-range planning is money and time well spent We must not give up on mitigation

5 Global Climate is Warming NASA: 2010 was tied for warmest year on record 2011 was 9 th warmest 2012 was ~tied for 9 th Anomalies relative to

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7 2011/12: 3 rd Warmest Winter ( )

8 2012: 9 th Warmest Spring ( )

9 March 2012 Difference from Normal

10 Winnipeg March Mean Temperatures

11 2012: Warmest Summer ( )

12 2012: 17 th Warmest Autumn ( )

13 2012: Warmest Year on Record for U.S. Canada: 3 rd Warmest ( )?

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15 Many people around the world now realize that their climates are no longer normal.

16 But why so much variation in the global temperature trend?

17 Major volcanic eruptions cool the planet for a few years Through Jan El Niño warms the planet for ~2 yrs; La Niña cools for ~2 yrs

18 Niño evolution since La Niña El Niño neutral La Niña 25 Feb 13

19 Record Warmth In Recent Years Even though solar irradiance was very low ~11-year (132-month) sunspot cycle Carbon dioxide forcing is about 1.5 W/m 2 and growing (~0.3 W/m 2 per decade) Data through Jan

20 Global Land-Ocean Temperature Index Red: smooths out El Niño/La Niña Blue: smooths out solar cycle Through Dec

21 Why is the global temperature rising?

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23 The Keeling Curve ppm Data through Dec

24 Concentrations of Greenhouse Gases, Year 0 to Year 2005 Carbon dioxide now 394 ppm IPCC 2007

25 Glacial-Interglacial Ice Core Data We have excellent estimates of ancient carbon dioxide concentrations from bubbles extracted from ice cores.

26 How do we know what the temperature was 800,000 years ago?

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29 Ice cores stored in the National Ice Core Lab in Colorado. Photograph by: Peter Rejcek National Science Foundation Date Taken: March 15,

30 Hydrogen (1 proton + 1 electron) Add a neutron proton (+) electron (-) Warm air has more heavy hydrogen Now it is much heavier hydrogen deuterium 2 H or D

31 Oxygen (8 protons + 8 electrons) Add 2 neutrons % of oxygen is this isotope It is still oxygen just heavier 17 O is much rarer N = 8 protons + 10 neutrons = 18 O

32 Some water molecules are heavier than others 16 O Oxygen 17 O 18 O Warm air has more heavy oxygen 1 H 2 H Hydrogen 1 H Hydrogen 2 H

33 When the atmosphere is cold: Precipitation is depleted in heavy 18 O or 2 H Winter/Cold precipitation is isotopically light

34 Glacial-Interglacial Ice Core Data We have excellent estimates of ancient global temperatures thanks to isotopes extracted from ice cores.

35 Why so much interest in carbon dioxide?

36 The Earth s Energy Balance and the Greenhouse Effect IPCC 2007

37 Radiative Forcing: The change in the net, downward minus upward, irradiance at the top of the tropopause due to a change in an external driver of climate change (expressed in Watts per square metre; W/m 2 ). More greenhouse gases = more radiative forcing = more energy for warming IPCC 2007

38 Carbon dioxide is responsible for ~64% of the total radiative forcing of Earth by long-lived greenhouse gases. Its contribution to the increase in radiative forcing is 85% for the past decade and 81% for the last five years.

39 Radiative forcing between 1750 and 2005 Total Net Forcing from Humans 1.6 W/m 2 IPCC 2007

40 Observation: Earth surface = 510 million million m Watts per m 2 equals: 816 million million Watts 816 terawatts (TW) Total worldwide energy consumption rate: ~16 TW

41 Of interest: Radiative forcing decreasing by several W/m 2 resulted in glaciers covering almost all of Canada.

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43 Ice Sheets Grow Milankovic Cycles Greenhouse Effect Weakens More Sunlight Reflected Colder Forests Die Colder Oceans Deep Ocean Stores More CO 2 Less Water Vapour in Air Less CO 2 in Air Greenhouse Effect Weakens Less CO 2 in Air Tundra Replaces Forests Carbon Gets Locked in Permafrost Windier Dust Fertilizes Oceans Algae Bloom Shells Grow Ocean Can Hold More CO 2 Carbon in Shells Sink to Bottom

44 Conclusion from our understanding of how climates changed in the past and current changes: Humans now control the global climate. James Hansen and grandchildren James Hansen:

45 IPCC CO 2 CONCENTRATION SCENARIOS A1F1 A2 A1B B2 B1 Currently ~394 ppm Socio-economic and geophysical models are used to make projections about future carbon dioxide (and GHG) concentrations.

46 RCP = Representative Concentration Pathway

47 Alas: There are few signs that we are going to substantially slow down our carbon emissions any time soon.?

48 Alas: There is no quick fix. It is very unlikely that we will be able to prevent substantial warming.

49 Decay of Fossil Fuel CO 2 Emission 33% of CO 2 remains in air after 100 years 19% remains in air after 1000 years

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51 Equilibrium Climate Sensitivity Surface warming following a sustained doubling of CO2 concentrations Best estimate 3 C likely C and very unlikely less than 1.5 C higher values IPCC 2007

52 Important: Warming triggers many other climate changes, because of feedback processes.

53 Greenhouse Effect Stronger Sea Ice Shrinks Less Sunlight Reflected Warmer Warmer Oceans More Water Vapour in Air Deep Ocean Absorbs Less CO 2 More CO 2 in Air Greenhouse Effect Stronger Permafrost Thaws Forests Die Back More CO 2 and Methane in Air CO 2 and Methane Released

54 Warming leads to more evaporation More evaporation increase intensity and duration of drought Clausius Clapeyron equation Warmer air also holds more water vapour (7% more per +1 C) More water vapour will create more precipitation (with favourable weather patterns) More atmospheric moisture provides more latent heat for storms

55 Conclusion: The entire climate system changes as well, not just the temperature. There are many signs that the system is changing.

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57 Released March

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61 Many people around the world now realize that their climates are no longer normal.

62 2000 England and Wales Wettest autumn on record since Germany Highest daily rain since at least Europe Hottest summer in at least 500 years 2007 Greece Hottest summer on record since Australia Heatwave breaks many long records 2010 Russia Hottest summer since Pakistan Worst flooding in history 2010 E. Australia Highest December rainfall since France Record hot/dry spring since N.E. USA Wettest Jan-Oct on record since S. USA Most extreme Jul. heat/dry since W. Europe Wettest summer on record since Japan 72-hour rainfall record 2011 Rep. of Korea Wettest summer on record since Canada Souris-Assiniboine River Floods

63 Extremes 2012 Arctic Lowest sea ice cover on record 2012 Antarctic Highest sea ice cover on record 2012 Canada Record high temps in March 2012 Canada/U.S. Record winter drought in many areas 2012 United States Hottest year on record in lower United States Hottest summer on record in lower Canada Hottest summer on record 2012 Europe Many areas record hottest summer 2012 United States Drought breaks many long records 2012 Russia, Ukraine + Drought raises food prices 10% 2012 United States Hurricane Sandy kills ~200; ~$70B 2012 Greenland 97% of surface was melting in July 2012 Eurasia Extreme cold spell in Jan/Feb 2012 S. Philippines Rare Super Typhoon kills 100s in Dec 2012 NE Brazil Extreme drought worst in 5 decades 2012 Africa Floods in Jul-Oct affects >3 million 2013 Australia Record heat wave in January 2013 Australia Record high temp in Sydney in Jan Canada Record highs in Yukon, Edm. In Jan.

64 Climate normals are dead: The averages are changing rapidly The climate is becoming more variable The past is no longer a good surrogate for the future

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66 What changes in temperature and precipitation are projected for our region?

67 Update coming soon Canada s most recent assessment of climate change impacts and adaptation, region by region.

68 Prairie Grassland Region: 2050s Spring Wetter & Warmer

69 Climate Trend Mapper Free! at climate.uwinnipeg.ca

70 Spring Avg. Temperature Trend

71 Prairie Grassland Region: 2050s Summer Drier? & Warmer

72 Summer Avg. Temperature Trend

73 Prairie Grassland Region: 2050s Fall Wetter? & Warmer

74 Fall Avg. Temperature Trend

75 Prairie Grassland Region: 2050s Winter Wetter & Warmer

76 Winter Avg. Temperature Trend

77 Annual Avg. Temperature Trend

78 Use average of 16 of the latest climate models to estimate changes in PRECIPITATION and changes in the DIFFERENCE BETWEEN PRECIPITATION AND EVAPOTRANSPIRATION. Comparing to Use the RCP8.5 emissions scenario.

79 Change in PRECIPITATION: Fall Months

80 Change in PRECIPITATION: Winter Months

81 Change in PRECIPITATION: Spring Months

82 Change in PRECIPITATION: Summer Months

83 Change in PRECIP-ET: Fall Months

84 Change in PRECIP-ET: Winter Months

85 Change in PRECIP-ET: Spring Months

86 Planning is important: Forecasting extreme events is very difficult The most important events are the extremes

87 IPCC 2001

88 Number of Days with Temperature Exceeding 30 C

89 Overall, the evidence indicates a likely increase in observed heavy precipitation in many regions in North America, despite statistically non-significant trends and some decreases in some sub-regions. This general increase in heavy precipitation accompanies a general increase in total precipitation in most areas of the [country]. The largest trends toward increased annual total precipitation, number of rainy days, and intense precipitation.were focused on the Great Plains/northwestern Midwest. Chapter 3

90 There will be benefits: Longer growing season More heat for growing More crop/garden choices Improved yields Longer warm-fun season Warmer winters

91 There will be many risks: More extreme heat events More cooling requirements More severe storms More winter rain hazards More weeds and pests More social stress Shorter cold-fun season

92 There will be many risks: More frequent droughts More intense droughts Longer droughts More extreme rain events A more variable climate More climate surprises

93 Science: 1 Feb 2008 Stationarity the idea that natural systems fluctuate within an unchanging envelope of variability is a foundational concept that permeates training and practice in water-resource engineering. It implies that any variable (e.g., annual streamflow or annual flood peak) has a timeinvariant (or 1-year periodic) probability density function (pdf), whose properties can be estimated from the instrument record.

94 Of Concern: The amount of nonstationarity that will be present in the future is unknown Also unknown: what we do not know

95 Donald Rumsfeld: "We know there are known knowns: there are things we know we know. We also know there are known unknowns: that is to say we know there are things we know we don't know. But there are also unknown unknowns the ones we don't know we don't know." 12 February 2002

96 Social and Climatological Tipping Points? A winter with no snow? A mega-drought or flood? A global food crisis? A methane outburst? A sudden global warming? Must we rely upon catastrophism?

97 Northern Exposure 2: 1 March 2013 Whither the Ice and Cold? climateguy@gmail.com

98 Bonus Material:

99 What caused greenhouse gas concentrations to rise and fall in the past?

100 IPCC

101 Orbital eccentricity (~100,000 yrs)

102 Axial tilt (obliquity) (~41,000 yrs)

103 Axial precession (~26,000 yrs)

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105 Climate Projections for Southern Manitoba: Executive Summary Annual Mean Temperature Winter Mean Temperature Spring Mean Temperature Summer Mean Temperature Fall Mean Temperature Variable Projected Change Confidence +1 to +3 C by 2050 Very High +3 to +5 C by 2050 Very High +1 to +2 C by 2050 Very High +1 to +2 C by 2050 Very High +1 to +2 C by 2050 Very High Maximum Temperatures Warming slower than means Very High Minimum Temperatures Warming faster than means Very High These are summaries of the overall projected trends as reported in From Impacts to Adaptation: Canada in a Changing Climate 2007 (2008); The New Normal: The Canadian Prairies in a Changing Climate (2010); IPCC s Climate Change 2007: The Physical Science Basis (2007); and other select sources compiled by D. Blair.

106 Climate Projections for Southern Manitoba: Executive Summary Variable Projected Change Confidence Warm-season heat waves Warmer and more frequent Very High Heat extremes Warmer and more frequent Very High Cooling-degree days Much higher Very High Heating-degree days Much lower Very High Growing-degree days Much higher Very High Frost-free season Much longer Very High Mid-winter thaws Warmer and more frequent Very High Winter-cold snaps Shorter and less frequent Very high Snow cover season Much shorter Very high Length of winter season Much shorter Very high Winter freeze-thaw cycles More frequent Low Cold nights Warmer and fewer Very high These are summaries of the overall projected trends as reported in From Impacts to Adaptation: Canada in a Changing Climate 2007 (2008); The New Normal: The Canadian Prairies in a Changing Climate (2010); IPCC s Climate Change 2007: The Physical Science Basis (2007); and other select sources compiled by D. Blair.

107 Climate Projections for Southern Manitoba: Executive Summary Variable Projected Change Confidence Annual precipitation Modest increase Medium Winter precipitation Substantial increase Very High Spring precipitation Increase Medium Summer precipitation Lower Low Fall precipitation Increase Low Winter rain events Many more Very high Snow storms Fewer Medium Droughts More and longer High Intense rain events More and more intense High Days with rain/snow? Low Days without rain/snow? Low Surface water amount Less Medium These are summaries of the overall projected trends as reported in From Impacts to Adaptation: Canada in a Changing Climate 2007 (2008); The New Normal: The Canadian Prairies in a Changing Climate (2010); IPCC s Climate Change 2007: The Physical Science Basis (2007); and other select sources compiled by D. Blair.

108 Climate Projections for Southern Manitoba: Executive Summary Variable Projected Change Confidence Wind speed? Low Wind extremes Higher Medium Wind erosion Higher Low Cloud cover? Low Sunshine? Low Relative humidity? Low Summer severe weather More Medium Lightning More Medium Tornadoes More Medium Surface water temperature Higher Very high Carbon dioxide Higher Very high These are summaries of the overall projected trends as reported in From Impacts to Adaptation: Canada in a Changing Climate 2007 (2008); The New Normal: The Canadian Prairies in a Changing Climate (2010); IPCC s Climate Change 2007: The Physical Science Basis (2007); and other select sources compiled by D. Blair.

109 Climate Projections for Southern Manitoba: Executive Summary Variable Projected Change Confidence Year to year variability Higher High Climate extremes Higher High Spring flooding More frequent Low Local summer flooding More frequent High Very wet summers More frequent Low Very dry summers More frequent Medium Very hot summers More frequent High Very wet winters More frequent High Very cold winters Much less frequent Very high Positive impacts Some, decreasing with time Very high Negative impacts Many, increasing with time Very high These are summaries of the overall projected trends as reported in From Impacts to Adaptation: Canada in a Changing Climate 2007 (2008); The New Normal: The Canadian Prairies in a Changing Climate (2010); IPCC s Climate Change 2007: The Physical Science Basis (2007); and other select sources compiled by D. Blair.