Climate Change: The Physical BasisThe Fellowship- March 1st 2014 Alan Journet Ph.D.Professor emeritus (Biology/ Environmental Science) Southeast Missouri State University firstname.lastname@example.org Cell: 541-301-4107http://kaconjour.com Co-facilitatorSouthern Oregon Climate Action Nowhttp://socan.info Presentation http://socan.info/presentation-project/
Outline • Introductory remarks • Global patterns • Science and change • Competing hypotheses • Milankovitch • Solar activity • Galactic Rays • Volcanoes • Oscillations • Greenhouse Gases • Models and projections
What are these? 30 years teaching biology at Southeast Missouri State University: Mainly ecology, science methods, conservation biology – so let’s start with a little biology…... What incited my concern about climate change? As a Graduate Student Iwas a skeptic….
What Determines BiologicalCommunity Distribution? • Average Temperature. • Average Precipitation. X
So What? MAJOR BIOLOGICAL COMMUNITIES OF THE WORLD Not only do these represent whereour flora and fauna live…but These control the agricultural and forestry potential of our land
POTENTIAL FUTURE (TO 2100) OF CURRENT NATURAL COMMUNITES Business as usual CO2 850 ppm Some redress: CO2 550 ppm Within 500km Blue Probability = 1; Red Probability = -1 Williams & Jackson 2007: http://www.frontiersinecology.org/paleoecology/williams.pdf
CRITICAL VALUES “What have futuregenerations ever donefor me?” Intergenerational Justice Stewardship Newer carbon-free technologiescannot compete with freewaste allowance Externalizing waste allowspollution of our air – 97% of Climate Scientists agree – The planet is warming Free? Level Economic Playing Field Human caused gas emissions are contributing We all pay the price.
Should we manage our resources such that we meet the needs of the present without compromising the ability of future generations to meet their needs? or should we sacrifice the future environment for politics and short term economic profit? “Sustainable Economic Development” ‘Agenda 21’
Risk Assessment….A Personal Example 100 Prob. Of Survival 50 IV 40 III II 30 1995AML: Notreatment 20 I 10 12 NOW 2 24 TIME IN MONTHS A Medical Issue:Diagnosis and Response My Choices: 1 – Accept the diagnosis Conclude I have cancer, and undergo treatment. But they could be wrong…maybe I don’t have cancer. 2- Deny the diagnosis Conclude I’m fine, and decline treatment. But I could be wrong…maybe I do have cancer. What is the Prudent Response? Partisan??
Global Temperatures 1880 – 2013cf 1951-1980 Since early 1970s - 1.3⁰F Since 1880s - app. 2.0⁰F Since 1750s - >2.0⁰F 1998 1.08 .72 ⁰F .36 0 .36 .72 http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A.gif
Last 1,000 Years Only if we ignorerecent data can weargue it’s now nowarmer than the MWP Medieval Warm period 950 - 1250 LittleIce Age Continental-scale temperature variability during the past two millennia; 2013 Kaufmann et al. Nature Geoscience 6: 339 – 346 2013
Science, Proof, & Certainty • Science seeks explanations for phenomena evident in the world / universe around us, but • Proof (i.e. certainty) does not exist in science • Science operates by testing competing hypotheses, • Confidence in an idea grows only as - competing hypotheses are falsified / excluded, and • evidence accumulates in support of that hypothesis which remains unfalsified…. • By looking at past climate fluctuations and their causes we can explore competing hypotheses….
Is a changing climate unusual? 20,000 - 18,000 Over the last2 millions years4 glaciations have occurred 170,000 - 120,000 480,000 - 230,000 800,000 - 600,000
More Distant Historical Patterns in Temperature It has been hotter – but not for 2 million years Note: axis is not arithmetic http://www.chatham.edu/pti/Pgh_Env_History/Real01.htm Yes, it’s been hotter on the planet, but how relevant to us is > 2 million YA?
What Might Have Caused Historic Climate Changes? These are the competing Hypotheses 1 –The Milankovitch Cycle 2 – Solar Radiation Patterns – reasonable since 99.998% of Earth’s Energy comes from the sun 3 – Volcanoes emitting multiple materials 4 – ENSO / PDO /AMO regional oscillations 5 – The Current Greenhouse Gas Understanding 1 – Milankovitch
MilankovitchCycle A 100,000 year temperature cycle results from 3 component cycles: • I: 105,000 yr. cycle in shape of Earth’s orbitof sun-Eccentricity http://deschutes.gso.uri.edu/~rutherfo/milankovitch.gif
MilankovitchCycle • II: 41,000 yr. cycle in the tilt (obliquity of ecliptic) of Earth 21.1o-24.5o around 23.5o. http://deschutes.gso.uri.edu/~rutherfo/milankovitch.gif
MilankovitchCycle • III: 21,000 cyclic advance [Precession] of the equinoxes – date when sun is over equator…. Jan Feb March….. January. http://deschutes.gso.uri.edu/~rutherfo/milankovitch.gif
MilankovitchCycle • http://www.globalchange.umich.edu/globalchange1/current/lectures/samson/climate_patterns/ Consequence: • Inconsequential change in total solar radiation – but • A cycle in severity of seasons • From warm summers/cold winters to cool summers/mild winters • Glaciation occurs when summer is not warm enough to melt winter snows.
Coincidence in the three Milankovitch cycles WIS ILL • When all the Milankovitch cycles (alone) are taken into account, the present trend should be towards a cooler climate in the Northern Hemisphere, with extended glaciation. Warming Cooling Warming Cooling Warming Cooling Berger & Loutre 1991 – Available: http://academic.emporia.edu/aberjame/student/howard2/theory.htm
Solar Activity http://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm
400 Years of Sun Spot Activity The more sunspots, the greater the solar radiation Running Mean Little Ice Age 1550 – 18401 – 2°C colder caused famines Few sunspots http://en.wikipedia.org/wiki/Global_warming
http://en.wikipedia.org/wiki/Image:Carbon14_with_activity_labels.svghttp://en.wikipedia.org/wiki/Image:Carbon14_with_activity_labels.svg It certainly seems likely that solar patterns have influenced global climate recently…. Sun Spots Further Back In Time Medieval Warm Period
Total Solar Irradiance since 1600(NOTE: there has been a rise – but not recently) 3/1365 = 0.22% Note: App 11 yr cycle http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf
Curiously, the recent solar lull, longer and deeper than usual, is now ending: 0.1% Note: solar irradiance recently was lower than previously detected…. http://www.nasa.gov/pdf/719139main_2012_GISTEMP_summary.pdf
Galactic Cosmic Ray Influence http://news.bbc.co.uk/2/hi/uk_news/6290228.stm
Main Outputs • Water Vapor – positive climate impact • Carbon dioxide – positive climate impact • Ash – negative climate impact • Sulfur gases – aerosols negative impact But…. • Water vapor is short-lived in atmosphere • Land and sea volcanoes annually emit 200 million tons of CO2 • Human activity annually emits 24 billion tons of CO2 • Volcanoes < 1% human activity
Regional Climatic Oscillations • El Niño Southern Oscillation ENSO • Pacific Decadal Oscillation PDO • Atlantic Multi-decadal Oscillation AMO
El Niño events alternate with La Niña El Niño La Niña 1950 1960 1970 1980 1990 2000 2010 http://ggweather.com/enso/oni.htm
Pacific Decadal Oscillation Typical wintertime Sea Surface Temperature (colors) Sea Level Pressure (contours) and surface windstress (arrows) Anomaly patterns during warm and cool phases of the PDO http://jisao.washington.edu/pdo/ Cause unknown: events persist for 10 – 40 years, Primarily affect North Pacific / North America
Comparing PDO and Global Patterns http://www.skepticalscience.com/is-pacific-decadal-oscillation-the-smoking-gun.html
Atlantic Multi-decadal Oscillation http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-3-33.html
My interpretation of the evidence regarding the competing hypotheses for current climatic variation? • Astronomic Patterns: the Milankovitch Cycle • Fluctuations in Solar / Cosmic Radiation • Volcanic Activity • ENSO, PDO & AMO • Variation in Atmospheric Greenhouse Gases
The Greenhouse Gas Explanation IT ALL STARTS WITH INCOMING SOLAR RADIATION High energyshortwavelengths Visible mediumwavelengths Heat longwavelengths MicrowavesTV/Radio FM-AM
Hot bodies emit radiation in shorter wavelength form = Visible and UV Light Energy Cooler bodies emit radiation in longer wavelength form = Heat Energy What Happens to Incoming Radiation? Heat wavelengths TRANSFORMATION
The Planetary Greenhouse Effect
The Atmospheric “GreenhouseEffect" Transformed toInfra-red = heat. Then what? Remainder escapesinto space some re-radiated out Some infra-red is absorbed by atmospheric gases Incoming Visible light WARNING: Not drawn to scale
Some infra-red is absorbed by atmospheric gases NOTE: Absorbency is in lower atmosphere – which is where we live
Less escapesinto space If atmospheric gas density increases, more heat is retained by this ‘thermalblanket’ Warming Surface - LowerAtmosphere
As more heat is retained, less escapes into space Atmospheric Layers? Warming Warming Cooling What proportion of this Heat Energy is absorbed by our atmosphere (as opposed to going elsewhere)? Surface - LowerAtmosphere Troposhere to app. 14 km. 14km Stratosphere 50 km
Components of a Heating Planet http://www.skepticalscience.com/graphics.php?g=12
Current average global temp is app 15oC or 59oF Without this thermal blanket Earth would be 200Cto 300C (350F – 550F) cooler, probably too cold to support life – certainly as we know it. Warming Warming Cooling Surface - LowerAtmosphere Troposhere to app. 14 km. 14km Stratosphere 50 km
There’s nothing new under the sun…. 1824 Joseph Fourier: Visible radiation earth’s surface infra-red radiation trapped in atmosphere (thermal blanket) 1861 John Tyndall: Identified heat trapping gases: water vapor, carbon dioxide So, what are these ‘greenhouse gases?’ - • 1896 Svante Arrhenius: industrial revolution inc. carbon dioxide temp effects • Arrhenius did NOT win a Nobel Prize….for this - Not a new or novel idea 1930s/1940s E.O. Hulburt; Gary Stewart Callendar 1960 Charles David Keeling: Monitored carbon dioxide, published first ‘Keeling’ curve. 1970 George Benton PNAS 1980s James Hansen of NASA GISS
The Main Greenhouse GasesGWP = Global Warming Potential Carbon dioxide Methane 100 year GWP = 1 100 year GWP = 25 CFC / HCFC Longevity ≈ centuries Longevity ≈ decade 100 year GWP = 15,000 Longevity ≈ 250 years Nitrous oxide Longevity ≈ 10 Days 100 year GWP = 298 Water Dihydrogen monoxide Longevity ≈ century
Positive and Negative AtmosphericRadiative Forcing Components Level ofScientificUnderstanding CO2 CH4 N2O Reflectance High coolingLow warming Dust and Droplets Aviationcontrails slight + IPCC AR4 Synthesis Report; Fig 2-4
Keeling Curve with annual pattern Now 400 ppm Inc. by76 ppmsince 1958/60 =24% 316ppm http://en.wikipedia.org/wiki/Keeling_Curve
Now 400 ppm Since 1750? The Keeling Curve Not been this high since Pliocene 3.2 – 5 m YA Inc. by 120 ppmsince 1750 = 43% 1750 http://www.oism.org/pproject/s33p36.htm
The CO2 / Temp Pattern http://www.globalchange.umich.edu/globalchange1/current/lectures/samson/climate_patterns/
400,000 years of CO2 and last 1000 yearsIce Core and Modern Data http://en.wikipedia.org/wiki/Global_warming http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf