Johnston, Stephen T.

English

University of New Brunswick: Centre for Digital Scholarship Journals

GEOSCIENCE CANADA Volume 38  Number 4 December 2011 147PRESIDENTIAL ADDRESSThe Earth Sciences: OurLegacy and our FutureStephen T. JohnstonSchool of  Earth and Ocean ScienceUniversity of  VictoriaPO Box 3065, STN CSCVictoria, BC, Canada, V8W 3V6E-mail: stj@uvic.caINTRODUCTIONThe motto of  the 2011 Ottawa AnnualGeneral meeting of  the Geological andMineralogical associations of  Canada,“Navigating Past & Future Change”,was intended to highlight our commit-ment, as a scientific community, to theexploration of  both the science andsocietal significance of  the Earth Sci-ences. What I intend to do in this Pres-idential Address is to turn the mottoaround and restate it as a question:What is the scientific and societal sig-nificance of  the Earth Sciences? Thisis not an idle question. Many of  thoseattending the Ottawa GAC–MACmeeting are dependent upon a govern-ment paycheque, either because wework in universities or for governmentlabs and surveys. In addition, much ofour research is funded by governmentgrants, most notably through theNSERC Discovery grants program. Inother words, our jobs and our researchare dependent upon public recognitionof  our contribution to society. So what is the scientific andsocietal significance of  the Earth Sci-ences? To answer that question I wantto go back to a remarkable time in ourhistory, the late 1700s, and in particularto three key developments of  thattime. Those developments were noth-ing less than 1) Hutton’s discovery ofdeep time; 2) Smith’s invention of  themodern geological map; and 3) therealization that humans are a compo-nent of  the Earth system. These threeintellectual leaps all occurred at theexact moment that atmospheric CO2concentrations started their inexorableand ongoing rise. As the scientistsmost responsible for finding the coal,oil, gas and mineral resources on whichmodern society is built, we can take agreat deal of  pride in the role thatgeology and the Earth Sciences haveplayed in civilization’s evolution overthe past two hundred and fiftyyears. The prosperity of  modern soci-ety is rooted in the discovery of  deeptime and the invention of  the geologi-cal map: that is our legacy. It is, how-ever, in addressing and understandingour role in the Earth system that ourfuture scientific and societal signifi-cance is to be found.HUTTON AND THE DISCOVERY OFDEEP TIMEThe year is 1788. Three Scottish gen-tlemen clambered into a ‘wee’ boat andheaded down the east coast of  Scot-land. These three were the physicianand experimental farmer James Hut-ton, the mathematician John Playfairand the naturalist James Hall. Theymade a precarious landing at SiccarPoint, where Hutton was able, for thefirst time, to convincingly demonstratehis discovery of  deep time. Anyonewho has ever tried to read Huttonknows that had he not managedto enlist Playfair as an advocate, appre-ciation of  the significance of  his dis-covery may have been very muchdelayed, for Hutton was not an elo-quent writer. Playfair was. And so,despite the familiarity of Playfair’sdescription of  that momentous day atSiccar Point, it is so beautifully writtenthat it bears repeating:“We felt ourselves necessarily carriedback to the time when the schistus on whichwe stood was yet at the bottom of  the sea, andwhen the sandstone before us was only begin-ning to be deposited, in the shape of  sand ormud, from the waters of  a superincumbentocean. An epoch still more remote presenteditself, when even the most ancient ofthese rocks, instead of  standing upright invertical beds lay in horizontal planes at thebottom of  the sea and was not yet disturbedby that immeasurable force which hasburst asunder the solid pavement of  the globe.Revolutions still more remote appeared in thedistance of  this extraordinary perspective. Themind seemed to grow giddy by looking so farinto the abyss of  time; and while we listenedwith earnestness and admiration to thephilosopher who was now unfolding to us theorder and series of  these wonderful events, webecame sensible how much farther reasonmay sometimes go than imagination can ven-ture to follow.”I am struck by a couple ofprescient aspects of  Playfair’s render-ing of  that day on Siccar Point. Thefirst is his reference to deformation ofthe crust as being attributable to an“immeasurable force which has burst asunderthe solid pavement of  the globe.” In thosefew words Playfair came as close toplate tectonics as anyone would foranother 150 years. The second isfound in Playfair’s description of  howhe and Hall sat listening “with earnestnessand admiration” as Hutton explained thesignificance of  the rocks beforethem. I could not help but think thatthese words still adequately describegeological field trips: while none of  uswill ever participate in such a signifi-cant field trip, we all have benefittedfrom the earnest and admirable effortsof  field trip leaders.Deep Time! Without DeepTime and the intimately linked conceptof uniformitarianism, there could beno Charles Darwin and no evolution.148Without Deep Time there could be nounderstanding of  the immensity of  theuniverse as we know it, for Deep Timeis a requirement of  light having trav-elled interstellar distances. And ofcourse there would be no plate tecton-ics without first understanding theDeep Time available for the movementof  plates. So unfathomable is DeepTime, so far removed is Deep Timefrom human experience, that none ofus can fully grasp its scale. That Hut-ton, Playfair and Hall realized even afraction of  the implications of  theirdiscovery is a staggering, amazingachievement.WILLIAM SMITH AND INVENTIONOF THE MODERN GEOLOGICAL MAPThe second major act of  the late 1700swas played out near Bath in southwest-ern England. William Smith, who madehis living building canals to transportcoal, drew up his first geological mapshowing the geology of  the Bathregion. It was one of  the first maps bywhich it was recognized that theEarth’s crust consisted of  a sequenceof  layers that always occurred in thesame order. He also realized that fos-sils were unique to each layer, and thatthere was an evolution in certain typesof  fossils from one layer to the next.And it was based on that map thatWilliam Smith later constructed cross-sections in which he was able to reveal,indeed to predict, not only the struc-ture of  the Earth at depth, but also toshow the crust that had already beenremoved by erosion; the cross-sectionsshowed that once continuous layersof rock had been eroded away andgreat masses of  rock removed.As anyone who has everattempted to make a geological mapwill know, it is a beast. It is neitherpure data, nor an outright model. Ageological map is the productof observational (not experimental)science, but any and all attempts tomap in a purely observational fashionare doomed to produce the lousiest ofmaps. If  you do not believe me, Iinvite you to come teach field schoolwith me sometime.William Smith was, by 1815,able to publish a geological map ofmost of  Great Britain. He did notmanage this by visiting every outcrop.What he did was develop amodel!! Smith’s model was nothingmore than the recognition that thecrust underlying Great Britain wascharacterized by a set stratigraphicsequence that had subsequently beenfolded and faulted. Using his model,together with the sparse data availablefrom outcrop and canal-cuts, he thenproduced a predictive map that he wassubsequently able to test against therocks exposed in each new canal. Thiswas the leap. This was the inventionof  the modern geological map. Smith’sgeological map of  Britain is, like allgood geological maps, a mixture ofobservation and model. It is neither‘stamp collecting’, to use a phrase oftemployed to describe observational sci-ences, nor is it the product of  repeat-able experimentation. There is nothingquite like the geological map in anyother science. The map is what distin-guishes us, and William Smith’s map ofGreat Britain, which proved to beremarkably accurate, is justifiably rec-ognized as a great scientific achieve-ment.HUMANITY AS A GEOLOGICALAGENTFinally, I turn to the third major devel-opment of  the late 1700s: the realiza-tion that man was an active componentof  the Earth system. We need to firststep back to 1763, the year that JamesWatt invented his ‘efficient’ vacuumsteam engine. Watt had a workingengine by 1765, and in 1776, the yearof  the American Revolution, the Wattsteam engine was made widely avail-able. This was the golden age of theIndustrial Revolution, complete withthe urbanization of Great Britain, andthe first development of  large-scalecoal mining – coal that was used togenerate the steam required byWatt’s engines. You can imagine thechange in the landscape: there was thewidespread development of  high-den-sity urban areas that proliferated acrossformerly pastoral landscapes; therewere the coal mines, the canals (con-structed by William Smith) needed todeliver the coal, and the pollutionstemming from burning of  the coal. Itwas, in 18th century Great Britain,impossible not to realize thathumans were reshaping the face of  theEarth.It was Robbie Burns who per-haps best captured that realization withhis poem ‘To a Mouse’ (see inset boxpage 150). The poem, published in1786, a scant two years before Hutton,Hall and Playfair visited Siccar Point, isironic: in the face of  the onrushingindustrialization, Burns turned his eyeinstead to the seemingly benign prac-tice of  pastoral farming, farming as ithad been practiced for centuries. Andwhat Burns cleverly showed was thateven farming comes at a cost. Implicitin the poem is the question ‘if  farmingcomes at a cost to the Earth, whatthen is the cost of  industrialization?’The poem is a eulogy to amouse whose nest is turned upby Burns as he ploughs his fields.There is much debate over whetherBurns ever laid his hands upona plough as he is now commonly por-trayed as an almost mythical layabout,womanizer and drinker (no wonder heis so revered). Regardless, what Burnsdoes is to use the mouse and its nest asan analog for the natural world; it is anintricate system that is part of, and hasevolved in response to the Earth’s sys-tem. And then along comes man,embodied in Burns’ plough (the ‘cruelcoulter’), and in a geological instant,everything is changed. Burns speaksdirectly to industrialization in the sec-ond stanza:I’m truly sorry man’s dominionHas broken Nature’s social unionBut Burns also sees thequandary:I backward cast my e’eOn prospects drear!An’ forward, tho’ I canna see,I guess an’ fear!Burns recognizes that you can-not go back to the poverty (prospectsdrear) that characterized too many livesbefore industrialization. But he alsolooks upon the changes wrought byindustrialization and though he cannottell the future, he fears it. He fears itbecause, unlike farming, whose costwas known and understood, the costof  industrialization was unknown. Andhe fears it because, to return to themost famous line of  the poem, “the bestlaid plans o’ mice and men, gang aft agley.”OUR FUTUREThere is now broad and growing con-cern that the best laid plans mayindeed have gone awry. We are nowGEOSCIENCE CANADA Volume 38  Number 4 December 2011 149incomparably rich compared to eventhe richest 1% of  all people living inthe late 1700s. And geologists have hada great deal to do with ourenrichment. The recognition of  deeptime has provided the backdrop for avast array of  scientific advances, frombiological engineering to nuclearphysics. Geological maps have beeninstrumental in the finding andexploitation of  the coal, gas, oil andminerals that form the foundation onwhich our prosperity, health andlongevity has been built. But as with18th century pastoral farming, prosperi-ty is not without a cost, and the ‘cost’is CO2, the main byproduct of  indus-trialization (Figure 1).It may be ironic that the dis-covery of  deep time, the invention ofthe geological map, and the realizationthat man is a geological agent ofchange, all lie together right at the startof  the modern rise in the concentra-tion of  atmospheric CO2. It may beironic, but it surely is no coinci-dence. And so we are, like Friedrich’s‘Wanderer Above a Sea of  Fog’ (Figure2), left with little in the way of  choiceregarding where we go from here. Wecannot descend back into the fog ofignorance, nor the poverty of‘prospects drear’ that preceded indus-trialization. And as huge as the role ofthe Earth Sciences has been in bring-ing about the health and prosperity weenjoy today, our future scientific andsocietal contribution is going to haveto be equally significant, if  not moreso.What is the challenge beforeus? We need to understand the roleplayed by humans in bringing aboutthe ongoing changes in the Earth sys-tem, and we need to know the magni-tude and scope of  the changes facingus over the next 250 years. To do thiswe must understand how Earth hasworked in the past. Geological mapsand our understanding of  deep timeare our legacy, but they are also thetools that we must use to remain soci-etally and scientifically relevant. Rocksare a repository of  information on theprocesses responsible for changes inthe biosphere, hydrosphere, atmos-phere and solid Earth. And we cannoteven begin a conversation regardingthe significance of  increasing atmos-pheric concentrations of  CO2, far lesswhat to do about it, if  saddled with awoefully incomplete understanding ofhow the Earth system has respondedto changes of  this nature and magni-tude in the past.I give the last word to JohnPlayfair who, when faced with the con-cept of  Deep Time, said so well “webecame sensible how much farther reason maysometimes go, than imagination can venture tofollow.” The message to take fromPlayfair’s words is this: it is not goodenough for us, as Earth Scientists, tocome to a conference, give a scientifictalk and then return to our offices, lab-oratories and field areas to continueour research. That is only half  of  ourwork. The only way that society isgoing to support us is if  they too canreason. We have to educate thepublic. Outreach cannot be the sparetime pursuit of  the minority of  Earthscientists. Outreach has to be centralto our science, for a public ignorant ofthe basic workings of  the Earth and ofthe depth of  Earth history, will neverbe able to imagine the substantial chal-lenge that humanity currently faces.Figure 1.  CO2 vs. time.  (Note: the ‘air age’ is younger than the age of  the icefrom which the air was extracted due to continued interchange with the atmos-phere for a limited time after snow deposition and its subsequent conversion to ice.The CO2 mixing ratio is the number of  molecules of  CO2 relative to the totalnumber of  molecules per unit volume of  the air extracted from the ice, and isreported as ppm by standard convention). Modified from Etheridge et al. (1998). Figure 2.  Friedrich’s ‘WandererAbove a Sea of  Fog’.150REFERENCEEtheridge, D.M., Steele, L.P., Langenfelds,R.L., Francey, R.J., Barnola, J.-M., andMorgan, V.I., 1998, Historical CO2records from the Law Dome DE08,DE08-2, and DSS ice cores, In Trends:A Compendium of  Data on GlobalChange: Carbon Dioxide InformationAnalysis Center, Oak Ridge NationalLaboratory, U.S. Department of  Ener-gy, Oak Ridge, Tenn., USA.To a MouseRobert BurnsWee, sleekit, cow’rin’, tim’rous beastie,O what a panic’s in thy breastie !Thou need na start awa sae hasty,Wi’ bickering brattle !I wad be laith to rin an’ chase theeWi’ murd’ring pattle ! I’m truly sorry man’s dominionHas broken Nature’s social union,An’ justifies that ill opinionWhich makes thee startleAt me, thy poor earth-born companion,An’ fellow-mortal ! I doubt na, whiles, but thou may thieve;What then? poor beastie, thou maun live !A daimen-icker in a thrave‘S a sma’ request:I’ll get a blessin’ wi’ the lave,And never miss’t ! Thy wee bit housie, too, in ruin !Its silly wa’s the win’s are strewin;And naething, now, to big a new ane,O’ foggage green !An’ bleak December’s winds ensuin’Baith snell an keen ! Thou saw the fields laid bare an wasteAn’ weary winter comin’ fast,An’ cozie here, beneath the blast,Thou thought to dwellTill, crash! the cruel coulter pastOut thro’ thy cell. That wee bit heap o’leaves an’ stibbleHas cost thee mony a weary nibble !Now thou’s turn’d out, for a’ thy trouble,But house or hald,To thole the winter’s sleety dribbleAn’ cranreuch cauld ! But, Mousie, thou art no thy laneIn proving foresight may be vain:The best laid schemes o’ mice an’ menGang aft a-gley,An lea’e us nought but grief  an’ pain,For promised joy.Still thou are blest, compared wi’ me !The present only toucheth thee;But, Och ! I backward cast my e’eOn prospects drear !An’ forward, tho’ I canna see,I guess an’ fear !

The Earth Sciences: Our Legacy and our Future

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The Earth Sciences: Our Legacy and our Future

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