cc  >> All right, now I'd like to  introduce our second speaker.  And thank you, very much,  John, for your presentation.  Our second speaker  is Jack Williams.  He's an associate professor in  the Department of Geography in  the Center for Climatic Research  at the University of Wisconsin  Madison.  He's currently the Bryson  Professor of the Climate, People  and Environment program, named  in honor of Reid Bryson, a  pioneer climatologist at  UW-Madison who's one of the  first to recognize the  vulnerability of human societies  and ecosystems to climate  change.  Jack studies the responses of  plant communities to climate  change and studies climate  changes from the past to better  understand the changes of the  future.  Jack received his PhD in 1999  from Brown University  and joined Madison in the fall  of 2004 after a postdoctoral  position at the National Center  for Ecological Analysis and  Synthesis and at the University  of Minnesota.  >> Thanks a lot Mike.  Okay, I'm just going to get  set up here for a second.  Okay, make sure I'm oriented  here. 

 Okay, hopefully you can see that  pointer there.  I'll be using that as my pointer  in this talk today.  I'm just getting over a cold so  excuse me.  I'd first like to say it was  both a great honor to follow  John Magnuson here and also a  great challenge.  It's a great talk and he's been  doing a lot of work and he's  been a pioneer in this field of  ecosystem impact and adaptations  of climate change for many years  now so it's great to be teamed  up for this presentation series.  I'd also like to thank Mike  Notaro, the Nelson Institute for  Environmental Studies, the  Department of Natural resources  at Wisconsin and Wisconsin  Public Television.  And thank you for coming.  Okay, I guess one confession  up front, the title, the series  promises a focus on Wisconsin  ecosystems and climate change  but I'm going to be going a  little bit more broadly here.  I'll be working on time scales  of the last hundred years to the  last actually 20,000 years or  so, and then I will be working  at a spatial scale that's more  regional to continental from the  United States to North America,  with Wisconsin in that context.  I'd like to start with the main  points of this talk first, the  main messages of this talk. 

 The first one being that we are  already seeing the ecological  consequences of climate change.  And I think John, in his talk,  outlined in the aquatic systems  some very nice examples of both  the physical systems, changes in  ice cover, and then changes in  biological systems as well.  Another point I'd like to make  in this talk is the idea that  many of our impacts and the  consequences of our recent  greenhouse gas emissions, the  temperature and other climatic  changes that result from those  greenhouse gas emissions are  still in the pipeline  ecologically.  And I'll go into the reasons for  that later in this talk.  And then zooming out to the last  20,000 years, which has been one  of the primary time scales that  I've worked on on my own  research, is showing this point  that even small temperature  change, on the order of a few  degrees Celsius or a few degrees  Fahrenheit, can have very large  ecological effects.  And just one little comment down  here at the bottom, this talk  will be 99% model free.  I'm really going to focus on  actual data and actual time  series as much as possible.  I know when talking with  students and reading online  commentary about various studies  there's a lot of skepticism out  there about the climate models  that are used and the ecological  models that are driven by these  climate models.  There's actually very good  reason to believe in the  robustness of these climate  models and the ecological models  that work from them, but that's  sort of a separate lecture onto  itself.  So here what I'm going to focus  on is actually time series, both  on relatively short scales and  longer time scales, documenting  ecological responses to recent  and not-so-recent climate  change. 

 Okay, so again this is a data  again here.  This is a record of changes in  temperature over the last  hundred years.  This is from the IPCC and the  2007 report here, and if you can  see at the right there it ends,  I believe the IPCC report ended  in 2001 and since then the  temperatures of the last several  years had leveled out but the  overall pattern is still there.  That we've had about a  three-quarters of degree warming  over the last hundred years.  And you see there's variability  in this.  Just as John was pointing out in  his talk there are years and  decades where there are  relatively high temperatures and  low temperatures but you can  draw a line from that trend, and  the long-term trend underlying  that year-to-year and  decade-to-decade variability is  about three-quarters  degrees Celsius  or 1.33 degrees Fahrenheit.  Even this relatively subtle  warming, which you might not  think is a very large amount of  warming, has been having  ecological, or we should be  careful here, is believed to  have ecological consequences.  There's a pretty straightforward  and it's not a big leap of faith  but we should note that there's  a hypothesized connection here.  But there are various biological  events that are timed to  temperature just like there are  these physical events, such as  the date of ice break, the date  of freeze, there are various  biological events that are  temperature cued by temperature  changes over the course of a  season.  The dates of animal migration,  the dates of leaf senescence in  the fall, the date of bud burst  and leaf-out in the spring. 

 For many organisms over and over  again there has been well showed  these are strongly temperature  cued ecological phenomenon.  There's a whole branch of  science known as phenology which  is the study of the seasonal  timing of these ecological  events and the controls of the  seasonal timing of these  ecological events.  And so the biological systems,  this is believed to be one of  the canaries in the coal mine  with respect to ecological  responses to temperature change.  Because it's a relatively quick  way for species to adjust  to changing temperatures.  It often takes a while for plant  populations to colonize new  areas or for change in the  abundance of various organisms,  some organisms or species die  out and others become more  abundant.  But regulating their cues in  response to these temperature  signals is a fairly fast way  that species can adapt to  climate change.  One of the things that we're  seeing in this bottom plot is  the fact that these various  signals, these springtime  signals, are occurring at  earlier and earlier dates.  And so what we're seeing there  on the left hand plot, this is a  whole variety of different, this  is a paper by -- looking at a  variety of different organisms  there.  So the change in the timing of  these events, that's the  vertical axis in days per  decade.  And you can see that most of the  bars in that plot there are  pointing down, meaning they are  occurring earlier in the spring  than they used to. 

 And you can see that range of  variability around that.  Some is occurring as many as 30  days earlier in the spring,  others actually occurring later  in the spring.  But if you take an average  across all these different  species, the many different  studies have compiled this data,  we can see there's an average  shift of about a two day earlier  onset of spring, when trees  start to bud out, when animals  start to migrate, and so forth.  There is just starting to be  evidence, and this is really in  the early stages of this, but  there is just starting to be  evidence now of actual shifts in  species ranges which is one of  the things that you would  predict from climate change.  That species have a climatic  niche that they can tolerate.  As John was talking about with  various fish species, they can  thrive and grow and reproduce  within that range of  temperatures but outside of it  their abundance has declined and  potentially go locally extinct  or extirpated.  One of the sets of species that  are again believed to be  relatively sensitive, another  one of these sort of early  indicators of ecological  responses to climate change, are  butterflies.  They are a temperature dependent  organism.  They are ectotherms.  They cannot regulate their own  body temperature. 

 They're dependent upon the  temperature of the environment  around them.  They can actually migrate.  They can move from spot to spot  relatively quickly in response  to climate change.  So this is just an example of  one study here from Spain where  there was a survey of butterfly  populations.  You can see the upper left map  shows the region of Spain that's  being zoomed in on here.  You can see there's two maps, at  right the one map from 1967-1973  a survey of butterfly  populations from this black  satyrs species shown at the  left.  And then the right one a  resurvey of those same species  roughly 30 years later in 2004.  The dots and circles are  probably a little hard to see  from where you are, and so the  key thing to look at is that  background color where you can  see the range, shown by the dark  shading, was relatively  extensive in the 1960s and 1970s  and that shrunk over the 30  years since then.  And this represents an up-slope  migration of this species, where  the lower elevation populations  of the species have died out.  And there's been some movement  of this population to higher  elevations, but the overall  effect is that there's been a  shrinkage of that species range,  because there's more area in the  low elevations, typically, than  the upper elevations. 

 So this up-slope range shift has  become an overall shrinking of  this species range.  Another area that is among  forest ecologists is causing  great concern, and this is where  it's critical to say we don't  fully know the exact cause of  this, we are working this out  still, but there is good reason  to suspect that climate is  implicated here, has been the  widespread tree mortality events  in the western Canada, the  western US.  This is a map from western  Canada here where the red shows  this amazingly large areas of  mountain pine beetle outbreaks  and then these mortality, these  die-offs of adult pines in these  areas.  And you may not be able to see  that figure in the lower right  down there but it shows a  mixture of green and red  patches.  Where the green are still living  trees, the red are dying or dead  trees.  And in this image there about a  third of the picture is now red  and it's sort of this patchy  distribution across the  landscape there.  The direct cause of mortality  for these pines are the beetles.  It is these beetle outbreaks and  these beetle infestations that  are killing the pines, but the  question becomes what's the  ultimate cause of mortality.  And this is where there's a  debate going on right now.  Many forest ecologists think  that climate is the cause, and  there may be a climate agent in  two different ways. 

 One is by moving towards warmer  and dryer summers.  These plants may be actually  shutting down their leaf  stomata.  A tree takes in carbon dioxide  from its leaf but it also loses  water from its leaf.  And so in dry summers these  plants will shut down their leaf  stomata to minimize the escape  of water.  But in so doing they're  effectively starving themselves  of carbon and carbon dioxide  which is a basic building block  for photosynthesis.  And so the consequence may be  they're actually sort of  starving themselves and  consequently not able to mount a  defense against this pest and  mount the chemical defenses that  these pine trees use in  defending against these beetle  outbreaks.  That's one possible climatic  cause.  The other possible climatic  cause is the fact with these  shifts towards warmer winters in  these areas this may not be  knocking back the beetle  populations as much in the  winter time so every winter  there's less and less knock back  of the beetle populations and  they're able to spread further  and gain more of a foothold in  the following years.  Again, with the understanding  there's variability around these  trends and there's year-to-year  variations.  But it should be clear and so  that's why this quote here is  from a meeting of forest  ecologists one argument putting  this point of view forward,  beetles are the bullet that's  killing the pines but drought  and climate variability may be  what's pulling the trigger here. 

 But it's also important to note  that there are counter  hypotheses in terms of the  overall re-growth of these trees  from earlier logging events, and  this may be sort of a natural  cycle of these trees and there  also maybe fire suppression  effects coming into play here.  So as always, one of the  challenges here is to make a  confident attribution yet, and  we're not at the stage where we  can fully make a confident  attribution of what's the actual  cause.  We have reason to suspect that  climate change is implicated  here but we don't have a  definitive statement at this  time.  Okay, one reason for that is  that the ecological impacts and  the ecological consequences, so  the second point here, of  climate change are still in the  pipeline.  They're sort of this causative  change that I'm showing up here  where greenhouse gas emissions,  and I'm sort of highlighting CO2  as the major component of  greenhouse gases that we emit to  the atmosphere and causing an  increase strengthening of the  greenhouse effect, the trapping  of long wave radiation, warming  of surface temperatures, that  leads to climate change and a  warming of the overall  atmosphere and oceans.  But there's a time lag to that.  The oceans and the atmosphere  have a thermal inertia to them  so driving our car today, the  climatic affects of that will  not be seen for several years to  decades because it takes a while  for that signal to transmit  itself through the climate  system.  Similarly, there is a lagged  response of the ecosystems, and  I'm focusing on vegetation here  but this is a broadly true  statement, that there is a  lagged response of ecosystems to  these warming.  It takes a while for species to  move around.  It takes a while for changes in  population abundances. 

 Some responses are relatively  fast, such as those shifts in  phenology and spring timing that  I showed you earlier.  Some, such as shifts in forest  belts and species distributions,  are relatively long.  And just to kind of show this  graphically, here we have this  is a record of carbon dioxide  concentration in the atmosphere.  The horizontal scale there is  years from 1000 AD at left to  2000 AD at right.  The vertical scale is parts per  million concentration of carbon  dioxide in the atmosphere.  You can see that for 1000 AD to  roughly 1800 AD carbon dioxide  concentrations in the atmosphere  were relatively level.  And then there's a very clear  signal of increases in carbon  dioxide over the last 200 years.  This is confidently contributed  to the start of the industrial  revolution, the burning of coal  and other fossil fuels for  energy and power and so forth.  That signal is incontrovertible  and it's been a signal that's  been well underway for several  hundred years now.  Now we get to where there's been  a lot of debate over the last  several decades, and I would say  with this most recent IPCC  report in 2007, this debate is  finally ending. 

 Certainly it's ending in  scientific circles where the  IPCC has stated that the warming  of the climate system is  incontrovertible and has made  statements with high confidence  that warming since 1975 is  likely caused by human  activities.  And so here with we can see here  this is the same time, a little  bit longer time scale, going  back to about 600 AD all the way  up to the year 2000 AD and now  the vertical time scale are  variations in temperature where  zero is a reference temperature  for representing the mean  temperatures from 1961 to 1990.  This is a summary for the  northern hemisphere.  And you can see that there's  variability, that there have  been relatively cold decades and  warm decades, cold centuries and  warm centuries.  And only now in the last  20 years or so has, and you can  sort of see on the far right  there, that black line, have the  temperatures been moving beyond  the range of variability.  And there is still a point of  debate going on here between  sort of the medieval warm  period, some of those warmer  intervals around 1000 AD  compared to the 20th century.  I think it's safe to say that we  are at least at present one of  the two most warmest time  periods on record and depending  on which way you want to argue  the data we are at or beyond  what we've seen for the medieval  warm period.  But again just to kind of go  back to the IPCC statement,  based upon this other analyses,  which I'm not going to go into  about the distribution of this  warming signal which is seen  worldwide, the fact the  distribution of this signal  vertically in the atmosphere  where the upper troposphere is  warming and the stratosphere is  cooling a bit.  These are all diagnostic  fingerprints of a human  causation, a greenhouse gas  causation and so the IPCC and  the global climatological  community has made, again,  statements with saying it's  likely that the human causation  of climate variability and this  most recent warming trends can  be confidently dated back to  1975 AD.  But now we get to this last  part. 

 We're really looking at the  ecological signals, and I've  showed you some studies where  people are arguing that we are  in fact seeing these early  ecological signals of climate  change.  But this is where the signal is  just emerging from the data.  Okay.  And one comment then, John gave  a very nice work-through of this  figure a moment ago.  He talked about how the red line  was the, this is the one actual  slide using model, climate model  simulations here.  As opposed to the data which is  everything I've been showing you  from this point and will keep  showing forward here.  These are again these climate  model simulations where the  black line is actually data,  that's the historic observations  from 1900 to 2000, and then the  different colored curves show  changes, projected changes in  temperature.  Again, the red line being more  of a business as usual scenario  where we don't take serious  steps towards reducing our  greenhouse gas emissions at a  national or international level.  The blue line representing more  of a place where we might be  able to get to with more serious  attempts to reduce greenhouse  gas emissions.  And then that yellow line, which  is one that John didn't spend  much time on but I'll note for a  moment here, is the warming  that's already in the pipeline. 

 This gets back to the point that  even if we were to shut down all  fossil fuel emissions today  there will still be maybe a half  degree warming still coming at  us.  And no one thinks we're going to  shut down all fossil fuel  emissions today or tomorrow.  This is more of a what-if  scenario.  And even in this what-if  scenario we still have this  warming, again, in the pipeline  and then the ecological  consequences from that warming  still coming down with some lag  after that.  This is a figure that I've seen  I don't know how many times or  variations on this figure.  In my career if you are working  on climate change in the area of  science or interest in the  impacts of climate change, these  kinds of projections you see  over and over again.  I like very much how John  connected to this figure using  the idea that the mitigation  community is trying to move our  range of possible futures from  the red curve to the blue curve.  The adaptation community is  thinking about how can we help  societies and ecosystems adapt  to the inevitable amounts of  climate change that are inherent  in even the most optimistic  scenarios represented by the  blue curve.  A way that I've tried to connect  to this is sort of tried to get  to this from a perspective of  thinking about what these  numbers mean and put it in sort  of a context of our lifetimes.  And so one context is in my  lifetime. 

 I was born in the early '70s  just actually at this point  when the IPCC sort of said that  we think we see a confident  signal of global warming being  caused by greenhouse gases.  Over my lifetime I might expect  to see a net change in global  temperatures of 1.4  to 2 degrees Celsius,  2.5 to 3.8 degrees Fahrenheit.  I have a 3-year-old.  She was born three years ago.  And she, in her lifetime, may  expect to see an additional  warming.  This is using averages here we  don't know how long any of us  have to live but using sort of  an average lifetime for the US  population, she might expect to  live until the 2070s, the 2080s  and might expect to see a net  1.8 to 3.5 degree Celsius  warming,  3.2 to 6.3 degree Fahrenheit.  And this is just really  astounding.  If you think about how much  change we'll actually see in our  lifetimes and our children's  lifetimes.  This to me is where these sorts  of analyses become very  sobering.  All right, so now I want to sort  of segue and talk about why I  think that these are such  significant changes and why we  should be concerned about them. 

 And I think one thing that, as  scientists commuting to a  general audience, to the general  public, 1.4 to 4.5  as a global mean temperature  increase, sort of the range of  temperature increases over this  century, doesn't sound like a  lot.  One reason is that scientists  use Celsius, most of the  American public uses Fahrenheit,  and it's about a five-ninths  conversion between the two so  you have to do a little mental  re-scaling there.  But then of course other big  reason is our own day-to-day  lifetime we see plenty of  temperature variances which are  far larger than that.  And that's sort of shown in  these three bars at right here,  where the biggest bar is sort of  the average range in  temperatures from the coldest  month of the year to the warmest  month of the year which is about  55 degrees Fahrenheit from about  January to August  or 30 degrees Celsius.  Daily temperature ranges of  course that various quite a bit  day-to-day, season-to-season but  you might see on average about  20 degrees Fahrenheit and  12 degrees Celsius or so.  And when you scale this against  those, the model, I'm sort of  flagging it as a modeled number  there, projections for this  century of, and I'm purposely  using the upper end numbers  there, of 8 degrees Fahrenheit,  or maybe 4-1/2 degrees Celsius,  that seems kind of  small by comparison, right?  So why are we so concerned as  climatologists, as ecologists  and others thinking about the  climatic impacts of these  numbers that are small relative  to the day-to-day and the  season-to-season ranges?  Well one answer of course  is that that number on the right  is representing a global average  where it's not just for  a single location, but it's  a change in the mean state  of the overall climate system  which has major affects upon  transfers of heat and the  operation of the climate system.  But another reason, which is  what I'll go into here, is what  we can know and document from  the relatively recent geological  record.  And now the time scale will be  focusing on the second part here  is the last 20,000 years or so.  The top plot there, this is  going from the time scale here  is years before present,  years BP.  So that's 22,000 years before  present at left all the way to  zero years before present which  is how paleoclimatologists talk  about today say zero years  before present. 

 And the vertical scale is  estimates of temperatures at  Greenland and from ice core  data up in Greenland.  And again using the zero  representing sort of a reference  modern day temperatures over  Greenland.  And so we can see in Greenland  our estimates in the  temperatures were about  10 degrees colder at sort of  full glacial conditions,  20,000-22,000 years ago.  There's a period of deglaciation  from about 16,000 to 10,000  years ago.  And you can see there's some  large oscillations along the  way; it's not a straight linear  transition.  And then over the last 10,000  years ago it's been a relatively  stable conditions at Greenland.  And those numbers right there,  worldwide the estimate is going  from 22,000 years ago to today.  Worldwide temperatures have  increased by about  5 to 9 degrees Fahrenheit, and  at Greenland again the estimate  is more like 18 degrees  Fahrenheit warming.  Because typically on all time  scales the temperature  variations we see in the high  latitudes, in the Arctic, is  higher than we see on a  worldwide basis.  So the point to take way here is  that global warming, that amount  of temperature change worldwide,  3 to 5 degrees Celsius,  5 to 9 degrees Fahrenheit,  is pretty similar in magnitude  to right there. 

 To what we're modeling for this  century.  So in terms of the magnitude of  change this transition from a  full glacial state to the  present day interglacial is  roughly equivalent in size to  what we're projecting for this  century.  Now you look at the bottom set  of maps, and I've just shown you  three sets of maps here.  21,000 years ago, 11,000 years  ago, today.  And this is mapping, and I'll  show some more maps of this in a  few minutes, mapping the percent  abundance of spruce pollen.  And I'll talk more about how  this works.  But what we're basically doing  is using the pollen grains we  find in sediments at different  locations looking at the  abundances of pollen from  different tree taxa and then  mapping out their distribution.  So you can see that 21,000 years  ago, and notice that there's a  large ice sheet over much of the  continent 21,000 years ago.  This is when we had ice over  much of Wisconsin except for  the driftless area in the  southwestern part of the state.  That ice starts melting back and  is effectively gone from North  America by about 6,000 years  ago, and as that ice retreats  and as temperatures warm, the  distribution of spruce pollen  and by implication the spruce  trees themselves is shifting and  it's shifting northward. 

 You see this whole shift in  range where there's almost no  overlap between where we find  spruce pollen 21,000 years ago.  You can sort of see in the  eastern US we find lots of  spruce pollen in glacial  sediments from around here.  And then today where most of our  spruce trees or spruce pollen  are in northern Wisconsin,  Canada and the boreal forest.  So we see these major shifts in  species distributions over this  time.  All right, so again just to kind  of make this point that this  last deglaciation, the climate  changes are kind of a good case  study, a good system to be  studying, we're thinking about  what might be happen over this  century.  We go from having ice melt, we  go from having large ice sheets  to only permanent land ice  over Greenland and sea ice, of  course, over the Arctic ocean.  As well as the ice sheets in  Antarctica.  And there's changes in carbon  dioxide during this time as  well.  So if you're interested in the  physiological responses of  plants and other organisms to  CO2, this is also a good time to  be looking at things where we go  from about 190 parts per  million, so vertical scale CO2,  horizontal scale, again, time  years before 2005.  We go from about 190 parts per  million CO2 at the full glacial  conditions to 270 parts per  million or so at the end of this  transitional period at the start  of the current interglacial that  we're in. 

 And then you can see that big  spike at right there, that's  what we've been adding to the  climate system, to the  atmosphere, since the industrial  revolution.  You can measure the height here  and in the height of that spike  at right and you can see they're  roughly the same magnitude,  80 to 100 parts per million.  Of course, we haven't stopped  putting carbon dioxide in the  atmosphere, we're going to keep  going up.  And so more and more we're going  to move well beyond the  magnitude that we've seen in  these geological time scales.  Okay, I'm going to now start  talking a bit more about what  the ecological and plant  vegetation responses to these  sorts of climate changes.  But I want to do a little  interlude here about method.  Since I know not everyone in the  audience is a paleoecologist who  works with these sorts of  things.  So I want to talk a little bit  why we actually use lake  sediments to study changes in  vegetation.  This is a photograph of Trout  Lake in northern Wisconsin.  And what we're interested in is  forest history. 

 Those responses of forest  communities and other plant  communities to climate change  over the last 20,000 years.  But those forests of course are  long gone and we have to find  some record or archive of them.  You can think of lakes as many  things.  You can think of them as habitat  for fishes.  You can think of them as very  sensitive canary in the coal  mine indicators of climate  change.  You can also think of them as  giant garbage pans in which  they've been sort of collecting  sediments and debris from the  watershed around them.  And that sort of garbage pan  capability is what makes them  very useful to us.  They have been collecting, among  other things from that  surrounding watershed, the  pollen and other plant debris  that has either been blown or  washed into that lake from the  surrounding plant communities.  Many plants, not all plants, but  many plants rely upon wind  dispersal, so they broadcast  large amounts of pollen into the  atmosphere.  That pollen, of course if you  have rag weed you've experienced  this firsthand, that pollen will  settle out across the landscape. 

 Some of it settles out in lakes,  travels down through the water  column and then will be captured  and preserved in the sediments  accumulating at the bottom of  the lake.  We can go out and take cores and  time series, such as shown at  right.  Where we're looking at three  different taxa, spruce, pine and  oak, and looking at the percent  abundance of these different  taxa over time.  Here's just a shot  of our operation.  You can see it's pretty simple.  A couple canoes and a platform.  We typically work with small  lakes where we do this all by  hand.  We might take 13 or 15 meters  of mud, and that 13 or 15 meters  of mud might represent 17,000  years because these lakes are  building up their sediment  slowly.  You might be not be able to see  it so well but there is darker  variations and lighter  variations that sediment core  that tells us something about  the depositional history and the  lake itself.  We can then extract the pollen  from these sediments, look them  under a light microscope. 

 This is where the grad student  person-power really comes in  handy because this is a  laborious process to count  multiple grains per multiple  samples taken from this  13 meters of mud.  But we can visually identify the  pollen grains by their  morphology, their shape, their  size, the sculpturing, the  number of holes they have in  their shell, the -- of the  pollen grain, and identify the  different pollen grains to  different pair of taxa.  We're typically working on sort  of a genius level working with  pollen data.  People have been doing this sort  of work for decades now,  collecting this data in the  database so each dot that  represents a site where we have  sediment record at that location  for these different time  periods.  You can see that as we get close  to the present we have more and  more data.  Old lakes are hard to find,  we look very hard for them.  And that's when we can make  these sort of maps here.  And we're going to switch now.  So what I just showed you were  static maps, I'm going to show  you the sort of animated form of  these maps.  And if I can find my cursor. 

 So again what we're looking at  here, just to give you an  orientation, the blue is a  Laurentide ice sheet.  And in fact, why don't we,  before we get to spruce itself  why don't we just do a general  geography map here.  Let's see.  There we go.  All right, let's not worry about  the plants first.  Let's just look at what's  happening to the ice sheet and  Florida.  Because what's going to happen  here as we move forward from  21,000 years ago to today ice is  going to melt and you're going  to see the blue area shrink and  you're also going to see Florida  shrink and the sea level rising.  You see how Florida is much  bigger then than it is today.  And then the dots are showing  where we have our different  sites for our fossil pollen  records.  It doesn't matter so much here. 

 So you can see the ice shrinking  away.  You can see sea level rises and  Florida shrinks to its present  configuration.  You know Florida is, and you  might notice how Florida is  shrinking quite a bit, but say  the west coast of the United  States is not changing that  much.  That's because there's a much  shallower slope in Florida,  right?  It's a carbonate platform,  it has a very gentle gradient  and so a meter of sea level  rise, let's say, can translate  to, I'm making up numbers here,  but a 6 or 7 meter larger shift  laterally because the slope is  so gentle, whereas a relatively  steep slopes on the west coast  result in relatively little  lateral change in coastline.  All that water in that ice sheet  results in about 100 to  120 meter, 400 feet let's say,  increase in sea level coming  from the last glacial period to  present.  By contrast, Greenland, the  amount of ice up in Greenland,  it's estimated that if we melted  Greenland that could be about  21, I'm sorry about 7-meters,  maybe 25 feet or so.  So that's just the background   geography.  Let's take a look at spruce now.  That's just sort of an aside  there.  So again to orient you here. 

 You see what happens with spruce  and with Florida.  Now with the green, the  coloring, the white are areas  where we didn't map the data.  We have some sites out there but  the site density is relatively  low so gray in this color scheme  are sites where we have sites  but there's little or no spruce  pollen found at those sites.  And then as you go to darker and  darker green there's more and  more spruce pollen found on  those sites, and by implication  we think more and more spruce  trees growing around those  sites.  So what's great about these maps  is that you look at them you can  see how what we think of as  static entities the forest  around us at these times scales,  given a climatic driver, are  actually quite dynamic.  Species do move as they track  their climatic optima, they  migrate across landscapes  following the range of  temperatures that they can  tolerate.  Now, of course, plants don't  pick up and move.  What's happening is that new  seeds and new populations are  established in areas that have  become climatically favorable  and then populations and stands  are dying out and areas have  become unfavorable, and the net  affect of the species level is  this migration and this shift  across landscapes.  And by the way, these animations  are available online.  If you just Google pollen viewer  you can find them and show them  off to your friends and family. 

 Okay, all right so that's one,  and again remember what we're  talking about here is on  a global scale about  3 to 5 degrees Celsius that has  caused these major shifts in  tree distributions and ice  extent over the last 20,000  years.  Another point is that species  don't move as blocks.  We don't see the sort of  migration, this is actually a  big debate in biogeography.  When climates, several decades  ago, when climate changes do  forests move at intact blocks?  No.  Instead what happens is you have  this resorting of species and  communities as each species is  tracking climate change in its  own unique way and you get this  reshuffling of communities and  new communities emerging.  One kind of nice example I use  to illustrate this point, here's  a range map for spruce on the  left, ash on the right.  You can see how today there are  areas of overlap but they're  largely disjunct from each  other.  Only sort of overlapping at the  range margins.  15,000 years ago, that's the map  here, their distributions are  actually very similar.  Pollen records that have a lot  of spruce in them, spruce pollen  in them, also tend to have a lot  of ash pollen, suggesting that  these were sets of taxa that  were much more closely  associated in the past than they  are today. 

 And this is just two of the  taxa.  We can look at over examples as  well.  So we see this reshuffling and  resorting and sort of high  abundance of spruce and ash in  the same communities would look  quite odd to us today but would  have apparently been the norm  during this time period here.  And one of the great ongoing  research questions is what  causes, what allow these taxa to  reshuffle and reform to our  modernized odd communities.  Another area that people have  been working on quite a bit  is looking for periods of abrupt  climate change and trying to  figure out how quickly can  plant communities respond  to those climate changes,  actually trying to quantify  these lags between climatic  change and ecological response.  A famous event is the Younger  Dryas, or YD as it's labeled  there.  Where this is, you might have  remembered during that  progression from colder to  warmer temperatures there is  return to cold temperatures  along the way in that Greenland  record, that cold interval which  lasts for about 1500 years is  known as the Younger Dryas, and  it's seen around the north  Atlantic and around much of the  northern hemisphere, and even  some places in the southern  hemisphere, we see this cold  interval.  And so the latest papers have  been suggesting that the Younger  Dryas termination may have been  this sort of abrupt ending of  this Younger Dryas cold period,  may have been within sort of  years to a few decades.  It's a very rapid event in our  paleoclimatic records.  And we can use it to study the  responses of plants and other  species to abrupt climate  change. 

 And what you can see here, so  the left hand record is a record  of organic sediments the lake  has lost -- is what that acronym  stands for.  And this scale here, the  vertical scale is older  sediments at the bottom, younger  sediments at top.  And this lake tends to be more  productive, has more organic  content in its sediments during  relatively warm intervals and  then during that Younger Dryas  interval when it's cold,  lake productivity shuts down.  There's little or no organic  carbon in those sediments.  And we have this nice indicator  of cold temperatures at this  site.  So the left hand record marked  by that percent LOI is a record  of lake productivity and, by  implication, lake temperature.  And then the right hand plots  are the percent abundances of  different pollen grains  corresponding to different plant  taxa growing on the landscape  around that lake.  And you can see that very  quickly where we have this  decrease in organic carbon and  temperatures on this site, we  see decreases in spruce and  birch abundances, increase in  sedges and maybe a smaller  increase in grasses.  We have a very quick change in  the plant community composition  from maybe more of a forest  tundra type of vegetation to  more of an open tundra sedge  grassland around that site.  And again the key point being  here this happens quite quickly. 

 That these climatic changes were  happening years to decades.  The ecological response is the  vegetation change in these  communities around these in  response to these climate  changes is happening on the  scale of decades, maybe a  century or so at most.  These are not, one of the big  debates has been how much  inertia is there in plant  communities and these sort of  records suggest that plant  communities can change quite  quickly in response to climate  change.  One of the interesting things,  if you look at these recent  geological records, is that  there's not many plant  extinctions.  Most species are not being  driven extinct by the climatic  changes we've seen over the last  20,000 years, the last 100,000  years, the last million years.  There are cases where there are  some.  You can definitely point to a  few.  But of course the famous wave of  extinction that happened during  this time period is the demise  of the mammoths and mastodons  and giant sloths and other large  mammals, large vertebrates in  North America.  There's a wave of extinction  that happened worldwide and  there's been a classic debate  that's been going back to Paul  Martin in the 1980s about what  killed the mammoths, what killed  the mega-fauna.  Was it climate change,  we're moving from colder  climates to warmer climates?  Was it human hunting?  And I think as with so many of  these debates, the answer is it  was both. 

 That it was a combination of  climate change reducing the  habitat area available to these  animals and reducing their  population sizes making them  more vulnerable to other  pressures, in this case for  these animals, the pressure of  human hunting, the arrival of  early Indians into North America  and the big game hunting culture  that came with that.  So just to kind of wrap up here,  what can we expect from  Wisconsin based on what we see?  And I'm giving you a very  general sense of answers here.  We expect, again, especially in    the more extreme climate  scenarios for this century, we  expect to see shifts in the  range in distribution of various  plant taxa.  We might expect that the various  pines and spruces of the  northern forests would diminish  in abundance and/or die out and  maybe increase in abundance up  in Canada.  We might expect to see other new  species, formally non-native to  Wisconsin, moving in,  immigrating into the southern  part of the state.  We expect to see changes in the  community composition in all  communities as some species  become more abundant under the  new climate regime, others  becoming less abundant.  And, more generally, we should  expect the unexpected.  We should expect there's new  species moving in, other species  are dying out.  That we see new webs of species  interactions and from these  interactions will be I think  some of our greatest surprises.  We have to have a lot of  humility as we think about what  will happen in the future. 

 We know that there are, under  these sorts of climatic  scenarios we project for the  future big ecological changes  are on our way.  We can make some first-order  predictions about them.  But when we get into these  species interactions, that's  when we have the least ability  to make confident predictions  about what will happen.  And we should really expect sort  of the unexpected in those  areas.  This is also kind of final pitch  for WICCI.  There really has not been much  work done at this point.  There's been David -- and UW  Forestry and others are the  exception to the rule, but by  and large at a state level there  has not been a very detailed  assessment of individual  localities and locations and the  response of these ecosystems to  the kinds of climate changes for  this century.  So this is what WICCI is really  trying to do, bring together UW  scientists and DNR scientists  and land managers to look at  these sort of changes, building  on the pioneering work of John  Magnuson and others, to really  give policymakers and citizens  of this state an understanding  of what we might expect or a  range of scenarios of what we  might expect in this state over  this century.  Okay, I'll stop there.  And I'll take questions, I'll  just note for a couple of things  I showed along the way, pollen  viewer, WICCI, IPCC, the easiest  way to find these things is just  to Google them and those strings  will track them down pretty  well. 

 Thank you again for your time.  [APPLAUSE]