MTNCLIM 2005 FROM A PALEO PERSPECTIVE. G.M. MacDonald UCLA

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1 MTNCLIM 2005 FROM A PALEO PERSPECTIVE G.M. MacDonald UCLA

2 This is the Powerpoint presentation of a summary talk for the 2005 MTNCLIM Meeting. The presentation was to have provided a synthesis of the meeting from a viewpoint that integrated both modern and paleo studies. The presentation is dedicated to the memory of Dennis Machida. This is an educational presentation only and all images are copyrighted and not to be reproduced

3 Three themes regarding progress on mountain climates are explored - Coherence Uncertainty Ways Forward

4 COHERENCE Long climatic records display variability that is greater in magnitude and duration than that anticipatable from instrumental records. These records are now being assimilated and used by the larger community. This shows coherence in the paleo record and also in the concerns of paleoclimatologists and modern climatologists, ecologists and resource managers.

5 The occurrence of a large Medieval mega-drought that impacted almost all of western North America and is without precedent in the historical period is a coherent signal seen in many types of paleo records. It provides evidence of extreme the range of natural variability can be. E.R. Cook, C.A. Woodhouse, C.M. Eakin, D.M. Meko and D.W. Stahle, 2004: Long-term Aridity Changes in the Western United States. Science, Vol. 306

6 The mega-drought impact extended from mountains in Canada to California and provides an extreme scenario for resource management Case and MacDonald 2003

7 Eric Kuhn s talk displayed how resource managers have integrated paleo data from another widespread drought that occurred in the 16 th century Stahle et al. EOS

8 COHERENCE Paleoclimatologists are developing longer high resolution multi-proxy climate records that span the entire Holocene and are similarly being incorporated into the work of climatologists, ecologists and resource managers working with contemporary questions.

9 The work of Jeffery Stone and Mark Shapely presented at MTNCLIM demonstrate the high resolution and sensitivity of Holocene paleo records from lakes.

10 Quercus turbinella Aber et al 2001 Bioscience Ron Nielson s talk demonstrated how mid-holocene distributions of tree species can be incorporated to help understand potential future global scenarios.

11 COHERENCE Long term climatic records are now accumulating in spatial networks and show consistent patterns of regional and temporal variability. These insights help inform us of spatial patterns in climate variability that are likely to occur today and in the future

12 The talk by Stephen Gray provided examples of regional patterns of past environmental change that are important in understanding current conditions in the western mountain region Gray et al GRL 2003

13 COHERENCE Instrumental and paleo climatic records are showing evidence of the same potential ocean-atmosphere drivers.

14 Reconstructions of the PDO provide a coherent picture of this phenomena and also indicate that it is prone to variability in its frequency and intensity MacDonald and Case In press GRL Megadrought

15 Materials presented by Emma Watson and Greg Pederson illustrated how modern climate patterns can be integrated with glaciological and tree-ring research Pederson, Fagre, Gray, Graumlich, 2004 GRL

16 UNCERTAINTIES We still do not often fully understand (or adequately appreciate the complexity of) the linkages between climate and ecologicalevolutionary responses in the modern and paleo data sets.

17 Information presented in talks or posters by the researchers listed below are just some of the examples of work that highlighted the complex nature of the relationship between climate and ecosystems Malcolm Hughes Brandi Bracht Tom Whitham Craig Allen

18 UNCERTAINTY We do not fully understand the often non-linear dynamics between potential climatic drivers. We do not understand the underlying forcing factors of the ocean-atmosphere drivers of variability

19 Work by Stephen Gray highlights the complex linkages in the ocean-atmosphere system Gray et al 2003 GRL

20 UNCERTAINTY Despite all our progress in modern climatology and paleoclimatology, in terms of bidecadal to multidecadal to centennial droughts the only thing that is certain about the future is uncertainty.

21 Based on paleo records we cannot yet build models that predict or retrodict the occurrence of prolonged severe droughts despite the occurance of such droughts in our records and in the historical period

22 Based on paleo records and inturmental climate records we cannot predict if the current drought in the Colorado Basin will end next year or 1000 years from now

23 Based on paleo records and modern instrumental data no one predicted that the winter would have broken the 100-year precipitation record in southern California Southern California Precipitation

24 WAYS FORWARD 1. Higher temporal and spatial resolution records to more closely link both long and short term records with modern processes (lapse rates for example Jessica Lundquist) in critical sites. 2. More integrated paleo and modern networks of uniform observations aimed at specific substantive questions (many here) 3. Greater model development and model-data integration for testing and hypothesis generation both climatic and ecological (Hughes, Mitch Plummer, Ron Nielson, Alex Hall etc.) 4. More molecular genetic work genotypes are more real than species and we are not seeing them (Whitham) 5. More international participants Canada AND Mexico in particular (but lets not forget Alaska ) 6. More graduate students in the fold because they will think of things we cannot imagine!

25 The future s uncertain and the end is always near Jim Morrison (UCLA 1965) This was the original ending slide for the presentation and made in reference to climate change and western mountain systems. I could not have guessed that these words would be so poignantly and sadly applicable beyond that context.