|
The Association Upcoming Meetings:
10th
CAVEPS and Quaternary Extinction Symposium CANQUA June 5-8, 2005 2nd
International Congress
The Quaternary Times Directory of Quaternary Scientists 2005 Northeastern Friends of the Pleistocene meeting Quaternary-Related Journal Discounts Quaternary Job Opportunities Quaternary-Related Abstracts Quaternary-Related Links Society of American Archaeology Fellowship Announcement Search the AMQUA Site
|
For me, northwest Arkansas was a new experience, and it was great to see it through the eyes of local field-trip leaders. Again, many thanks to Robin Webb and the Program Committee and to Peggy Guccione and the Local Organizing Committee for their hard work at producing a very successful meeting. The meeting theme, climate variability, is especially provocative this year, as we brace ourselves for a summer of drought and wildfires. Inasmuch as our discipline sees present and future changes through the lens of the past, we are uniquely qualified to comment on the precedence of current conditions. Two observations made at the meeting seemed especially apt: We know for certain that climate changes, and our data show that the Earth has experienced both warmer than-present conditions and episodes of rapid climate change. While these periods are not necessarily analogues for the future, they are instructive in revealing the magnitude of biotic and abiotic adjustments that can occur. Given the information we hold, it seems that we have an obligation to better communicate these insights to the public. After all, the abrupt shifts in ocean and atmospheric circulation seen in the past and their attendant changes on drought, fire, and sea level would be unimaginable in terms of cost to life, property, and livelihood were they to occur today. One of the great strengths of our discipline is the utilization of both computer model experiments and observational data in our research. Model-data comparisons allow us to treat the past as a set of natural experiments by which we can study earth system responses to a range of climatic forcings. For example, what happens to the climate system when Northern Hemisphere summer insolation is higher than at present, when atmospheric CO2 levels are less than today, or when thermohaline circulation shuts down? Models provide the hypotheses; the abiotic and biotic record provides the test of those hypotheses, which stimulates further model development. A result of this iterative strategy is that our discipline has shifted away from deductive approaches, which aim to understand the big picture based on multiple specific sites, towards research that frames questions in an inductive, top-down fashion, starting with the large-scale controls of climate change. For example, in the past we might have used eolian deposits at a number of locations to infer past atmospheric circulation patterns. Now, such data are employed to test the validity of particular model simulations. The question becomes how is it possible to have westerly winds in the Midwest during the LGM when model simulations of that period suggest strong glacial anticyclone circulation and surface easterlies? Unraveling such puzzles forces us to be precise and explicit about our assumptions and to consider the spatial and temporal limitations of both data and models. The resulting insights have been critical for assessing the relative influence of natural and human induced climate changes at present. Beyond their use in model validation, our data record the variability of climate change. Instrumental, historical, and annual-resolution proxy data sources show the uniqueness of the last century's climate. In prior centuries, when human influences on climate were less obvious, our records reveal that there was also substantial variability of climate on decadal and century time scales. Our data illustrate the rate at which systems adjust to climate change. Pollen records, for example, suggest that species ranges can change rapidly, especially when the disturbance regime is altered. Past rates, while impressive, pale against the speed at which species will have to disperse in the future to maintain equilibrium with projected climate changes. Moreover, the adjustment of organisms and physical systems will have to occur within already highly fragmented, human-modified landscapes. Our insights based on the past are an important message for current and future conservation efforts. In addition, our data reveal the relatively ephemeral nature of present-day biologic, geomorphic and hydrologic conditions. In most regions, modern forests represent an association that has existed for less than three millennia. In my neck of the woods, this means that the forest dominants have been in their present communities for only a few generations. Although we speak of old growth forests, it is the trees that are old, not the forests. Species have responded individualistically to past environmental changes, and in the process plant associations have been dismantled and reformed. We should make it known that old-growth forests are remarkable, not for their age, but because their current complexity and diversity arise from species' adjustments to inexorable climate change. Finally, our data show that natural disturbance is also closely tied to climate, and as climate has varied, so too has the disturbance regime. Management and land-use decisions focus on restoring ecosystems to their condition at the time of Euro-american settlement. Yet, our data sets show that the climate and disturbance regimes of that time period are just a sampling of the range of conditions possible in ecosystems. We know that it would be impossible to recreate landscapes that existed at some point in the past, even if we could describe them perfectly (which we cannot) or knew the role of Native American activity precisely (which we do not). We are in a position to argue that natural ecosystems are best managed as dynamic systems, which includes the possibility of changes in species' range and abundance and in disturbance regimes in the face of changing climate. The Quaternary community needs to examine its role in the current scientific and public discussions of human-induced environmental change. It is time for us to think of our research as applied rather than basic science done for its own sake. Ecosystem managers and planners are making decisions that influence the course of land-use and conservation policies for the next century, but in most cases these decisions are done without consideration of potential climate changes. For example, in the Pacific Northwest, the federal Northwest Forest Plan and the even more ambitious Interior Columbia Basin Ecosystem Management Project contain no provision for climate change in their recommendations for the future. Why is that? One explanation may be that our data are not accessible. Are we publishing in venues that are read by decision makers? Are we providing the types of information necessary to direct policy? I think not. We can do a better job of conveying information that is useful to planning efforts at both local and regional levels. Whereas projected impacts of climate change at a global scale are widely appreciated, we have done little to communicate how global changes affect the protection of reserves or the management of public lands at smaller scales. AMQUA can and should be at the forefront of such outreach efforts. Our wisdom is too important not be heard. In addition to the science of our research, we should address its application at professional meetings, in classrooms, and at land-use planning and policy meetings. We should talk to the media, environmental groups, friends, and family. If you do one good deed this year, think about writing or delivering a paper to an audience that you normally don't address: a conservation journal, a letter to the editor, a popular science magazine, or a web page. Persuade others of the value of Quaternary studies as an applied science.
Cathy Whitlock
|