A paper has appeared on 3 February 2006 in Earth Interactions titled
“Long-Duration Drought Variability and Impacts on Ecosystem Services: A Case Study from Glacier National Park, Montana” by Gregory T. Pederson, Stephen T. Gray, Daniel B. Fagre, and Lisa J. Graumlich
This paper further documents why we need to adopt a vulnerability paradigm as a more effective framework to reduce our exposure to environmental and social risks from climate variability and change, regardless of the relative contribution from natural- and human-climate forcings.
The abstract of the paper reads,
â Instrumental climate records suggest that summer precipitation and winter snowpack in Glacier National Park (Glacier NP), Montana, vary significantly over decadal to multidecadal time scales. Because instrumental records for the region are limited to the twentieth century, knowledge of the range of variability associated with these moisture anomalies and their impacts on ecosystems and physical processes are limited. The authors developed a reconstruction of summer (JuneâAugust) moisture variability spanning A.D. 1540â2000 from a multispecies network of tree-ring chronologies in Glacier NP. Decadal-scale drought and pluvial regimes were defined as any event lasting 10 yr or greater, and the significance of each potential regime was assessed using intervention analysis. Intervention analysis prevents single intervening years of average or opposing moisture conditions from ending what was otherwise a sustained moisture regime. The reconstruction shows numerous decadal-scale shifts between persistent drought and wet events prior to the instrumental period (before A.D. 1900). Notable wet events include a series of three long-duration, high-magnitude pluvial regimes spanning the end of the Little Ice Age (A.D. 1770â1840). Though the late-nineteenth century was marked by a series of >10 yr droughts, the single most severe dry event occurred in the early-twentieth century (A.D. 1917â41). These decadal-scale dry and wet events, in conjunction with periods of high and low snowpack, have served as a driver of ecosystem processes such as forest fires and glacial dynamics in the Glacier NP region.
Using a suite of paleoproxy reconstructions and information from previous studies examining the relationship between climate variability and natural processes, the authors explore how such persistent moisture anomalies affect the delivery of vital goods and services provided by Glacier NP and surrounding areas. These analyses show that regional water resources and tourism are particularly vulnerable to persistent moisture anomalies in the Glacier NP area. Many of these same decadal-scale wet and dry events were also seen among a wider network of hydroclimatic reconstructions along a northâsouth transect of the Rocky Mountains. Such natural climate variability can, in turn, have enormous impacts on the sustainable provision of natural resources over wide areas. Overall, these results highlight the susceptibility of goods and services provided by protected areas like Glacier NP to natural climate variability, and show that this susceptibility will likely be compounded by the effects of future human-induced climate change.â?
Since even ânatural climate variability canâ¦â¦. have enormous impacts on the sustainable provision of natural resources over wide areasâ? the prudent approach to reduce the risk is to plan for the reoccurrence of historical- and paleo- extreme events.
As reported on the Climate Science weblog (e.g. see and see ), and in our peer-reviewed papers (e.g. see ), the vulnerability paradigm is a more robust approach to assess the threats associated with climate variability and change than relying on the narrow perspective of the multi-decadal global climate prediction models.