Sitting along the banks of the Santa Cruz River, about 50 miles south of Tucson, the 200-year-old San Jose de Tumacácori mission holds rich tales of native cultures, European religious settlements and battles with Mother Nature.
In recent years, heavier-than-usual rainfall eroded the mission's adobe walls, threatening the monument and its link to southern Arizona history.
Now a team of researchers that included a scientist from the University of Arizona has produced a strategic guide to help the National Park Service anticipate and respond to the effects of environmental changes on the mission and other cultural sites across the country.
"The goal of the report was to figure out how to protect these representations of our history that tie us to our past and tell us about our past," said Alison Meadow, a staff scientist at the UA's Center for Climate Adaptation Science and Solutions.
The report, "Cultural Resources Climate Change Strategy," defines the effects of climate change on different cultural resources and provides methods for evaluating these sites and prioritizing options to protect them.
The National Park System is the lead federal agency for protecting and managing cultural resources — physical records that shape our identity as a country and provide evidence about how past generations responded to global change.
"Climate change is the biggest challenge the National Park Service has ever faced," National Park Service acting director Michael Reynolds said. "Climate change poses an especially acute problem for managing cultural resources because they are unique. Our cultural resources are the things, the places and the ways of living that remember our past and shape our identity. Once lost, they are lost forever."
Climate change impacts include rising sea levels and storm surges that threaten some coastal fortifications, historic cemeteries and prehistoric shell middens. In the West, changing precipitation patterns and flooding have deteriorated the Tumacácori mission and other adobe structures. At higher elevations, warmer temperatures and snowmelt have exposed wooden and bone tools to air, causing the artifacts to decay.
Meadow helped create a series of tables for the report that identifies a full range of climate changes and their impact on archaeological sites, buildings, museum collections and other resources over time. The tables motivate continued research and are expected to evolve with the development of new climate change knowledge.
"Through the tables and case studies, the report provides guidance and support for the park resources managers who protect these important cultural resources," Meadow said. "It is important to remember the National Park Service protects public spaces of all Americans. These are our gems."
The agency manages more than 400 monuments, parks, historic sites and memorials, including such iconic destinations as Yellowstone National Park, the Vietnam Memorial, the Liberty Bell, Mount Rushmore, Mesa Verde cliff dwellings, Ellis Island and historic battlefields, as well as lesser-known sites throughout the country.