TELLURIDE – Coral reefs can now be read like tree rings or glacier ice, mapping environmental change over time. What emerges from these sea core samples, besides climatic shifts, is a scientifically-deduced history of human land use practices spanning the past couple of hundred years. Studies of coral reef systems in Australia and Western Africa indicate that western-style agricultural practices, introduced by Europeans, caused large-scale sustained stress upon reef systems that are as impactful, if not more, than the usual suspects of over-harvesting, mining, and tourism.

In the next Pinhead Town Talk at the Palm Theater will be tonight, at 6 p.m., as co-author on the leading papers on this topic, Julia E. Cole, University of Arizona associate professor of geosciences and atmospheric sciences, will discuss a range of threats to oceans that people don’t typically consider.

Titled “Rough Seas: How the ocean is responding to climate change,” this talk is brought to Telluride free of charge by Pinhead Institute and Mountainfilm, in partnership with the Telluride Science Research Center (TSRC). The Town of Mountain Village is sponsoring the event and it is hosted by Nana Naisbitt, executive director of TSRC, and Justin Clifton, director of Mountainfilm on tour.

In a visual presentation, Dr. Cole will highlight the biodiversity richness of coral reefs along with her scientific findings, while Mountainfilm shorts will immerse the audience in oceanic experiences. Her extensive research has shown that ocean temperatures have risen two-degrees since 1801, and she is busy trying to ferret out what is caused by natural cycles such La Nina and El Nino and what is caused by changes in human activity.

“Modern agriculture has transformed Earth’s surface,” she wrote in the scientific journal, Nature, “and one consequence has been the increase in continental material that is eroded and transported to the oceans. There it poses particular hazards to reef-building corals, by decreasing the availability of light and interfering with feeding.”

Enhanced sedimentation due to agricultural practices is one significant stressor to coral reefs; another is the changing chemistry of the oceans, caused by the changing chemistry of the atmosphere. Human produced emissions of carbon dioxide (about seven metric tons annually), is adversely affecting the oceans.

Oceans are one of nature’s “sinks,” or absorbers, of carbon, but that service is not free of costs in today’s heavy carbon climate. While the current measured change in the chemistry of the oceans is small, the impact is not.

“It has dire consequences,” Cole said. “Coral reefs and sea creatures with carbonate shells (like tiny plankton – the beginning of the ocean food chain) are particularly sensitive to changes in carbon chemistry.”

Cole's research centers on expanding our view of recent climate variability. She utilizes geological and biological indicators along with instrumental records and climate models. Cole is developing geochemical records from long-lived corals, and studies the variability and impacts of large-scale climate systems throughout the tropical ocean.

The research of Cole and her colleagues is sponsored in part by the U.S. National Science Foundation, the National Oceanic and Atmospheric Administration, the Swiss National Science Foundation, and the Australian Research Council. Cole is also an active participant in the ongoing major scientific conference, the “International Coral Reef Symposium,” which has been held every four years for the past 30 years and focuses on assimilating the most recent and best scientific knowledge available about coral reefs worldwide. Cole and her husband, Jonathan Overpeck, also a professor of geosciences at the University of Arizona, live at Trout Lake in the summer months with their two children.

For more information about the Town Talk, please call Nana Naisbitt at 708-0004 or email at nana@telluridescience.org or visit www.pinheadinstitute.org. For more information about Mountainfilm, call Justin Clifton at 728-4123.