Abrupt Climate Change: Causes and Ecosystem Responses

U.S. Geological Survey (USGS) scientists who study trends in climate change will be presenting the results from new studies at a workshop held in Pacific Grove, California, May 13-16, 2007.

In popular movies, freak tornados tear the “Hollywood” sign from the hills above Los Angeles and New York City is flooded and frozen. Both events are in response to abrupt changes in the global climate. While the events depicted in the movie are overly dramatic, there are real, if less exciting, responses to relatively rapid changes in climate that are currently taking place. In the west, trees are flowering earlier in the year, affecting the animals that rely on them as a food source; there is less snow in the Sierra Nevada, and it is melting earlier in the year, leaving less water available for irrigation in the summer; and flood events and winter storms are increasing in intensity. Evidence from past rapid changes in climate is being used to project possible responses to future rapid, large-scale changes in temperature and precipitation. USGS scientists use a variety of tools to uncover evidence of abrupt climate change including tree-ring patterns, ocean and lake sediments, geochemistry, micropaleontology, and climate modeling. The ecosystem responses to these rapid changes in climate are the topic of the 23rd Pacific Climate Workshop (PACLIM) which will be held May 13-16, 2007.

Organized and partially funded by the USGS, the conference brings together university, state, and federal government scientists from around the country for presentations and discussions on various aspects of climate variability, from the impact of rapid warming on the Sierra Nevada snowpack and the role of sea surface temperature in the drying of coastal California, to the record of freshwater variability over the past several thousand years in San Francisco Bay marshes and changes is vegetation distribution in the southwest and indicators of a possible warmer future in the western U.S.

As noted in the schedule below, USGS scientists will be presenting the results of new analyses on the connection between sea surface temperatures in the North Atlantic Ocean and precipitation in the Great Basin (Benson), the increased risk of flooding in a warmer world (Dettinger, Cayan, Florsheim, and Lundquist), changing in storm intensity and frequency in southwestern California (Miller, Mahan, McGeehin, Barron, and Owen), vegetation response to rapid climate change (Shafer, Bartlein, Edwards, and Hostetler), and the impact of climate change on the Navajo Nation (Redsteer).