Deep sediments are unparalleled record of biotic changes over past 200,000+ years
University of California, Berkeley, scientists are drilling into ancient sediments at the bottom of Northern California’s Clear Lake for clues that could help them better predict how today’s plants and animals will adapt to climate change and increasing population.
The lake sediments are among the world’s oldest, containing records of biological change stretching back as far as 500,000 years.
The core drilling is part of a unique, multifaceted effort at UC Berkeley to determine how Earth’s flora and fauna responded to past changes in climate in order to improve models that project how life on Earth will adapt to today’s environmental pressures. What the researchers learn from their look-back in time will be crucial for state or local planners clamoring for better predictive tools to guide policies crucial to saving ecosystems threatened by climate change.
“We are reconstructing the past to better forecast the future, because we need to know what’s coming in order to adequately prepare for it,” said project leader Cindy Looy, UC Berkeley assistant professor of integrative biology.
Looy and 16 other UC Berkeley faculty members – including paleontologists, pollen experts, botanists, ecologists and climate modeling experts – will examine the lake cores for pollen grains, charcoal and fresh-water organisms going back at least 130,000 years, long before humans arrived in the area. Using isotope and chemical analysis as well as carbon dating, the researchers will obtain a long series of detailed snapshots – ideally, every 10 years – of the plant and animal communities in the Clear Lake area and how the communities changed in response to “natural” global warming events. The analysis will also provide a measure of the temperature, oxygen content and nutrient levels of the lake, which reflect rainfall and water level.
“One way to check our predictions is to go back in time to a state very similar to today, with the same plants and animals and about the same temperature. The fossilized plant and animal remains from Clear Lake will give us a baseline for what this region of California looked like under similar climatic conditions, and when it was colder or warmer. We use that information to fine-tune predictive models being developed today,” Looy said. “Rates of global warming almost as fast as what we see today last happened during the shift from the last glacial to the current interglacial roughly 12,000 years ago, so that is one time intervals we will focus on.”