The Laf

Issue date: 11/10/06 Section: News

Media Credit: Jared Kreiger If global warming sets in, Lafayette students may find themselves under water-not snow- come January

Despite what the producers of The Day After Tomorrow might tell you, a new ice age isn't suddenly going to take the world by surprise and wipe out civilization. On the contrary, global climate change takes place over all kinds of timescales, ranging from several decades to millions of years.

However, The Day After Tomorrow did get one thing right: the surface temperature of the world's oceans acts as the primary indicator for the global climate as a whole. And it is fluctuations in these temperatures over the past five million years that Kira Lawrence, assistant professor of geology and environmental geosciences, is receiving a $96,660 grant from the National Science Foundation to study.

The money from NSF will cover the costs of running Lawrence's laboratory and paying a number of students who work with her on the project.

Lawrence plans to use microscopic algae to study changes in the earth's surface temperature. These photosynthetic organisms sequester carbon dioxide from the atmosphere, which affects global temperature.

These algae also produce different types of organic compounds, specifically lipids (fats). According to Lawrence, there are two types of fats she is interested in, because their production is temperature sensitive. The relative abundance of these fat compounds, called alkenones, is expressed in a ratio, which can be related to the surface temperature of ocean water. These fats are difficult to break down, so they eventually end up deposited on the sea floor along with other organic matter.

Lawrence plans to collect core samples - cylindrical blocks of dredged up mud - from the sea floor and test them for abundance of organic matter, specifically the fats released by algae. Using that information to tell her what the temperature of the ocean surface was millions of years ago.

Lawrence said she will be able to use the data to "reconstruct ocean temperature over time." This allows her to examine the temperature trends over time, and thus study how the global climate has changed over time. She is focusing specifically on the time period between approximately three and five million years ago, a time when the world's climate shifted significantly.

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