Faculty members gathered yesterday at the Faculty Club to hear Dr. Bonnie Jacobs from the Department of Geological Sciences speak on “The Fossil Planet Record of the Climate Change in the Geologic Past: Relevance to the Future.”

Jacobs, the founder and chair of SMU’s Environmental Sciences program, who has received grants from the National Geographic Society and the National Science Foundation, is currently researching past climate change by studying plant fossils in Chilga, Ethiopia during the dry season in winter.

Currently, most of North America and Europe’s climate changes are known, but Jacobs noted that there is a large gap, referred to as the Palogene, in climate history for other regions such as Africa, that spans from 65 to 24 million years ago. This period of history occurred when Eurasia had yet to hit Africa and was when many important climate changes took place.

“We still want to find out more about the landscape,” Jacobs said. “What we’d like to do is fill in the gaps for Africa and then South America.”

Jacobs said that because of the gap in fossil records, there is always something new to find.

“The place is so full of fossils that within 10 minutes of our arrival, we found our first leaf,” she said.

Climate records can be obtained through examination of various plants, because they are sensitive to change and only grow in certain areas. Researchers look at the requirements for modern day plants to see where they would have grown in the past. According to Jacobs, the tropics are ideal places because they are located where the sun has the greatest impact.

“To understand Earth’s past climate adequately, we need to understand the nature of tropical past climate,” Jacobs said.

Jacobs also discussed how the size and shape of a leaf could reveal rainfall patterns. A larger leaf indicates more rain. By looking at leaf sizes and the locations of plants that growing today in Africa, Jacobs and her team believe that the area near Chilga is now experiencing a longer dry season than in the past.

Using this data, Jacobs hopes to one day be able to look at past climate changes and use them as a reference to identify the source of today’s climate changes.

“Unfortunately, we really can’t evaluate global warming directly,” Jacobs said. “Climate is a dynamic system that is always changing. I hope in the future, with more work, that we’ll be able to understand the whole system.”