YOUNG SCIENTIST AWARD (DONATH MEDAL) LECTURE

One of the great joys of our profession is the ability to work on topics that interest us. We can “change jobs” many times throughout our careers without ever having to change our job title (or office). I have “changed jobs” several times already in my still young career, and I find these shifts very invigorating. My PhD work focused on the then-nascent stomatal proxy for reconstructing paleo-CO₂. While presenting this work at the 2001 Paleogene conference in Powell, I got to talking with Peter Wilf about temperature and rainfall proxies based on leaf shape. Peter offered me a post-doc position to explore these topics and of course I said yes! This conversation occurred outside a dusty bus that was stuck in mud in the middle of the desert. I am probably the only meeting participant that was happy for this delay. Lately, I have been putting two and two together and thinking about climate sensitivity; that is, what is the quantitative relationship between atmospheric CO₂ and global surface temperature? The CO₂ and temperature records are of sufficient quality and quantity now that such an exercise is possible for some parts of the geologic record. Here, I hope to share with you some of the more exciting developments in this frontier area.