1. Copyright 2008 ADDITIONAL PROXY DATA FOR STUDYING CLIMATE CHANGE

2. Copyright 2008 Sediment Cores from the Ocean Floor Photo credit: Ocean Drilling Program, Texas A&M University

3. Copyright 2008  18 O of seawater increases during cooler periods And decreases during warming periods Scientists can learn about past climates from microscopic fossils in the ocean cores Foraminifera (“forams”) Single-celled marine animals Some planktonic, some benthic Widely distributed in the oceans Very good preservation as fossils in ocean sediments Shells made of CaCO 3  18 O record of ocean water Photo credit: M. Manighetti & L. Northcote, Water & Atmosphere Online, New Zealand Institute of Water & Atmospheric Research

4. Copyright 2008 Speleothems Because speleothems (cave formations) such as stalactites grow in annual layers or “rings”,  18 O ratios in their CaCO 3 can be used to study past climate. Photo © Paul Williams, New Zealand National Institute of Water & Atmospheric Research Photo: Dave Bunnell

5. Copyright 2008 Studies of Modern and Fossil Plants Leaf shapes & surfaces from fossil leaves can be used as palaeoclimate indicators – as with modern leaves, certain shapes are associated with warm or cold climates. Density of leaf stomata (pores) can indicate ancient atmospheric CO 2 levels. Because plants take in CO 2 through the stomata, more stomata are needed if CO 2 levels are low, and fewer if the levels are high. Tree ring width can indicate ancient climate, and annual tree rings can be used to determine the time in the past. Photo credit: Woudloper Photo credit: Patricia Miller Photo credit: Dartmouth Electron Microscope Facility Photo credit: Menchi Photo credit; Hannes Grobe

6. Copyright 2008 Using computer models for “hindcasting” of recorded climate observations Illustration from Prof. Alan J. Thorpe, 2005, on behalf of the Institute of Physics. Illustration © Institute of Physics and IOP Publishing Limited (“IOPP”) 2006

7. Copyright 2008 Natural variations alone do not explain observed trends & a model incorporating both natural and anthropogenic factors yields the best fit Illustration from Prof. Alan J. Thorpe, 2005, on behalf of the Institute of Physics. Illustration © Institute of Physics and IOP Publishing Limited (“IOPP”) 2006

8. Copyright 2008 6 Foraminifera photo & δO-18 plot adapted from B. Manighetti & L. Northcote, Water & Atmosphere Online,

9. Copyright 2008 7 Illustration courtesy of Teachers’ Domain. Source: Zach Smith, Wright Center for Education, Tufts University