800,000-YEAR CARBON DIOXIDE AND TEMPERATURE RECORD
FIGURE 14.7 Cores of ice drilled from the Antarctic ice cap by several research teams (photo) provide insights into past climates and concentrations of atmospheric carbon dioxide. The two graphs show that increases and decreases in air temperature (upper panel) correspond to increases and decreases in levels of atmospheric carbon dioxide (lower panel) recorded in Antarctic ice over the past 800,000 years. (Data from Lüthi et al., 2008)
(CarstenPeter/National Geographic/Getty Images)