• University of Texas

• GEO 401

40 pts total Go to https://paleo-co2.org/ The panels on the homepage show plots of CO2 and temperature change through time. Read the axes carefully- there is a lot of information shown here! The plot in the lower right shows atmospheric CO2 levels as determined from ice cores (in black) and recent, directly observed, CO2 change (in red- these are hard to see, they plot on the far right side). The glacial-interglacial cycles can be seen. There is a zoom function on the bottom left panel that may help you (You can only zoom in on the bottom left panel). If you zoom in to low CO2 (on bottom left panel) glacial-interglacial cycles on the plot in the lower right will be easier to see. 1. Describe, qualitatively, how CO2 and temperature are related on both glacial-interglacial timescale during the Pleistocene (plots on right) and over the entire Cenozoic Era (plots on left). 4pts 2. Based on the data shown, when was the last time that atmospheric CO2 levels were persistently higher than they are today? 1pt 3. Now we will use data on these plots to make estimates of climate sensitivity. Fill in the table below using the plots on the right showing the Pleistocene Epoch. 4 pts CO2 (ppm) Temperature (°C) Glacial maxima Interglacials Use the data in this table to calculate climate sensitivity on a glacial-interglacial timescale. First calculate the number of CO2 doublings. You can do this with a log base 2 function. For instance, log2(2) =1, log2(4) = 2, log2(8)=3, etc. There are various calculators on the internet that can calculate the logarithm base 2 of a number (for instance, https://www.omnicalculator.com/math/log-2).