Final answer:
The average temperature change in the Arctic and Antarctic today is much colder compared to the Cretaceous period.
Step-by-step explanation:
The average temperature change in the Arctic and Antarctic today relative to the Cretaceous is significantly higher. The map in Figure 24.9.5 shows that the Arctic has experienced the greatest increase in temperatures during the first decade of the 21st century. Additionally, Antarctic ice cores have been collected and analyzed, revealing periodic cycles of increasing and decreasing temperature over the past 400,000 years.
During the Cretaceous period, which occurred approximately 145 to 66 million years ago, the Earth's climate was much warmer than it is today. The average global temperature during the Cretaceous was significantly higher than the present temperature in the Arctic and Antarctic.
Therefore, the average temperature change in the Arctic and Antarctic today is much colder compared to the Cretaceous period.