Past climate changes
Open the Climate Trends learning tool again and select temperature. Use the horizontal scrubber bar to shorten the time period of the graph until you see the event "Medieval Warm Period."
Even though the Earth's temperature in the "Medieval Warm Period" was only slightly warmer than other time periods, it had a dramatic impact on life on Earth. Using the rollover tool, estimate the difference between the highest and lowest temperature that occurred in this time period. Click the box below to see if the difference in temperature that you found is correct.
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The highest temperature anomaly in the Medieval Warm Period (measured in units of temperature change from the 1960-1990 average) was about 0.2°C and occurred roughly 1100 years ago. The coldest temperature anomaly measurement in this period was roughly -1.5°C and occurred 737 years ago. The difference between this period's highest and lowest average temperature was therefore approximately 1.7°C.
Between approximately 335,000 and 322,000 years before present, ice core data displays a significant rise in temperature. Use the slope tool to find the rate of temperature change during this period of warming. At that rate, how many years would it take for the Earth's temperature to change by 3°C? Click the box below to check your work.
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Turn on the temperature data and zoom in to the time region in the question (enter the values into the left and right hand boundary boxes). Using the slope tool, you can determine that the rate of temperature change for this period is approximately 0.001°C per year. By dividing 3°C by your slope value, you find that it would take roughly 3000 years for the temperature to increase by 3°C at this rate. Answers may vary by a few hundred years depending on the exact points you used to calculate slope.
