To understand climate fluctuations, it is helpful to know the amount of time over which these changes have occurred.

Question: On average, how many years did it take for historical surface temperatures to change by one degree?

The Climate Trends learning tool has a slope tool that allows you to measure the rate of change between data points. Open the temperature data in the learning tool and click on the Calculate Slope tab and select Temperature. Roll your mouse over the graph. Click on a peak to begin calculating slope, and then click at the bottom of the peak. The slope between these two points will be displayed at the top left of the graph.

Between approximately 138,000 and 126,000 years before present, there is an increase in temperature. If you use the slope tool to measure the rate of temperature change for this period, you will get approximately 0.001°C per year.

At this rate, it would have taken approximately 1000 years for the surface temperature to increase by only 1°C!

Question: What are some natural events that contributed to historical changes in our climate?