# Do the fluctuations change?

The next interesting question is, do the fluctuations in CO2 change over time? Keeling couldn't answer that in his first paper in 1960, because he only had 3 years worth of data. But 50+ years later, we can definitely provide some answers.

### Are the yearly fluctuations constant across time?

• I need a hint ... :
Measure the height of the yearly peak in two places -- towards the beginning and towards the end of the dataset. Rollover the graph for help...

### Is the year-to-year increase consistent across time?

• I need a hint ... :
You could measure the increase again, but let's do something simpler -- just connect the peaks every ten years and look at the slopes of the lines. Rollover the graph to see this one, because it's not easy to visualize.

#### I think I have the answer: The year-to-year increase is speeding up – the slope of the line is increasing.

Currently CO2 is increasing by about 2.5 ppm per year -- over 6 times faster than when Keeling first started his measurements.