Summary of Different Types of Variability

To fully understand climate as a dynamic system, scientists want to understand the factors that drive both large- and small-scale variability.

A graph measuring the ratio of oxygen isotopes from 5 to 0 and temperature in degrees Celsius from 0 to 12 overlayed on the x-axis. Age in millions of years ago from 0 to 70 on the y-axis. The data show negative temperatures at 0 m-y-a, 1 degree at 10 m-y-a, 5 degrees at 15 m-y-a, 4 degrees at 20 m-y-a, 5 degrees at 25 m-y-a, 1 degree at 30 m-y-a, 6 degrees at 40 m-y-a, 12 degrees at 50 m-y-a, 8 degrees at 60 m-y-a, 9 degrees at 65 m-y-a, 8 degrees at 70 m-y-a.
A decrease of CO2 in the atmosphere drove the change from the warm climate of the Eocene period to the relatively cold climate of today.
Graph of benthic oxygen isotope ratios ranging from 3.0 to 5.0 over the last million years. A double-sided arrow on the right indicates that lower numbers are warmer and higher numbers are colder. The data show a cyclical pattern over tens of thousands of years from troughs indicating ice ages to peaks indicating interglacials.
Small changes in Earth’s orbit around the sun account for the waxing and waning of ice ages over the past million years.