IGBP has launched the Climate-Change Index at the United Nations climate negotiations in Copenhagen. The index combines annual changes of four directly-measured key parameters of global change: carbon dioxide, temperature, sea level and sea ice.

Watch a two-minute film of the IGBP Climate-Change Index on YouTube.

The index rises steadily from 1980 – the earliest date the index has been calculated. The index dips in just three years, 1982, 1992 and 1996 and looks effective at capturing major natural events that affect climate, and their knock-on effect on the planet. The dips coincide with major volcanic eruptions on Earth: Mount Pinatubo, El Chichon and Caribbean island of Montserrat.

If this link proves robust, the index is an excellent visual tool to show how external events can have rapid planetary-scale effects. The overall direction of change – a climbing cumulative index – highlights the extent human activities are having on the planet's climate system.

The index has been developed with input from a large number of scientists involved in global-change research. The index will be updated annually.