Common Sense Climate Index

The Common Sense Climate Index (Hansen et al. 1998) is a simple measure of the degree (if any) to which practical climate change is occurring.

This global animation shows the Climate Index averaged over the last five years of analyzed temperature data (2013-2017). The animation was created using a 0.5°×0.5° grid of station-only data with a 1200km smoothing radius.

The index is a composite of several everyday climate indicators. It is expected to have positive values when warming occurs and negative values for cooling. If the Index reaches and consistently maintains a value of 1 or more, the climate change should be noticeable to most people who have lived at that location for a few decades.


The original development of these CSCI webpages was discontinued in 1999. The idea was to use daily and monthly mean temperature and precipitation data to form a combined index, but at that time most displays were based on monthly mean temperatures. Only the New York City example also used some daily temperature records. No figures incorporating moisture data were shown. It became apparent that the index based on seasonal mean temperatures alone was not significantly different from the combined index. Currently, we are only updating the pages based on that simpler climate index, a quantity that can be computed for all stations with sufficient data in the 1951-1980 period.

The following two links are to the old New York City example and an explanation of the old CSCI scale.


  • Hansen, J., M. Sato, J. Glascoe, and R. Ruedy 1998. A common-sense climate index: Is climate changing noticeably?. Proc. Natl. Acad. Sci. 95, 4113-4120.
  • Karl, T.R., R.W. Knight, D.R. Easterling, and R.G. Quayle 1996. Indices of climate change for the United States. Bull. Amer. Meteor. Soc. 77, 279-292.
  • Peterson, T.C. and R.S. Vose 1997. An overview of the global historical climatology network temperature database. Bull. Amer. Meteor. Soc. 78, 2837-2849.


Please address questions about these CSCI webpages to Dr. Reto Ruedy.

This research was originally led by Dr. James E. Hansen, now retired. Dr. Makiko Sato and Jay Glascoe also participated in creating the Common Sense Climate Index.