About the Data
The 2009 State of the Climate report served as a basis for the poster and this website. This report draws on data for 10 key climate indicators that all point to the same finding: the scientific evidence that our world is warming is unmistakable. More than 300 scientists from 160 research groups in 48 countries contributed to the report, which confirms that the past decade was the warmest on record and that the Earth has been growing warmer over the last 50 years.
This set of indicators was selected, as we would unambiguously expect them to increase or decrease if the world were warming. In a warming world, based upon simple physical principles we would expect some indicators to increase land surface air temperature, sea-surface temperature, marine air temperature, sea level, tropospheric temperature, ocean heat content and specific humidity.
Conversely, we would expect the following indicators to decline: snow cover, sea-ice extent, glacier mass, and stratospheric temperatures. Stratospheric temperature decline is also influenced by ozone depletion.
Click here for a 10 page summary or full supplemental package.
How do we know the world has warmed? by J. J. Kennedy, P. W. Thorne,
T. C. Peterson, R. A. Ruedy, P. A. Stott, D. E. Parker, S. A. Good, H. A. Titchner, and K. M. Willett, 2010: [in "State of the Climate in 2009"]. Bull. Amer. Meteor. Soc., 91 (7), S79-106.
Global Climate Change Impacts in the United States, U.S. Global Change Research Program. Thomas R. Karl, Jerry M. Melillo, and Thomas C. Peterson, (eds.). Cambridge University Press, 2009.
Climate Literacy: The Essential Principles of Climate Sciences, U.S. Global Change Research Program/Climate Change Science Program. (2009). Washington, DC