Carbon-dioxide concentration and gas age from the Vostok Ice Cores to 414,000 years before present. More detailed data is available from the web page. Part of the Ice Core...

The Rutgers Snow Extent Climate Data Record gives a time series of snow cover the Northern Hemisphere. Also broken down into major landmasses. It's a product of Rutgers...

About About page states: The Carbon Dioxide Information Analysis Center (Thomas A. Boden, Director), which includes the World Data Center for Atmospheric Trace Gases, has...