Climate Change and The Data

Global Thumbnail Data

Atmospheric carbon dioxide measurements calculated from ice cores indicates steadily rising concentrations from the 1880s through the mid 1950s. Instrument measurements since the 1950s show a sharply continuing rise. About 290 parts per million (ppm) atmospheric CO2 was believed present in 1880; about 397 ppm is currently recorded (January, 2014).

Approximately 5.5 to 8 billion metric tons of carbon dioxide is released annually into the atmosphere through the burning of fossil fuels (coal, oil, natural gas). Conservatively, an additional 1.6 billion tons is released from land uses, such as agricultural tillage and clearing of tropical and boreal forests. Oceans may take up approximately 2 billion tons a year. Perhaps another 2 billion tons are taken up by identified and unidentified terrestrial carbon-storing sources such as forests and soils. The remaining of 3 to 4 billion tons of CO2 per year is added to existing concentrations already present in the atmosphere.

During the past century, global surface temperatures have increased at a rate near 0.11°F per decade. But this trend has increased to a rate approximately 0.32°F per decade over the past 25 to 30 years. There have been two sustained periods of warming, one beginning around 1910 and ending around 1945, and the most recent beginning about 1976.

The ten hottest years in the modern period of instrumental data have all occurred since 1989. The warmest year was 1998, followed by 2002 and 2003 (tied), 2001, 1997, 1995, 1990 and 1999 (tied) and 1991 and 2000 (tied). More recent data indicates the year 2012 may rank among the ten hottest, coming in about eighth or ninth.

For more information about climatology data with links for all interest levels, visit the RealClimate site. NASA also operates a global climate change site as does Oak Ridge National Laboratories. For information about data pertinent to the United States, visit the Environmental Protection Agency’s site.