About the ENDS Carbon Counter
The ENDS Carbon Counter displays the estimated long-term trend for carbon dioxide in the Earth's atmosphere, updated in real time.
The Carbon Counter is based on data from the US National Oceanic and Atmospheric Administration (NOAA) website "trends in carbon dioxide", and specifically on NOAA's global monthly average trend data. This draws together measurements from a global network of sampling sites and smooths the pronounced seasonal rise and fall in atmospheric CO2 to produce a trend line.
The Carbon Counter projects NOAA's trend data forward by calculating the rate of change from a line of best fit over the previous 12 months of measured data.
CO2 concentration is expressed in parts per billion. This is the number of molecules of CO2 as a fraction of the total number of molecules in air after water vapour has been removed.
Latest update: 28/09/09. The Carbon Counter is now based on published NOAA data up to July 2009. The current estimated rate of increase in CO2 is 1,336 parts per billion per year.
