It seems New York City has counters for everything these days. The famous debt clock, and now, a new 'carbon clock' was resurrected this past Thursday near Madison Square Garden and Penn Station. It counts the total amount of greenhouse gases that are trapped inside the Earth's atmosphere.
According to Scientific American, the counter takes into account all greenhouse gases, including carbon dioxide, methane, and nitrous oxide, and reports them in carbon dioxide equivalents. It skips the effects of natural cycles, such as the El Niño, and doesn’t factor in aerosols, which are difficult to measure and also exert a cooling effect.
This article appears in Jun 17-23, 2009.