Those of you living in New York City or visiting the Big Apple may be interested in the Deutsche Bank/MIT real-time carbon counter clock, a 70-feet tall digital display outside Madison Square Garden and Penn Station. At the unveiling yesterday the clock showed 3.64 trillion tonnes of "long lived" greenhouse gasses in the atmosphere, and rising by 800 million metric tonnes a second. If you like this display, you can put it on your (or client) computer desktop through a free widget.

It seems like a pretty cool idea, and obviously calls to mind the National Debt Clock, a less-impressive but nonetheless landmark feature also in New York City. However, I wonder if most viewers will be able to understand, let alone relate to, the 3.64 trillion number. I can understand "national debt" and "your family's share," but long-lived greenhouse gasses that increase by 800 million metric tonnes a second? I hear crickets, and they're not outside my office window.