[Crowd Noise] That's the sound of climate change negotiations—and CO2 being released. All this talking is a seemingly significant source of greenhouse gas emissions and not just because negotiators have traveled to Copenhagen from all corners of the globe.

Whether it be the jets of world leaders—or shutting down the city to proceed in motorcades—transportation contributes 25 percent of global emissions. Then there's the vital warm and cozy hotels to house us here in this wintry town. In fact, the government of Denmark estimates that this climate conference will produce in its two weeks the equivalent greenhouse gas emissions of more than 600,000 Ethiopians.

The bulk of that is the more than 46,000 metric tons of carbon dioxide that comes just from all the flights into and out of Copenhagen airport. But the Danes have a plan. They've sent enough cash to Bangladesh to replace 20 old, heavily polluting brick factories with more modern facilities, which will lead to an annual savings of some 100,000 metric tons of CO2.

Of course, the only thing that would really justify all this "hot air" is a global, binding, verifiable, equitable agreement to combat climate change. But achieving that is a lot harder than buying a new brick factory in Bangladesh.--David Biello, from Copenhagen