Dear Pablo,

With the 4th of July around the corner, I was wondering: Do fireworks give off greenhouse gases?

I too have always wondered if fireworks are a fitting way to celebrate the new year when the global climate is high on our list of concerns. Let’s find out.

Julie Heckman, executive director of the American Pyrotechnics Association, estimates that 18,000 fireworks shows occur across the nation on July 4 alone. According to the National Council on FireworksSafety, the United States consumed about 272.1 million pounds of fireworks in 2006, of which only about 9.5 percent are commercial fireworks shows. The remaining “consumer fireworks” are sold in roadside shacks and used to celebrate events and perform Darwin’s work.

Fireworks are propelled by black powder (aka gunpowder). This substance consists of an oxidizer (potassium nitrate), a fuel (carbon), and an accelerant (sulfur). For every 270 grams of black powder used, 132 grams of carbon dioxide are created, the rest of it turning into potassium sulfide and nitrogen. Unlike gasoline, black powder already contains an oxidizer so that the combustion results in less CO2 created than the starting weight of the substance. Gasoline releases roughly 20 pounds of CO2 per gallon when combusted because it combines the carbon in the fuel with oxygen from the atmosphere.

The standard unit for measuring greenhouse gas emissions is metric tons, so I will convert the 2006 volume of fireworks consumed in the U.S.: 123,422.5 metric tons. Since 270 grams of black powder create 132 grams of carbon dioxide, we can multiply that ratio (132/270 = 0.4889) by the volume of fireworks to get annual U.S. emissions from fireworks: 60,340 tons. This is more than 12,000 cars emit in a year, or the emissions from 115,000 light bulbs left burning for a year!