By Celsias Team
Posted on Oct. 28, 2010. Listed in:
If you just so happen to have hundreds of thousands of dollars spare that you thought you might like to spend on a bit of space travel, the price of your ticket might not be the only high cost. A study has found soot emitted by rockets—not their carbon dioxide emissions—has the greater potential to contribute to global climate change in coming decades.
The researchers assume that a fast-growing suborbital space tourism market will develop over the next decade and examine the climate impact of soot and carbon dioxide emissions from 1,000 suborbital rocket flights per year, the approximate number advertised in recent materials promoting space tourism.
The study provides the first detailed look at how rockets using hydrocarbon fuel might affect Earth’s climate system. The researchers found that soot particles emitted by the proposed fleet of space tourism rockets would accumulate in a stratospheric layer at about 40 kilometers altitude—three times the typical altitude of airline traffic. These particles efficiently absorb sunlight that would otherwise reach the earth’s surface, causing projected changes in the circulation of the earth’s atmosphere from pole to pole. Unlike soot from coal power plants or even jet aircraft, which falls out of the atmosphere in days or weeks, particles injected by rockets into the stratosphere remain in the atmosphere for years.
“Rockets are the only direct source of human-produced compounds above about 22.5 kilometers and so it is important to understand how their exhaust affects the atmosphere,” says the study’s chief author, Martin Ross, of The Aerospace Corporation in El Segundo, California. He and his colleagues describe their findings in a scientific paper called Potential Climate Impact of Black Carbon Emitted by Rockets, to be published in Geophysical Research Letters, a journal of the American Geophysical Union.
The study, which used a sophisticated computer model of the earth’s atmosphere, finds that beneath the thin stratospheric layer of rocket soot, the earth’s surface could cool by as much as 0.7 degrees C, while Antarctica could warm by 0.8 degrees C.
“The response of the climate system to a relatively small input of black carbon is surprising,” says Michael Mills of the National Center for Atmospheric Research in Boulder, Colorado, a study coauthor, “and our results show particular climate system sensitivity to the type of particles that rockets emit.”
Image: Flickr - makelessnoise
