Trace gas Trace gas The most abundant gases in the atmosphere are nitrogen (78.1%), oxygen (20.9%), and argon (0.934%). Combined, oxygen, argon, and nitrogen make up 99.934% of the gases in the atmosphere (not including water vapor). The other gases that are not part of the 99.934% of the atmosphere are called trace gases. The abundance of a trace gas can range from a few parts per trillion (ppt) by volume to several hundred parts per million by volume (ppmv). When a trace gas is added into the atmosphere, that process is called a "source". There are two possible types of sources
Shale gas in the United States infrastructure emerged as environmental concerns for the rush. In Pennsylvania, controversy has surrounded the practice of releasing wastewater from "fracking" into rivers which serve as consumption reserves. Methane release contributing to global warming is a concern. The word “fracking”, slang for hydraulic fracturing, has entered the English language. The Great Shale Gas Rush refers to the growth in unconventional shale gas extraction in the early 21st-century. Pennsylvania was featured in the Academy Award-nominated, environmental documentary Gasland by Josh Fox in 2010. Most of the filming for the 2012 Gus Van Sant dramatic film, Promised Land, starring Matt Damon, took place