... up of carbon dioxide, and water vapour was the second most abundant gas. (britannica.com)
We now have abundant gas at reasonable prices, and it's also holding down electricity costs. (energytrendsinsider.com)
Carbon monoxide has a vapour pressure intermediate between that of nitrogen and methane, so Owen and his colleagues believe that carbon monoxide is the second most abundant gas in Pluto's atmosphere. (newscientist.com)