Carbon dioxide surface, warming the surface and the lower atmosphere. Less energy reaches the upper atmosphere, which is therefore cooler because of this absorption. Increases in atmospheric concentrations of and other long-lived greenhouse gases such as methane, nitrous oxide and ozone have correspondingly strengthened their absorption and emission of infrared radiation, causing the rise in average global temperature since the mid-20th century. Carbon dioxide is of greatest concern because it exerts a larger overall warming influence than all of these other gases combined and because it has a long atmospheric lifetime (hundreds to thousands of years). Not only do increasing carbon dioxide
Industrial gas ambient temperature is low enough; this includes ethylene (R1150), carbon dioxide (R744), ethane (R170), nitrous oxide (R744A), and sulfur hexafluoride; however, these can only be liquefied under pressure if kept below their critical temperatures which are 9 °C for CH ; 31 °C for CO ; 32 °C for CH ; 36 °C for NO ; 45 °C for SF. All of these substances are also provided as a "Gas" (not a vapor) at the 200 bar pressure in a gas cylinder because that pressure is above their critical pressure. Other gases can only be supplied as liquid if also