Nitrous oxide its concentration has increased 15% since 1750, control of nitrous oxide is considered part of efforts to curb greenhouse gas emissions. A 2008 study by Nobel Laureate Paul Crutzen suggests that the amount of nitrous oxide release attributable to agricultural nitrate fertilizers has been seriously underestimated, most of which presumably, would come under soil and oceanic release in the Environmental Protection Agency data. Nitrous oxide also has been implicated in thinning of the ozone layer. A new study suggests that emission currently is the single most important ozone-depleting substance (ODS) emission and is expected to remain the largest throughout the
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