October 1985

Document Type


Degree Name



Dept. of Environmental Science


Oregon Graduate Center


An investigation of methane increase during the period 1965-81 is presented. A critical review of the literature has been carried out to isolate background methane measurements. A seasonal and global correction procedure has been applied to these selected GC measurements of different researchers. The corrected data have been analyzed to quantify the trend of methane. The results show an annual methane rise of about 1%. A survey of continuous, systematic measurements of methane made in the 80s indicates a similar result. Polar ice core measurements of methane, both from arctic and antarctic, have been examined to determine the period during which the recent rapid rise has begun. The analyses demonstrate that methane increase started about 150 years ago. A doubling of atmospheric methane level during this period has now occurred. A review of IR spectroscopic data and Russian methane measurements has also been carried out. The Russian observations have large variabilities associated with them; the higher mean of these data indicate possible non background levels of methane. Analysis of CH4 sources and possible effects of increasing methane imply that a 20% depletion of hydroxyl radicals may already have occurred, while a large portion of the CH4 increase may have occurred because of increasing emissions from sources controlled by human activities.





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