It would be silly, as James J. Kilpatrick suggested {op-ed, Nov. 13}, for Congress to spend $19 million for an esoteric study of livestock flatulence, unless, of course, livestock are suspected (as they are) of being one of the major sources of the greenhouse gas methane.

A study of the flatulence of cattle may sound absurd, but taxpayers could do worse. More than flatulence will be studied. Cattle emit methane through respiration and by belching. Less methane is produced by flatulence, but flatulence seems a more preposterous target than respiration.

Methane is no laughing matter. Of the trace gases now accumulating in the atmosphere, methane is second only to carbon dioxide in its contribution to the greenhouse effect. Emissions from cattle and other ruminants such as as sheep and goats may contribute a significant percentage of methane emissions. However, data are scant, and most estimates of the methane production of cattle are extrapolated from a few measurements made with sheep.

Kilpatrick cited an eminent scholar, M. A. K. Khalil, as questioning the importance of methane emissions by ruminants in greenhouse warming. Indeed, it will be difficult to control emissions in some of the world's cattle and certainly in wild ruminants. Nonetheless, an Environmental Protection Agency report on reducing methane emissions from livestock suggested ways in which livestock methane yields could be lowered through changing diets and additions to feeds. Whether such actions can significantly reduce the threat of global warming remains to be determined.

An increasing human population and income level in the world may aggravate the problem of atmospheric methane by increasing the demand for livestock and livestock products. This trend could lead to increased emissions. If uncertainties in methane gas emissions from livestock could be reduced and policies for control developed for $19 million, it would be money well spent. -- Kathleen M. Lemon -- Laura A. Katz The writers are members of the research staff of Resources for the Future.