The Clinton administration is proposing that carbon dioxide absorbed by forest and agricultural lands could account for a substantial amount of the greenhouse gas reductions required under a pending international treaty on global warming. Such credits could ease the burden on industry to cut emissions of heat-trapping carbon dioxide from the burning of fossil fuels. They also could make the treaty more acceptable to the Senate, which must ratify it. The State Department, in a report to the United Nations, calculated that about 310 million metric tons of carbon dioxide are absorbed annually in US forests and in soil used for crops and livestock grazing. This carbon sink amounts to nearly half of the annual carbon emission reductions the United States would be expected to make beginning in the year 2008 under the treaty.