Japan is ready to step to the plate at the upcoming G-7 meeting in Denver as the environment's cleanup hitter. Then again, it might not even take its bat off its shoulder.

Japanese officials are becoming increasingly aware that they may make little headway on environmental matters during the June 20 to 22 meeting of leaders from the major industrialized economies -- the U.S., Canada, Britain, Germany, France, Italy and Japan -- and Russia. Although a document to be issued at the Denver summit will call for "reductions" of greenhouse gases -- primary culprits of global warming -- it may not contain the word "limitations," which Tokyo currently is pushing for.

In addition, it is a possibility that the document will make no mention of the need for strengthened international cooperation in fighting serious maritime oil spills, as has been demanded by Japan in the wake of the January Nakhodka accident that fouled the Sea of Japan. The environment will be high on the agenda at the Denver summit, which will be immediately followed by a special session in New York of the United Nations General Assembly to review progress made on environmental protection since the Earth Summit in Rio de Janeiro in June 1992.