As leaders of the Group of Eight (G-8) industrialized nations meet for three days in Okinawa, Japan, environmentalists are hoping to focus attention on green issues. Activists are calling on the nations — in particular, Canada, Japan, and the U.S. — to end logging subsidies that destroy forests and waste government money. A report released yesterday by the World Resources Institute and Greenpeace found that G-8 governments spend more than $3 billion a year to subsidize logging operations.