The Group of Eight environment ministers will open on Saturday a three-day meeting in Kobe on ways to meet Japan's proposal to halve global greenhouse gas emissions by 2050. The ministers will seek G8 cooperation on promoting the "co-benefits approach" to help developing countries achieve economic growth while curbing pollution and waste, Environment Ministry officials said. The ministers will also discuss steps to protect biodiversity and to ensure the efficient use of resources with the "3Rs" approach of reducing waste by promoting reuse and recycling, the officials said.