Accerlerating the introduction of green, environmentally friendly energy such as solar, wind and wave power is one of the most pressing issues facing humanity in the new millennium, the head of the United Nations Environment Programme told high-level meeting on renewable energy here. Speaking at a meeting of the G-8 Task Force on Renewable Energy, the UNEP Executive Director, Mr Klaus Toepfer, said green energy must be put at the heart of sustainable development if the threats of climate change and the need to tackle poverty and ill health in the developing world are to be truly addressed, according to a UN press release.