Sustainability is a utopian vision that requires living harmoniously with nature, which will exact harsh penalties on species that exceed Earth's carrying capacity and violate nature's laws. To make this vision a reality, humankind needs a global ethical consensus on sustainable use of the planet - sustainability ethics. Sustainability ethics has the goal of developing a sustainable, mutualistic relationship between humankind and the interdependent web of life that serves as Earth's ecological life support system. The quest for sustainable use of the planet is a value judgment that has more than one component. Arguably, the most important is increased attention to and compassion for posterity's quality of life, in short, leaving a habitable planet for future generations. This requires leaving natural capital and the ecosystem serves it provides undiminished at the least and increased at best. Although material possessions can be left to direct descendants, protecting the planet's ecological life support system must not only be for all of humankind's descendants but those of the 30+ million other species with which we share the planet. This is difficult because the recipients are distance (as individuals) both temporally and spatially. Therefore, this quest will not be realised until an agreement emerges on the values and attitudes necessary to make sustainbility a reality. Science can then develop the standards and criteria necessary to reach this goal. In view of present unsustainable practices, a basis ethical consensus is necessary to develop sustainable practices.