Sustainability is the capacity to endure in a relatively ongoing way across various domains of life. In the 21st century, it refers generally to the capacity for Earth's biosphere and human civilization to co-exist. Sustainability has also been described as "meeting the needs of the present generation without compromising the ability of future generations to meet their needs" (Brundtland, 1987). For many, sustainability is defined through the interconnected domains of environment, economy and society. Despite the increased popularity of the term "sustainability" and its usage, the possibility that human societies will achieve environmental sustainability has been, and continues to be, questioned—in light of environmental degradation, biodiversity loss, climate change, overconsumption, population growth and societies' pursuit of unlimited economic growth in a closed system.