The biggest challenge facing humans globally is climate change, which is severely impacting glaciers and deserts, two of the most fragile ecosystems. Though the desert environment is harsh and hostile, and the rainfall scanty and unreliable, the denizens of it are living comfortably due to the traditional knowledge they have gained over the years. Their skills and practices of traditional knowledge, such as dryland agriculture, water conservation, livestock rearing, and indigenous knowledge for survival and conservation of nature and natural resources, have helped them in their survival. Because of their attitude towards all life forms, the flora and fauna are flourishing well in the region. The present communication is about the origin of the Thar, its physiography, natural resources, traditional knowledge, its zoo-geographic importance, wildlife conservation, water management, vegetation, fauna, and other resource that abound the Thar. It also deals with the threats this tenuous ecosystem is facing in terms of mining natural resources, oil exploration and setting of the refinery, vast network of wind mills and its supply chain, setting up of solar power plants, ecological implications of Indira Gandhi Canal water, and changing attitude of its inhabitants. All these threats are making this desert, which is eighteenth largest desert of the world, more susceptible to ecological catastrophe. Measures to promote sustainable development in this highly populated desert are also suggested. If we don’t get serious about conservation of this only desert ecosystem of India, we will lose it very soon.