the sphere of human consciousness and mental activity especially in regard to its influence on the biosphere and in relation to evolution

At the root of the primary definition of noosphere is a dual perception: that life on Earth is a unity constituting a whole system known as the biosphere; and that the mind or consciousness of life – the Earth’s thinking layer – constitutes a unity that is discontinuous but coextensive with the entire system of life on Earth, inclusive of its inorganic support systems. A third critical premise arising from the first two is that the noosphere defines the inevitable next stage of terrestrial evolution, which will subsume and transform the biosphere.

via:

http://www.merriam-webster.com/dictionary/noosphere

http://www.lawoftime.org/noosphere/theoryandhistory.html