 Pernick and Wilder explain that , in the 1970s , clean technology was considered “ alternative , ” the province of back @-@ to @-@ the @-@ land lifestyle advocates , <unk> environmentalists , and lab scientists on research grants . Such technology was in an early stage of development , was too expensive , it did not have widespread political support , and very few large , established companies were embracing the sector . Even at the start of the 21st century , the term clean tech was not yet in the financial or business community ’ s vocabulary . But now , throughout much of the world , in trends large and small , there is " the beginning of a revolution that is changing the places where we live and work , the products we manufacture and purchase , and the development plans of cities , regional governments , and nations around the globe . " 
