Thanks to conservation efforts and the rise of e-books, the publishing industry is creating a leaner and cleaner paper trail.

According to a new report by two environmental groups - the Book Industry Environmental Council and Green Press Initiative - paper suppliers use around 25 percent recycled fiber for book materials, compared with an estimated 5 percent in 2004.

Industry greenhouse gas emissions have dropped from around 12 million metric tons to 9 million between 2006 and 2010. And paper usage overall fell from 1.6 million tons in 2006 to just over 1 million in 2011, requiring some 5 million fewer trees.

Todd Pollak, the Green Press Initiative's program manager, said Thursday that slow economic times may also have reduced paper consumption.