I'm surprised environmentalists don't campaign to reduce standard margin sizes. A standard piece of 8.5x11 paper has an area of 93.5 square inches. With 1-inch top and bottom margins and 0.75-inch side margins, 30.5 square inches are wasted on each page -- almost one-third of the surface area! Reducing all margins to 0.5 inches would cut margin wastage to one-fifth of a page, reducing paper usage by almost 13%! Less garbage to haul, fewer trees to chop down, reduced burden on recycling and disposal land use, and billions of dollars saved -- everyone wins.
For comparison, look at how much could be saved just from just from two-sided copying.
Photocopying accounts for more than one quarter of all office paper use. In 1990, 1.9 million tons of paper was used in photocopiers in the United States. By increasing two-sided copying to the extent feasible, offices in the United States could save 373,000 tons or about 20 percent of paper used annually. Doing so would result in cost savings (in paper purchase and waste disposal) of $414 million (Source: R.Graff & B. Fishbein, Reducing Office Paper Waste, INFORM (1991)). Additional savings can be realized in reduced filing space required and reduced mailing costs associated with two-sided copying of documents.
That was 15 years ago so I'm sure these numbers have gone up, even with the emergence of computing technology. Reducing margin sizes would save money on the original documents, and also on every single copy made!