In burials all over the U.S. we use so many different chemicals for embalming and such processes, trees (for the coffin), and tons upon tons of concrete for tombs and vaults. A green burial reduces the impact a normal burial would have of the environment. People have invented biodegradable coffins and as for the embalming fluid and concrete, you don't need them! Cemeteries take up valuable room for trees and other flourishing plants, but with a green burial, you don't need them. It's just you, organisms that decompose your tissues, and pure natural process. This is just another creative way to help out the environment.
Information From: http://www.greenburials.org/FAQ.htm#What_are_the_benefits_of_a_green_cemetery_over_a_traditional_cemetery