Some waste is biodegradable, which means that it decomposes easily in the environment. Other waste does so much less quickly. Bear in mind that a tissue dropped in nature takes 3 months to decompose, a piece of paper takes 4 months, and chewing gum takes 5 years. An aluminium can decompose over 10 years, a plastic bottle takes at least 100 years, and a glass bottle requires several centuries.
No matter how quickly you think it will decompose, do not leave waste behind. Always take it with you and find a garbage can, or better yet, a recycling bin.
-Abrams, “365 Ways To Save The Earth”, 2008