Methane is a potent greenhouse gas that contributes to global warming and climate change. It is produced when organic waste decomposes anaerobically (without oxygen) in landfills1. Construction and demolition waste, which accounts for about a third of all solid waste generated in the world2, often contains a large amount of organic materials, such as wood, paper, and food waste1. Therefore, disposal of solid waste from building construction and operations in landfills has a substantial effect on methane emissions13. Incineration of solid waste also produces greenhouse gases, such as carbon dioxide, carbon monoxide, and hydrochloric acid, but at lower levels than landfilling45. Volatile organic compounds (VOCs) are not greenhouse gases, but they can react with other pollutants to form ozone, which is a greenhouse gas and a health hazard4.

Strategically locating functional and decorative hardscape on a project site can reduce the amount of on-site impervious area. Impervious surfaces are surfaces that do not allow water to infiltrate into the ground (e.g., concrete or asphalt). By reducing these surfaces, we can increase water infiltration, which helps recharge groundwater supplies and reduces stormwater runoff that can lead to erosion and water pollution. References:
LEED Green Associate Candidate Handbook, U.S. Green Building Council resources