The U.S. Green Building Council (USGBC) administers the LEED rating systems development. The LEED rating systems are frameworks that provide guidance and criteria for designing, constructing, operating, and maintaining green buildings. The USGBC is responsible for developing, maintaining, and updating the LEED rating systems through a consensus-based process that involves various stakeholders, such as technical experts, industry leaders, government representatives, and public comments. The LEED Green Associate Candidate Handbook states that "USGBC is committed to transforming the way our buildings are designed, constructed and operated through LEED" [1, p. 7]. Reference: LEED Green Associate Candidate Handbook, [LEED Rating Systems | U.S. Green Building Council]

According to systems thinking, climate change is an example of a positive feedback loop, which means that an initial change in one part of the system causes a chain ofevents that amplify the effects of the change. For example, as the Earth warms due to increased greenhouse gas emissions, ice sheets and glaciers melt, reducing the albedo (reflectivity) of the Earth's surface and allowing more solar radiation to be absorbed, which further increases the temperature and accelerates the melting process. This is one of several positive feedback loops that can accelerate climate change and make it harder to reverse.
15 Climate Feedback Loops and Examples - Earth How
Systems Thinking Through Climate Change - 5 Positive Feedback Loops
What are climate change feedback loops? - The Guardian

Explanation
Water Efficiency is the only credit category that does not have a prerequisite in LEED v4 for Building Design and Construction. Prerequisites are the minimum requirements that all projects must meet to be eligible for LEED certification. They are mandatory and non-weighted, meaning they do not contribute to the project's score. The other credit categories have at least one prerequisite each, as shown in the table below:

References: LEED v4 Reference Guide for Building Design and Construction, p. 17 1; [LEED v4 BD+C Scorecard]

Explanation
Installing concrete sidewalks and parking areas will increase the quantity of the rainwater that is discharged from a site. Rainwater is the water that falls as precipitation on a site. Rainwater discharge is the amount of rainwater that leaves a site as surface runoff or subsurface flow. Rainwater discharge can affect the quantity and quality of water resources downstream by causing erosion, flooding, sedimentation, pollution, and habitat loss. Concrete sidewalks and parking areas are examples of impervious surfaces that prevent rainwater from infiltrating into the soil and increase rainwater discharge by creating more runoff1 . References: LEED v4 Green Associate Candidate Handbook1, EPA's Stormwater Management

Utilizing recycled materials achieves the green building objective of minimizing the need for landfills. Recycled materials are materials that have been recovered or diverted from the waste stream and processed into new products or materials. Utilizing recycled materials can reduce the amount of waste that is sent to landfills or incinerators, which can have negative impacts on the environment, such as occupying valuable land, contaminating soil and water, and emitting harmful gases. Utilizing recycled materials can also save natural resources, reduce greenhouse gas emissions, create jobs, and lower disposal costs12. Reference: LEED v4 Green Associate Candidate Handbook1, EPA's Recycling Basics2