Project Learning Tree is an award-winning environmental education program designed for teachers and other educators, parents, and community leaders working with youth from preschool through grade 12.

PLT's GreenSchools program inspires students to improve the environment at their school, at home, and in their community. Student-led Green Teams apply STEM (science, technology, engineering, math) to create greener and healthier schools—and save schools money!

Five hands-on, student-driven investigations are at the heart of PLT's GreenSchools program. 

1. Energy Investigation - Students investigate how much energy their school uses, the main sources of that energy, and ways to implement energy-saving strategies.
2. Environmental Quality Investigation - Students investigate areas where improvements can be made in indoor air quality, transportation, chemical use, and more.
3. School Site Investigation - Students investigate natural habitats, wildlife, trees, grounds maintenance practices, and ways to make improvements to their school site.
4. Waste & Recycling Investigation - Students investigate how much waste their school generates and where it goes, as well as recycling and composting efforts.
5. Water Investigation - Students investigate the source, cost, and quality of their school's water supply, and ways to enhance current water conservation practices

Each investigation details specific things for students to measure and observe, along with student worksheets to fill out and guidance on how to combine data collected into a school-wide analysis.

This printed guide includes all five of PLT's GreenSchools Investigations plus an Adult Leaders section with tips on how to form a Green Team, suggestions for how students might conduct the Investigations, and ways to obtain grants for action projects.

It also provides information on the importance of greening schools to make them healthier places for students and teachers to learn and work, and specific examples of how the GreenSchools Investigations support STEM education.