J. Stan Rowe died this year and he left many significant contributions to ecology and environmental ethics. His Earth Manifesto includes the following principles which provide a good a simple guide to the big picture as I've come across:
CORE PRINCIPLES
Principle 01 The Ecosphere is the Center of Value for Humanity
Principle 02 The Creativity and Productivity of Earth’s Ecosystems Depend on their Integrity Principle 03 The Earth-centered Worldview is supported by Natural History
Principle 04 Ecocentric Ethics are Grounded in Awareness of our Place in Nature
Principle 05 An Ecocentric Worldview Values Diversity of Ecosystems and Cultures
Principle 06 Ecocentric Ethics Support Social Justice
ACTION PRINCIPLES
Principle 07 Defend and Preserve Earth’s Creative Potential
Principle 08 Reduce Human Population Size
Principle 09 Reduce Human Consumption of Earth Parts
Principle 10 Promote Ecocentric Governance
Principle 11 Spread the Message