This article is based on assumptions of global and local ecosystem health. Quantifying ecosystem health is fascinating, important and very difficult. Etymologically, health is based on wholeness. In classical Greek philosophy, health is harmony, which can be defined as integrated diversity. Can we therefore measure the diversity and integrity of ecosystems? Bio-Diversity measures in ecosystems seem easy, but are actually quite complicated (two species of pine the same as pine and oak, or pine and rare moss?) — and measures of ecosystem integrity are even harder. But not hard as in impossible, hard as in more scientists should be working on it. Here's one recent paper.

Vieweger, A., & Döring, T. F. (2015). Assessing health in agriculture–towards a common research framework for soils, plants, animals, humans and ecosystems. Journal of the Science of Food and Agriculture, 95(3), 438-446.