Ecological principles represent the very core of Environmental Science in general, and this is why chapters 5-7 are so important for our work. The main reason is that all of nature, all of life itself as it exists on Earth can only work on some conditions which cannot be compromised. Human history represents a chain of examples on how ignoring these natural principles can harm us via disrupting natural processes and shifting the balance of things. Please pay attention: it does not matter what we think about the comparative importance of different processes in nature, because many of them can only work in a particular order, and this order cannot be changed. Our attempts to interfere can cause problems, regional and global ecological crises, and jeopardize our existence.