Environment-related problems are extremely important for mankind, the fate of humanity itself depends on our ability to solve these problems. These problems are complex, we cannot solve them without using powerful computers. Thus, in the environmental research, environment-related computing is one of the main computing-related research directions. Another direction is related to the fact that computing itself can be (and currently is) harmful for the environment. How to make computing more environment-friendly, how to move towards green computing -- this is the second important direction. A third direction is motivated by the very complexity of environmental systems: it is difficult to predict how environment will change. This seemingly negative difficulty can be reformulated in more positive terms: that by observing environmental processes, we can find values which are difficult to compute. A similar observation about quantum processes has led to successful quantum computing, so why not use environmental processes themselves to help us compute? This is the third direction in environment-related computing research. In this paper, we provide three examples that show that in all three directions, non-trivial mathematical analysis can help.