-Introducing our Planet-
(pages 16-17)

Introducing our Planet (pages 16-17)

 

Three Principles

We began investigating the Earth system by asking the first system question: What are the parts of the Earth system? Our answer focused on three parts - Earth's matter, Earth's energy and Earth's life. The second system question is - how does the system function as a whole?

Guess what? We have already answered that question. When we looked at each part of the Earth system, we learned how that part works for the planet as a whole. As a result, we can say that there are three simple principles that work together:

MATTER CYCLES
Each of the elements that is vital for life exists on Earth in a closed loop of cyclical changes. From a systems point of view, Earth is essentially a closed system with respect to matter.

ENERGY FLOWS
The functioning of our planet relies on a constant input of energy from the sun. This energy leaves Earth in the form of heat flowing to outer space. From a systems point of view, Earth is an open system with respect to energy.

LIFE WEBS
A vast and intricate network of relationships connects all Earth's organisms with each other and with the cycles of matter and the flows of energy. From a systems point of view, Earth is a networked system with respect to life.

These three principles can help us understand essentially all environmental issues. When we confront an environmental issue, we should first explore the roles of matter, energy and living organisms. Where does the matter (carbon, water, pollutant) come from and where does it go? Does the issue involve changes to our planet's energy flows? How do plants, animals and microorganisms influence the issue and how are they affected by it? As a result of answering these kinds of questions, we will discover that the three guiding principles provide an organizing framework that makes common sense out of complicated issues.

Book Overview
In the 21st century, we find ourselves in a new world. Without meaning to, we can change the way that our planet works. At the same time, we are developing a much deeper understanding of the Earth system.

This chapter has introduced three principles that can help us focus on major concepts rather than become lost in confusing details. The next three chapters will help us understand each of these three principles much more deeply. You will know and be able to explain how Earth works in terms of cycles of matter, flows of energy and the web of life.

 

Earth is a recycling planet powered by the flow of solar energy that supports a networked web of life.

 

But merely knowing something, even something as important as how our planet works, is not enough. We need to apply that information in our lives. The last two chapters apply this understanding of the whole Earth system to environmental issues that we face globally and locally. The three Earth systems principles help us understand these issues, and they also provide guidance regarding what we need to do as a global species, nations, local communities and as individuals.
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