The Earth is a closed system for matter

The Earth is made up of chemical elements – think of the periodic table. That is a list of all basic elemental materials on our planet. Because of gravity, matter (comprising all solids, liquids and gases) does not leave the system. It is a closed box. And, the laws of thermodynamics, long agreed by scientists, tell us that it’s impossible to destroy matter. So the chemical matter we have on Earth will always be here. The important question is, how are those chemicals organised?

The Earth is an open system for energy

It is accepted science that the Earth is an open system for energy. Energy radiates into the Earth’s system, mainly from the sun. Energy is then radiated back into space from the Earth, with the flows being regulated by the Earth’s atmosphere and ozone layer. This delicate balanced transfer of energy maintains the surface temperature at a level that is suited to the forms of life that have evolved and currently exist.

Discussion forum activity

1. Take a moment to think about what you understand of global warming and climate change. Consider these questions:
   • How does the above explanation of basic scientific principles fit with your understanding of global warming and climate change?
   • At a basic level, how might the climate system be affected if the concentration of gases making up the atmosphere and ozone layer are changed?
   • Is that system likely to remain unchanged?
2. Write your answers in the Discussion Forum. Look for the appropriate topic.