We give you a simplified explanation of the main features of our system.
The biosphere, our home
The only place – as far as we know now- where our way of life is possible. Playing, breathing, eating, dancing, meeting, enjoying, everything takes place in our biosphere. A layer that thin that you could compare it to the skin of an onion.
The biosphere works like a glass cap over the earth.
Energy can go in- and out The biosphere is open to sunlight (energy) and reflects energy back in the form of heat radiation. So, for example, it can get warmer under the cap if the energy is not fully reflected back.
But it is a closed system to matter Except for a single meteorite or some dust that comes in, or a satellite that we launch and shoot out into space, all the matter that was there 4.5 billion years ago is still here today. It just changes shape but it remains under the cap.
The Earth’s crust itself is also a closed system Deep inside the earth’s crust fossil fuels, minerals and (heavy) metals have been stored for millions of years. Apart from volcanic eruptions or erosion, these substances do not just end up in the biosphere.
Everything on Earth works in cycles
The fact that we have such a beautiful world around us is because everything runs in circles. All life on Earth adheres to the laws of thermodynamics.
All energy stays, it just changes shape The First Law of Thermodynamics says that all energy is preserved; nothing disappears, the form just changes. (eg heat turns into movement).
All matter breaks down and spreads throughout the system The second law of the Conservation of Matter states (among other things) that all matter continues to disintegrate into smaller and smaller particles and to spread over time. We call this ‘entropy’.
Below you can see how it works with plastic.
We live thanks to photosynthesis
So everything always falls apart into smaller and smaller particles. The reason we are not sitting on a mountain of dust, but have a beautiful, lavish world around us, is due to plants and the process of photosynthesis. Plants grab those small particles and with the help of water and sunlight they make oxygen and new building blocks for our lives.
Fast and slow cycles
You may have heard that we should stop burning fossil fuels because there is too much carbon in our biosphere. Carbon (CO2) is like oxygen for plants, so what is the problem? We explain this on the basis of the different carbon circles on our planet. We have a fast carbon cycle and a slow carbon cycle.
Fast carbon cycle
Plants make oxygen and glucose, humans and animals eat plants, breathe in oxygen and excrete CO2 and manure. Plants use this for photosynthesis. This is a beautifully balanced cycle. We call this the fast carbon cycle. You breathe every minute and eat every day.
Slow carbon cycle
The Earth’s crust also forms a closed system. Here we are dealing with a very slow carbon cycle. A single volcanic eruption or weathering causes stored CO2, minerals and metals to enter the biosphere, and through mineralization and sedimentation, it returns to the Earth’s crust. This cycle is also perfectly balanced, but takes hundreds to millions of years. Fossil fuels have been built up over millions of years and lie deep underground.