What is going on with our world? Some environmental impacts, like climate change, seem so large and abstract, that it is often difficult to see what we, as individuals can do about them.
But, we change the world in many more ways, often locally and perhaps more preventable, if only we knew what is going on. With these drawings, I like to explain how we affect our immediate surroundings.
Years ago, I used to be teaching ecology, in the disguise of Wildlife Management. Sometimes, I made big drawings all over the blackboard to explain various human impacts. My students loved it!
Here, I have worked out a few of these “ecological explanations” in colourful before-and-after drawings.
I made these drawings to illustrate how hydropower plants change rivers, and how this affects us. In short, dams slow the current and interrupt both the migration of fish and the flow of sediments. Eventually, underwater plants are largely replaced by algae, rivers become deeper and even the groundwater level is affected. Decomposing organic sediment in hydropower lakes releases greenhouse gasses.
Sometimes, hydropower lakes are advertised as an opportunity for tourism. In practice, fluctuating water levels, algae blooms and unpredictable currents mean that access is often prohibited.
I initially made these drawings because I think it is important to tell the whole story, not just the propaganda from energy companies. Later on, some were used in an education campaign by Za Savo.
In these pictures, I show the effect of fertilizer, which I depict as red circles with the letter N ( from Nitrate). With little or no fertilizer, there is a highly diverse grassland community with many specialized plants and animals. This changes when fertilizer is added: then, the fastest growing grass outcompetes all other plants. Such a fertilized meadow is no longer a living space for many different animals …
The picture with the cow shows where excess fertilizer comes from: European cows are fed with plant-based food, which is grown in South America, shown as green figures in the shape of the continent. On the other end, milk is exported. But the cow-faeces, with the South American nutrients inside, stays behind in Europe …
When Common carp are released in a pond, they start a chain reaction which alters the entire underwater environment. By eating plants and stirring up sediment, they create ideal conditions for algae: the water becomes turbid and green. This release of nutrients from the sediment and from the eaten plants in the form of fish faeces is called “internal eutrophication”.
These drawings are used by municipality De Bilt (NL) to explain why they remove carp.