If the rainforests are the lungs of the planet, then the rivers can be considered the veins and arteries.
For a significant part of human history, rivers have been very important to our species for a multitude of different reasons, taking a dip being only a minor one. Therefore, it’s no surprise we’ve dedicated one day of the year to celebrate them. As an integral part of the Earth’s ecosystems, rivers should be discussed within the realm of climate change, to truly highlight their importance. For this, we’ve gathered a few points on this topic to share with you.
Only one third of the worlds rivers remain free flowing
According to a study published earlier this year in the journal Nature, only 37% of rivers longer than 1000km remain free flowing for their entire length. For a river to be free flowing, it must remain uninterrupted by human activity i.e the building of dams. This means that the ecosystems of two-thirds of the worlds rivers have already been impacted by human activity. It shows us that even technologies which is considered sustainable – hydroelectric technologies – can actually have a significant impact on the environment.
Rivers are a carbon sink
You may already know that the ocean is one of the largest carbon sinks we have; at the interface between the ocean and our atmosphere, there is a constant exchange of carbon dioxide. Rivers are also a carbon sink, but only when they are allowed to flow into the ocean. In fact, evidence even suggests that reservoirs are actually a major sauce of greenhouse gases (including carbon dioxide, nitrous oxide and methane).
Polluting rivers leads to ocean dead zones
Hypoxic zones – more commonly known as dead zones – are areas in the ocean where oxygen concentration is so low that animals can suffocate and die. This is caused by eutrophication, when the water becomes too rich with nutrients, that plant life dominates. Upon the death of the plants, the oxygen is removed from the water in the decomposition process, suffocating the animals. The main reason this occurs is the runoff from farms entering our lakes, rivers and eventually oceans. In fact, up to 30-50% of synthetic fertilisers used will not be absorbed and run off into waterways.
Given the success of the climate strike earlier this week, a good way to prevent our rivers from being further destroyed is to protest against these sorts of developments. As a consumer, you can eat food which would otherwise be thrown away (thereby reducing the need for land and fertilisers to be used in your diet); you can eat organic food, which is likely to be cheaper from the source (perhaps a good excuse to start a food co-operative?); or, you can reduce your intake of animal products (due to the larger amount of plants and therefore land required for the diet).
Jack McGovan is a writer currently living in Berlin. Starting as a student journalist covering the energy transition, he now uses his background in chemistry to write about the many topics at the intersection of science and sustainability.