Climate Action – Can a stream reverse climate change?
As an agency focused on the conservation, protection, and restoration of water, we are always looking for ways to communicate the importance of healthy streams in Canada. We knew there was a link between healthy streams and climate action, but we’ve been doing a bit more research about this link this spring. In this 3-part Climate Action series, we will share some of the things we’ve been discussing in early 2021.
Let’s start with the basics! In this article, you will see how carbon interacts with streams. Next time, we will discuss the more permanent carbon capture ability of streams and in the third article we will find out more about the research behind streams and carbon capture.
We started noticing the ‘greenhouse effect’ in the mid-20th century, named this way because our atmosphere was causing an increased capture of heat close to the planet like a greenhouse. As human civilization used more of the earth’s materials to better our lives, we also caused more and different gases to be released into the atmosphere. Those gases were staying in our atmosphere for longer periods of time, increasing the greenhouse effect over the years.
Greenhouse gases (GHG) include chemicals, but the ones tracked by Environment and Climate Change Canada include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), perfluorocarbons, hydrofluorocarbons, and nitrogen trifluoride. What makes these gases unique is their ability to capture heat and their presence in the atmosphere. For this conversation, we will focus on carbon dioxide.
How do streams interact with carbon?
One way of explaining the carbon cycle and streams is that all living systems are made up of organisms that eat and breath using photosynthesis and cellular respiration. The real story is much more complicated, but we will start with a simple explanation.
Photosynthesis – Plants and other photosynthetic organisms (i.e. cyanobacteria and algae) capture carbon to create sugar. This allows plants to have an ever-growing bank of stored energy.
6 Carbon Dioxide (CO2) +6 Water (H2O) + Sun’s Energy -> Sugar (C6H12O6) + 6 Oxygen (O2)
Cellular Respiration – Animals eat plants and photosynthetic organisms to gain energy and create carbon dioxide.
Sugar (C6H12O6) + 6 Oxygen (O2) -> 6 Carbon Dioxide (CO2) +6 Water (H2O) + Energy.
This process is obviously much more complicated, but this is a basic way in which streams capture carbon or at least hold onto it for a little while.
Healthy streams are rich with lots of living things, creating huge biomass (living things that can be used as fuel). Each of these living things is made up of carbon, and also holds carbon in their bodies to perform photosynthesis and carbon respiration. When these organisms die, their bodies break down into rich soil around streams, and sediment in streams.
Unhealthy streams have far less biomass and therefore less stored carbon. Unhealthy streams also have infertile soil, which lacks organic matter and doesn’t store carbon as well as healthy streams.
Can aquatic systems be used to capture carbon?
The reality is that we are still discovering the truth to this answer. We know that streams can temporarily capture carbon using photosynthesis and cellular respiration to capture carbon in biomass, but we also know that there is more to this story.
In our next article, we will discuss some of the more nuanced and sophisticated ways in which streams capture carbon related to soil composition and fluvial morphology (the shape of rivers, their water, and the landforms they create).
Stay tuned for the next article in this series.
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