Mangroves could play a significant role in addressing climate change. In the world of climate projects mangrove forests are classed as ‘nature based solutions’, which means they exist in nature and would continue to exists if humans disappeared, and that they are good at dealing with impacts of climate change.

They can suck up carbon, protect coastal areas, and are usually home to large and diverse ecosystems. They’re great. But they’re also in danger because of the very thing they’re good at protecting against. Let’s learn about them, yay.

Imagine for a moment that you, are earth. You know there is going to be lots of carbon dioxide in the air because a lot of the things that live on you literally expel it from their mouths. You also know that some of the most scenic and hospitable parts of you are on the coastline, both on land, and in sea. You know you’ve done a good job of dealing with things on land, you’ve evolved lots of nice trees, and in the ocean you went nuts with lots of lovely coral and algae. Nice. Good job earth.

But where the land meets the sea, where earth turns into mud, and rock becomes sand, you need something stronger. You need something that can handle a harsher environment, that can manage terrestrial and aquatic environments, but that also protects ecosystems and deals with all those damn carbon breathers. Enter, mangroves.

What mangroves are

Mangroves are trees that you typically find as part of a forest. They grow in low-oxygen soil in tropical and subtropical areas, they hate the cold. They are found all around the globe occupying more than 150,000 km² in more than 123 countries. You’d recognize them by their dense tangled roots that are like stilts buried into sediment under the water. The science names for the three most common mangrove trees are: Rhizophora racemosa , Rhizophora mangle , and Avicennia germinans, in case that means anything to you.

Why mangroves are good for the planet

They’re great for four main reasons; they cultivate large productive ecosystems, they protect coastal lands and ecosystems from erosion and other geological affects, they are really good at carbon sequestration (sucking carbon dioxide out of the atmosphere), and they have had, and continue to have, positive effects on local communities.

Ecosystems

A mangrove forest has countless tangled ‘aerial’ root systems that descend from their lush canopies, through air, through water, and into the earth. Beneath, above, and between these roots you’ll find heaps of living things. The canopy provides shelter, the root systems provide lovely nooks and crannies for various creatures, and the roots are especially good at making the area below the water attractive to a range of flora, fauna, micro organisms, fish, crustaceans, and probably other things I can’t think of.

Water beneath mangroves is such good real estate because mangrove roots are especially good at filtering salt out of the water and excreting what it doesn’t need. This allows them to thrive where the sea meets the land, aka where sediment from the sea washes up and the roots break down what’s below the ground, to release those sweet sweet minerals.

Coastal protection

A mangrove’s roots really do great work. Because the land on which they grow is typically soft and subject to change their roots have to be strong, they run deep, and tangle themselves, clinging to the ground. This allows them to handle the daily rise and fall of tides but also lets them withstand storms and heavy waves.

This isn’t just good for them, like duh, I can put on a coat and go out in a storm, but they also behave as natural wave breaks. Before storms make it to land and wreak havoc they trip over and have to tangle with the tangles of mangrove forests. Research in 2019 found a lot of reason to believe that “healthy mangroves contribute to significant savings in coastal rehabilitation and maintenance costs by protecting embankments from breaching, toe-erosion, and other damage.”

Carbon sequestration

Mangroves are suckers. Carbon dioxide suckers. While their ability to take carbon dioxide out of the air isn’t unique to them, and their ability to do so is dependent on sediment, temperatures, sea level rise, and other stuff; they’re just really good at it.

The muddy soil mangroves live in is typically already extremely carbon-rich and then mangroves come along and add to this store and (crucially) hold onto it. The amount of carbon stored beneath mangroves is estimated by the WWF to be up to four times greater than that stored by other tropical forests. When compared to other forest formations they prove to be significantly more productive.

Communities

With proper care mangroves provide opportunities and do a lot of good for local communities. They can be part of the ecosystem and find food within the mangroves, that same ecosystem attracts investment in the form of conservation and ‘reef tourism’, and they provide surge protection from storms. As the climate changes more and extreme weather becomes more common, natural defenses like a mangrove forest are going to play a growing part in protecting communities from the worst.

Danger! Mangroves, look out!

I’m not going to spend too long on this one but it’s important to note it’s not all sunshine and rainbows. Mangrove forests suffer from climate change and without investment and human intervention we could end up loosing them faster than they can help us.

Consequences generally accepted to be the result of climate change like sea level rise, increased storminess, and increasing temperature are likely to have a serious impact on mangrove populations at regional a scale. And on a local level the impacts could vary considerably.

To a simpleton like myself it seems that if we pay attention, we can manage this. If mangroves are impacted by temperature increases, sea level rises, and storms in one place, it surely means they can be established in new places too? We could work to maintain existing forests, but also get cultivating new forests and start spreading this super tree to more places.

To conclude

This was longer than I thought it would be but I got really into researching the basics of mangroves. They’re great, I hope after reading this you agree and know why. If you have indeed read this far and if you let me know I’ll consider doing another mangrove article that explores the different methods and projects and companies that are already investing in mangroves as a way to take climate action.

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