Mangroves Over Carbon Capture Technologies:
The Case for Natural Climate Solutions
Solutionism at the Forefront
The history of human evolution is intertwined with the development of technology. From the creation of simple stone tools to the sophisticated digital technologies of today, our species has consistently harnessed technology to overcome challenges and improve the quality of human life.
Our brains have evolved to understand and manipulate our environment, leading to the creation of tools that extend our capabilities. Often, this comes at a great cost to the natural world.
This inclination towards technological solutions is a fundamental aspect of our species’ evolutionary journey and it continues to shape human development in the modern world. However, this tendency to prioritise technical and often untested solutions has caused us to neglect the imperative of preserving the delicate balance of the natural systems upon which we depend, threatening the long-term habitability of the planet.
I’ve been thinking about this coevolutionary interplay between human evolution and technological progress for a long time. Solutionism, the ideology that assumes that every problem can be solved with a technological fix, often without fully understanding the complexity of the problem, can lead to unintended consequences. An example of such solutionism is the technology of Carbon Capture and Storage (CCS).
Do we overlook what is in front of our eyes?
The discussion around CCS, a high-tech solution that aims to reduce the release of carbon dioxide (CO2) into the atmosphere from industrial processes and fossil fuel combustion, which are significant contributors to climate change, has so much intensified in recent years, that overshadows the natural processes that play a vital role in the Earth’s carbon cycle, the biological and the geological processes.
We all taught about it at school. It is one of the most crucial processes that sustains life on Earth. Still guessing? You are not the only one. We often focus on technological advances to resolve problems, to the extent that we forget the fundamental processes that operate before our eyes. I am talking about the most powerful carbon absorption mechanism, Photosynthesis.
Without photosynthesis, life on Earth as we know it would not be possible. It is the foundation of most food chains, provides the oxygen we breathe, and plays a crucial role in maintaining the balance of gases in the atmosphere. It is the most important, time-tested process of carbon sequestration, which has been regulating the Earth’s climate for millennia.
Let's take a trip back to our school days, when we first learned about the wonders of photosynthesis in our science classes. Remember how fascinated we were by the idea that plants could harness the power of sunlight to create their own food? It was like a magic trick unfolding before our own eyes. Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy in the form of glucose- the fuel that powers their growth and development. During this process, these organisms take in carbon dioxide (CO₂) from the atmosphere and water (H₂O) from the soil, using the energy from sunlight to transform these molecules into glucose (C₆H₁₂O₆) and life-give oxygen (O₂) that we breathe. The general equation for photosynthesis is:
6CO2+6H2O+light energy→C6H12O6+6O2
Mangroves and Blue Carbon
You might be wondering why I am delivering this fundamental science lesson. The reason is mangroves and the harm we cause to mangroves’ blue carbon ecosystems. Blue carbon is simply the term for carbon captured by the world’s oceans and coastal systems. It most commonly refers to the role that tidal marshes, mangroves, and seagrasses can play in carbon sequestration. Mangroves in particular are not just trees; they are superheroes of the carbon world, sequestering carbon (that is, they suck up carbon dioxide from the air to store in their roots and branches as well as the sediment that collects around them) at a rate far surpassing that of terrestrial forests. Mangroves absorb between 15 and 18.3 million metric tonnes of carbon annually. For comparison, an average car emits about 1.6 metric tonnes of carbon dioxide a year. That means that mangrove forests worldwide absorb the same amount of carbon yearly as removing 4 million cars from the road for a year. If undisturbed, this carbon stays there for millennia. Mangroves are therefore crucial in fighting climate change.
However, they do not remain undisturbed. Coastal development and urbanisation, rising sea-levels, pollution and evasive species are just a few of the factors threatening mangrove ecosystems worldwide. This leads to the release of stored carbon back into the atmosphere, further contributing to climate warming. From the Caribbean coast alone “some 50 percent of mangroves have been lost over the past three decades, due to cattle ranching, roads and tourism” said María Claudia Diazgranados, a marine biologist and CI’s blue carbon director in Colombia, in an investigation run by The Guardian in 2021.”
And these are not the only threats to mangrove trees. The authors of a recent paper published in the journal Frontiers in Marine Science discuss the impact of human activities on microplastics (particles <5 mm diameter) enrichment in mangrove blue carbon ecosystems in Zhanjiang Bay, China. Their findings suggest that mangrove sediments have a higher abundance of microplastics compared to non-mangrove sediments, indicating that apart from locking away carbon, they also operate as potential sinks for microplastics.
Microplastics consist of carbon and hydrogen atoms bound together in polymer chains. They are not biodegradable, which means they do not readily break down into harmless molecules. They can take hundreds or thousands of years to decompose. They are found everywhere. I mean everywhere; they have been detected in marine organisms from plankton to whales and in commercial seafood. Microplastics have been found in drinking water sources, including tap water and bottled water which has been found to contain alarmingly high levels of microplastic contamination, far exceeding previous estimates. Several studies have confirmed the presence of microplastics in human breast milk samples, indicating that these particles can potentially transfer from mothers to infants during breastfeeding. A recent study also found that the detection of microplastics and nanoplastics (MNPs) in carotid artery plaque is associated with an increased risk of cardiovascular events, further highlighting the potential impact of plastic pollution.
Carbon Storage and Sequestration (CCS)
Carbon Capture and Storage (CCS) is a technology aiming at reducing the release of carbon dioxide. The CCS process involves three main steps:
Capture: CO2 is separated from other gases produced at industrial process sites or power generation facilities.
Transport: The captured CO2 is then transported, usually via pipelines, to a suitable storage site.
Storage: The CO2 is injected into underground geological formations, such as depleted oil and gas fields or deep saline aquifers, where it is stored securely and indefinitely.
Sounds good, right? Who wouldn't like a modern, high-tech approach to capture carbon and then bury it somewhere underground? It is, indeed, consistent with the evolutionary development of the human brain, which has evolved to manipulate our environment through the creation and use of tools and technology.
But wait a second. Think of the scale of the challenge, the number of the CCS projects required and the urgency to get them up and running. Fossil fuel corporations have been preaching the gospel of CCS in their efforts to secure public licenses, yet the industry's promises have not actually materialised. The findings reveal a series of missed carbon capture targets; budget-overruns, and hundreds of millions of dollars of costs to taxpayers in the form of subsidies.
A review of 12 large-scale CCS projects published on September 2023, on DeSmog, the journalism platform focused on investigating and reporting misinformation campaigns related to climate change and environmental issues, revealed “a litany of cost-overruns and missed targets, with a net increase in emissions.”
CCS demands significant infrastructure investments for its implementation. This includes the construction of large-scale capture plants, that are both capital and labour-intensive. Once captured, the CO2 must be transported—often across hundreds of miles—via a network of pipelines to designated storage sites
Developing these injection sites involves extensive surveying, drilling, and well construction activities, all of which are resource and labour-intensive. Furthermore, substantial investments are required for materials, such as steel, concrete, aluminium, and plastic, essential for building this vast infrastructure. Ultimately, the energy required to build and operate CCS facilities presents a paradox. Although CCS is designed to reduce greenhouse gas emissions, the energy-intensive processes involved in these facilities can lead to a substantial increase in emissions.
The Remarkable Value of Mangrove Ecosystems?
As we face the challenges caused by climate change and environmental destruction, we must embrace solutions that work in harmony with nature’s delicate balance. In this context, the conservation and expansion of mangrove forests emerge as a profoundly effective approach that provides far more than just carbon storage. Mangroves possess a remarkable ability to sequester and store carbon over the long term, particularly when their habitats remain undisturbed. This contrasts with CCS technologies, which demand massive, complex and potentially risky investments in infrastructure and are unlikely to even make a small dent in global emissions. Quoting Vaclav Smil, an energy expert at the University of Manitoba, “carbon sequestration is irresponsibly portrayed as an imminently useful option for solving the challenge (of global warming).”
Beyond carbon sequestration, mangroves provide habitat for a wide range of species and offer natural protection against coastal erosion and storms. Preserving mangrove ecosystems has major economic benefits too. They support the livelihoods of many coastal communities through fishing and eco-tourism, creating prosperity while protecting the environment.
In contrast to technological solutions like CCS, which require intensive resource demands, extensive infrastructure, and high operating costs, the conservation and expansion of mangroves represent a more sustainable and cost-effective approach.
By prioritizing mangrove protection and growth, we choose a natural solution that aligns with environmental and economic sensibilities, ensuring the preservation of these vital ecosystems for future generations. This sustainable approach allows people to thrive within the ecological limits of our planet while safeguarding the delicate balance of nature that sustains us all.
Bibliography
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