July 14, 2023 - Botany Boost Blog

Climate change is a global crisis that is happening now. The effects of the great damage done by humans to the environment are being experienced right now by humans themselves. Warmer temperatures are changing the weather patterns, and nature’s biodiversity is in decline. Climate change is all about too much carbon in the atmosphere. However, without carbon, life would not have appeared on earth in the first place. Carbon is essential for life on earth. It is the building block of life. Every life form, including animals, plants, and even the tiniest organisms, microbes, is made up of carbon.

So, you must be wondering how, if carbon is so essential for life, the presence of excess carbon in the atmosphere becomes a threat to living organisms on earth. The greenhouse effect is a natural phenomenon occurring in the atmosphere that helps keep the planet warm. Carbon dioxide is a major gas that is responsible for this process. Hence, too much carbon in the atmosphere will accelerate the greenhouse effect by trapping more and more heat. It makes the planet warmer and warmer and eventually contributes to climate change.

If we go back to about 700 million years ago, when plants appeared on land, carbon began to cycle in an incredible balance. A balance that allowed the origin and evolution of different life forms on Earth. Plants took up carbon dioxide from the atmosphere and pumped oxygen into the atmosphere. Then, after the appearance of humans, we started to remove carbon from the soil and release it into the atmosphere by burning fossil fuels, disrupting the incredible balance created by nature. The way we cultivate plants and carry out animal husbandry releases even more carbon into the atmosphere, resulting in a global climate crisis.

So, how do we protect the life forms on earth from this global crisis? Of course, we should stop releasing carbon into the atmosphere and remove the excess carbon to get the carbon cycle back into balance. The question is, where do we put this excess carbon? We all know that plants can fix carbon in the atmosphere through photosynthesis and convert it into carbohydrates and sugars. Then these carbohydrates and sugars are pumped through the plant roots into the soil, where microorganisms can utilize them. This process is called carbon sequestration. Hence, safeguarding plants helps mitigate this global climate crisis. But recently, an even more advantageous climate mitigation opportunity has been discovered, which is to protect the blue carbon in coastal and marine ecosystems.

Fig. 1: A mangrove forest

Blue carbon is the carbon stored in marine and coastal ecosystems. These ecosystems consist of sea grass, mangrove forests, salt marshes, and phytoplankton in the oceans. Blue carbon ecosystems are considered one of the most productive ecosystems on earth. Sea grass, mangrove forests, and salt marshes are much smaller than terrestrial forests. Yet they can fix carbon at a rate of about 40 to 50 times faster than terrestrial ecosystems. Most of the carbon in these ecosystems is stored below ground and is often thousands of years old.

Fig. 2: Sea grasses

Fig. 3: Salt marshes

The oceans contain 50 times more carbon than the atmosphere. Hence, the ocean is considered the largest active carbon sink, consisting of marine plants such as seaweeds and phytoplankton. Phytoplankton are considered the primary producers of the sea. Marine organisms consume phytoplankton and seaweeds to build their bodies and skeletons. When marine life dies, the carbon stored is buried in the sea bed, locking it away in the ocean sediments.

Fig. 4: An adult sea turtle consuming sea grass leaves

In Addition to carbon sequestration, these ecosystems bring many benefits to both humans and the environment. They are considered one of the most diverse habitats on earth. They provide nursery grounds for fish, support industries like fisheries, and improve the water quality along coastlines. Moreover, blue carbon ecosystems are essential to coastal protection as they prevent coastal erosion and extreme weather events like floods, storms, tsunamis, etc.

Yet these ecosystems are severely threatened by human activities and are declining rapidly. Mangrove forest exploitation due to agriculture, coastal and marine pollution, and industrial and urban coastal development projects are some causes. Globally, mangrove deforestation occurs at a rate of 2% per year and accounts for about 10% of global greenhouse gas emissions. Blue carbon ecosystems play an essential role in storing excess carbon. But the destruction of the habitat makes them a source of greenhouse gas emissions. When deteriorated or destroyed, they emit massive amounts of carbon into the atmosphere that have been sequestered for millions of years, which is similar to a carbon bomb. Thus, these habitats play a vital role in mitigating climate change, unless they deteriorate. So we must protect and restore these ecosystems through the implementation of suitable national and international climate policies and community-led projects to attenuate the climate change issue.

Fig. 5: Deforested mangrove forest in Madagascar

The clock is ticking. There is not much time left for us. We need to act soon before the consequences of our actions become irreversible. Remember when I mentioned earlier that we need to stop releasing carbon into the atmosphere and remove the excess carbon to get the carbon cycle back into balance? Hence, we have to keep in mind that blue carbon will not solve this global problem entirely unless we find ways to stop the release of carbon into the atmosphere. Blue carbon is only an opportunity to mitigate the global climate crisis. And the fate of planet Earth lies in the decisions made by you and me.

IT IS NOT NATURE THAT WANTS HUMANS IN ORDER TO SURVIVE BUT HUMANS WHO DESPERATELY NEED NATURE TO THRIVE!

References

https://climate.nasa.gov/effects/

https://climatekids.nasa.gov/greenhouse-effect/

https://www.thebluecarboninitiative.org/

https://www.whoi.edu/know-your-ocean/ocean-topics/climate-ocean/blue-carbon/

Image courtesy

Featured image

https://images.squarespace-cdn.com/content/v1/5bb9f390da50d330b261fdc8/1626717704901-7BSFO8256SC3ZNS5SSLX/A+Maze+of+Mangroves?format=1000w

Figure 1

https://www.bluecarbonsociety.org/images/home/mangrove.png

Figure 2