The Carbon Cycle

Posted Thursday, 01-May-2008 by logBlogger - Reply - Permalink

For as long as there has been life on Earth, the amount of carbon dioxide in the atmosphere has been rising and falling.

Volcanoes and forest fires emit carbon dioxide, too, just like we do when we burn fossil fuels. However, Mother Nature has a system for managing these carbon dioxide emissions and eventually removing the excess carbon dioxide from the atmosphere.

How does she do it? The answer may surprise you! A recent study highlighted in Science Daily shows that natural carbon dioxide emissions are managed through a complex feedback system that depends, in a large part, on molluscs.

Yes, that's right... molluscs.

Snails, clams, oysters, scallops and other marine life on the half shell actually play a significant role in trapping carbon dioxide and locking it away. Basically, whenever carbon dioxide levels rise, silica-based minerals such quartz, feldspar, and mica begin to break down at a faster than usual rate. The breakdown of silicates produces calcium, which is carried to the sea by rivers and streams. Then, molluscs take the calcium and mix it with carbon dioxide to form shells of calcium carbonate. The end result? The mollusc has a snazzy home, and a little bit of carbon dioxide has been removed from the atmosphere for good!

So, three cheers for the molluscs. Unfortunately, this system is only calibrated to handle natural emissions from volcanoes and hydrothermal vents. The authors of the study state that humans are adding carbon into the atmosphere at a rate 100 times faster than normal, and there simply are not enough molluscs in the ocean to take care of it all. Relying on natural cycles to clean up our mess is foolish given the rate at which we are dumping carbon into the atmosphere.

The best solution is to try to reduce emissions as much as possible now, and also to do everything possible to remove carbon from the atmosphere. The best way we have of doing that is simply to plant more trees. Trees act as a natural "carbon sink". They don't lock up carbon forever, like molluscs do when they make their shells. However, they do absorb carbon and store it throughout their lifetimes, releasing oxygen for animals like us to breathe.

Even though this carbon recycling system can't help us solve the global warming crisis, it serves as a reminder of how amazingly fine-tuned Earth's ecological balance really is. Even a small, seemingly insignificant type of animal, like a mollusc, can play an important role in maintaining this balance. It's important not to judge how important an animal or plant is to ecosystem by what it looks like.

We humans tend to pick just a few species that we really want to save, usually animals or plants that are colourful, cute, smart or showy in some way. However, just because a species isn't flashy or charismatic does not mean that we should allow it to disappear. Environmental problems such as pollution and loss of habitat are threatening many types of ocean life, including many species of snails and other shellfish.

We need to create a cleaner, more liveable environment for all species, molluscs included.