Seagrass meadows store as much carbon per hectare as trees, but the seagrass keeps the carbon stored longer.
Trees capture about 27 million tons of carbon annually, but when a tree dies, it releases that carbon back into the atmosphere. Don’t get me wrong; trees are an excellent carbon sink.
Seagrass meadows also capture about 27 million tons of carbon each year, but they bury it in the soil beneath them. As long as the meadow continues – not just the individual plant – that carbon stays buried.
The seagrass meadows are being dredged or destroyed by pollution and climate change at a rate of about 1.5% each year. Since the meadows have been storing carbon since the last ice age, there’s potentially 20 billion tons of carbon beneath them, waiting to be released into the atmosphere.
Artificial carbon sequestration under the ocean has been considered. It has drawbacks and the techniques are not yet proven to last. Replanting seagrass and protecting existing meadows looks like a much cheaper and proven way of accomplishing the same end.
Seagrass photo via Shutterstock