Ten by Earth Day 2021: Blue Carbon as a solution to climate change
October 2, 2020
The legacy of the first Earth Day in 1970 is rooted in the sweeping environmental laws and regulations that followed as a result. Much of this legislation is now under threat today. In honor of the 50th anniversary, and now with less than 35 days until the November election, EARTHDAY.ORG is rolling out the policy initiatives we want to see within the first 100 days of the next administration, by Earth Day 2021.
This blog is the eighth in our series and focuses on the ability of blue carbon to mitigate carbon emissions and stop temperatures from rising past 1.5° C.
I think I speak for all of us when I say the climate crisis can really make me blue, but, what if blue is just the answer we’ve all been looking for?
Blue Carbon cycles are responsible for sinking significant amounts of global carbon annually in our oceans. The natural carbon capturing processes of marine animals and surrounding ecosystems constantly work in tandem, creating cycles that ensure that carbon is constantly being absorbed and stored in organisms and sediments on the ocean floor.
A Whale of a Solution
Take, for example, whales. Seemingly unlikely heroes for the climate crisis, but incredibly effective in their carbon cycling.
There are several ways whales play a role in regulating blue carbon. One way they do this is by shuttling carbon to the deep sea. A study published in 2010 estimated that eight types of baleen whales, including blue, humpback and minke whales, collectively transport nearly 30,000 tons of carbon into the deep sea each year as their carcasses sink. Furthermore, if great whale populations rebounded to their pre-commercial whaling size, the authors estimate whales could sequester 160,000 tons of carbon a year.
Additionally, great whales’ waste helps facilitate carbon capture while they’re still alive. As these whales move from deep water to the surface, they release enormous plumes of nutrients like nitrogen, phosphorus and iron into the water. By bringing nutrients from deep waters to the surface, they stimulate the growth of small marine plants known as phytoplankton, which absorb carbon via photosynthesis and serve as a food source for other marine species.
Is There Anything Trees Can’t Do?
Of course, there are other sources of blue carbon sequestration and unsurprisingly, one of the most productive ecosystems is the mangrove forest!
Mangroves are a group of trees and shrubs that are found in coastal, intertidal zones. These plants live in saltwater and have enormous capacity to store carbon dioxide and other greenhouse gases, trapping the carbon in these gases and storing them in flooded soils for millennia. At the same time, mangroves prevent massive flooding and coastal erosion and also provide essential nursing ground for fish, invertebrates and even mammals.
Being Salty Is Key
One other significant ecosystem is salt marshes. Salt marshes are coastal wetlands that experience daily flooding and ebbing of saltwater brought in by the tides. Like mangroves, they provide a host of services, but specifically salt marshes are incredibly effective at removing carbon from the atmosphere and storing it in their tissues as well as in the soil.
What’s the Catch?
In terms of harm to humans, there isn’t really any catch. However, protections have rolled back in recent years for these important organisms and ecosystems. Salt marshes and mangrove forests are not as abundant as they once were, with industries clearing these spaces for resorts and shrimp farms.
Join us to Restore Our Earth and take action in your community to make sure our coastal systems remain healthy.