How Marine Mammals Can Help Curb Climate Change
In the quest for tackling climate change, whales could play a greater role than trees
The race is on for containing climate change. With a narrow 12-year window, or rather 11.5 years at this point, to develop and implement carbon-reducing practices and behaviors, we as a society are being forced to come up with innovative solutions for a decades-old problem.
However, what if the resources we require are much less technology-intensive than we previously thought?
Whales
Whales have an astounding potential for carbon capture. These marine mammals amass carbon in their bodies during their lives. When they perish, their carcasses sink to the bottom of the ocean together with all the trapped carbon dioxide they have accumulated throughout their lifetime. This phenomenon is known as deadfall carbon.
According to a report conducted by the International Monetary Fund (IMF)(2019):
“Each great whale sequesters 33 tons of CO2 on average, taking that carbon out of the atmosphere for centuries. A tree, meanwhile, absorbs only up to 48 pounds of CO2 a year.”
The report argues that restoring the whale population to its pre whaling era levels, the equivalent to 4 to 5 million whales, would capture 1.7 billion tons of CO2, annually. In addition to sequestering large amounts of atmospheric CO2, whales promote the production of phytoplankton. These are plant-like organisms that contribute over 50% to all atmospheric oxygen and capture the equivalent amount of CO2 as four Amazon forests or 1.7 trillion trees.
In the same IMF report, it was suggested that an increase in phytoplankton productivity of 1% would have a similar impact as the sudden introduction of 2 billion mature trees. Essentially, more phytoplankton in the oceans means less CO2 in the atmosphere.
Limitations and solutions
Yet, the road ahead is not as straightforward as it seems. Despite their potential in carbon sequestrating in theory, there are limited options for increasing the number of these large aquatic vertebrates to pre-whaling levels. Accelerating the whale population rebuilds is not a particularly easy task.
One solution could be to reduce life-threatening hazards to these animals. Entrapment in fishing nets, ship collisions, and marine plastic pollution are some of the issues preventing the recovery of many species of whales. By addressing these situations, we would ease the burden we are putting on their existence and let them naturally increase in population size. Moreover, the whole ecosystem would benefit from less human intrusion and actions. As pointed in the IMF report (2019):
“Enhancing protection of whales from human-made dangers would deliver benefits to ourselves, the planet, and of course, the whales themselves. This “earth-tech” approach to carbon sequestration also avoids the risk of unanticipated harm from suggested untested high-tech fixes. Nature has had millions of years to perfect her whale-based carbon sink technology. All we need to do is let the whales live.”
Another solution entails a decrease in fishing practices coupled with thorough fishery management, which has recently proved effective for restoring fish populations. Proper management of fish stocks directly affects whale populations since these animals rely on large fish populations as a food supply. Overfishing is, therefore, a clear threat to whale populations.
Sea otters
But whales are not the sole creatures capable of influencing carbon storage. In a 2012 study, researchers found that sea otters could help trap 150,000 to 22 million tons of carbon per year.
“Sea otters have a positive indirect effect on kelp biomass by preying on sea urchins, a kelp grazer”.
Kelp is a brown colored algae seaweed that has great potential for sequestering carbon as it uptakes a high rate of atmospheric CO2. Yet, when sea urchins feed off living kelp it results in a lower density and bed distribution of this algae meaning less absorption of CO2. The presence of sea otters has then a positive indirect effect in carbon sequestration since their sheer existence benefits kelp populations and, consequently, the uptake of CO2 from the atmosphere.
Limitations
Nevertheless, increasing the population of sea otters is an oversimplified solution for a multifaceted and complex ecosystem. These animals’ range only covers a small area of the Earth’s surface meaning that their impact in decreasing CO2 levels is not significant.
Concluding remarks
The Earth and its ecosystems are an intricate web of actions and reactions, where each player has its role. In my perspective, all our actions are interconnected meaning that there is no such thing as an isolated event. An issue of this magnitude does not get solved by addressing one variable and providing one single solution. To fight climate change we must take a holistic approach and develop a strategy that fits the whole versus the individual.
Perhaps we should broaden our horizons and understand that trees do not have to be our only focus and source of carbon sequestration. Marine animals and their behaviors, it seems, can also play an important part to decelerate and minimize the impending impact of climate change.
Restoring whale populations or increasing kelp forests could be partial solutions but certainly not the ‘one’ key to solve or delay climate change. In the end, I think we as a society should be open to creative solutions to the imminent threat we face.
To quote one of my favorite movies, Cloud Atlas (2012):
“Our lives are not our own. From womb to tomb, we are bound to others. Past and present. And by each crime and every kindness, we birth our future.”
