The Most Important Plant You Overlooked—Seaweed

Bare feet crossing sun-baked earth. Villagers huddling around a disappearing well. Shriveled plants rotting in an abandoned field. These are but a handful of the images associated with a water-scarce future—one that could soon become reality as “population growth and economic development [drive] increased water demand throughout the world,” says Charles Iceland, global director for water at the World Resources Institute. “Meanwhile, climate change is decreasing water supply and/or making rainfall increasingly erratic in many places.” This dual effect of spiking demand and volatile supply has already had devastating consequences. A notable example is Cape Town’s widely publicized 2017 water crisis, which nearly brought the city to its day zero—the day when the water supply is estimated to run out. Without rapid worldwide action to address the causes and effects of climate change, other cities such as Mexico City and entire regions such as the Tigris-Euphrates Basin, which encompasses Turkey, Syria, and Iraq, could soon face their day zero. To minimize damage from water scarcity and a myriad of other climate change-associated crises, lawmakers must leave no policy tool, however unconventional, off the table. 

Climate Solutions–Future Benefits, Present Costs

In its Sixth Assessment Report, the Intergovernmental Panel on Climate Change found that current climate inaction is driven more by a lack of political willpower than by a lack of scientific evidence; a perfect storm of political challenges including the long-term accrual of climate damages, the difficulty to link specific events to climate change, and the incentive for countries to free-ride off of other countries’ climate action make it difficult to politically justify costly action. If unaddressed, a lack of political willpower could fuel a dangerous self-fulfilling prophecy by making climate action more costly, and thus even less politically palatable. 

More broadly, many legislators and members of the public alike hold the false assumption that a single policy initiative can be a panacea for all climate problems. While such a proposition may make sense to politicians looking to win reelection, it effectively crowds out economic and political capital for smaller-scale solutions that could be more cost-efficient. This is particularly evident in the absence of one of the most underutilized natural solutions to climate change—the oceans—from most major climate initiatives

Kelp to the Help

Growing seaweed is inherently more sustainable than most land-based plants; it does not require agricultural inputs such as water-intensive feed, pollutive synthetic fertilizers, and expansive plots of land. Where conventional land-based farming causes environmental degradation, cultivating seaweed restores the marine environment; it crucially offsets ocean acidification and eutrophication—climate change-associated processes that reduce marine biodiversity—by absorbing carbon dioxide, nitrogen, and phosphorus.

When it comes to mitigating rising temperatures in the global environment, a particularly urgent concern in the industrial space is transitioning away from non-renewable energy and single-use packaging; one promising solution is to create biofuels and bioplastics from seaweed, which has a significantly lower carbon footprint than land crops like corn (used to create ethanol). At the same time, seaweed aquaculture is emerging as a low-tech yet surprisingly cost-efficient alternative to complex carbon capture facilities in the budding carbon offset market. In fact, cultivating seaweed in just 5 percent of US waters can effectively sequester the carbon output of 20 million cars

Even with more than 48 million sq km of suitable ocean area, however, just six Southeast and East Asian countries produce about 97 percent of the global harvest. While several countries specializing in seaweed production may be optimal from a purely free-market perspective, more countries must increase their seaweed production in order for seaweed to have a significant impact on climate change. 

Seaweed farmer in Bali, Indonesia. By Anton Raharjo.

Environmental Externalities

With so many economic and environmental benefits, an obvious question is: why are so few countries supporting their seaweed industry through significant policy intervention? As is often the case, the reason (and solution) comes down to basic economics. 

On the demand side, most seaweed is currently used for direct human consumption, which is relatively unpopular outside of Asia where the majority of seaweed is produced. On the supply side, the low material cost of starting a farm decreases the farm gate price of seaweed and increases the share of labor in total expenses, disadvantaging higher-income Western countries. Regardless of location, however, the inability of producers and consumers to fully internalize the positive environmental externalities of seaweed means that it is underproduced and underconsumed relative to its socially optimal quantity. 

To correct such a market failure, policymakers must incentivize seaweed production beyond the market-determined quantity. However, most governments have done little to support their domestic seaweed industry due to a confluence of factors. In the same way that policymakers have often failed to leverage the environmental benefits of the ocean, which are less salient than established policies such as carbon taxes, many policymakers are still unaware of the environmental benefits of seaweed.  On the academic side, evidence on the emerging role of seaweed as a tool to combat climate breakdown has also been limited compared to research on tried and true climate policies.

A Developing Success

Some governments, most notably India, have been aggressively supporting seaweed farming in response to the rapidly rising cost of procrastinating climate action. Around the turn of the 21st century, India implemented a public-private seaweed partnership; the State Bank of India granted around $300 million in loans to more than 540,000 seaweed aquaculture groups, while PepsiCo India purchased the harvests from these groups. Jumpstarted by this support, India’s seaweed production has increased more than 119,000 percent from just 21 tons in 2001 to more than 25,000 tons in 2020.

Indian Seaweed Farmers Checking Lines. By Bhaskar.

In addition to boosting its economy, the rise of India’s seaweed industry has had numerous social benefits in the form of restoring marine habitats, reducing overfishing, and providing economic opportunities for marginalized, disproportionately underbanked groups of farmers such as women. The case of India’s success in the face of being one of the world’s poorest countries motivates other coastal nations to support seaweed farming as a way to simultaneously promote the economic welfare of their citizens and the welfare of the global environment. 

The Way Forward

Environmental and economic benefits notwithstanding, farming seaweed is neither a feasible course of action for all countries nor a silver bullet in the effort to tackle climate breakdown. Beyond its tangible benefits, seaweed farming encourages policymakers to rethink the conventional public-policy approach. With many countries reneging on their climate pledges, it is improbable that pressuring reluctant countries to make additional quixotic pledges will generate the speed and scale of climate action necessary to prevent catastrophic global warming. On the other extreme, relying on policies that exclusively favor economic efficiency over environmental benefits is unlikely to do much good either. When we seek to understand the consequences of a lack of political will, it is evident that humanity’s fight against climate change should not be defined by a few major initiatives promising to cut carbon emissions by twenty or thirty percent, or a thousand economically conforming policies each with near-zero impact. Rather, it should be focused on creating a comprehensive portfolio of a hundred solutions, each with a one percent benefit for the economy and the environment—even if it means searching in the (sea)weeds. 

Zunian Luo is a Junior at Weston High School (MA) focused on the intersection of economics, data science, and environmental sustainability. He is a Research Assistant at the Columbia University Department of Economics PhD program and an Intern at the Kenneth C. Griffin Department of Economics at the University of Chicago. Soon after his sophomore summer Zunian published his quantitative environmental economics thesis titled “Cap or No Cap? What Can Governments Do to Promote EV Sales?” at the Cornell Undergraduate Economic Review as the first high school student published by the journal. In addition to writing about seaweed, he also farms seaweed in Chatham, MA. In his free time he enjoys taking photos with his drone and playing tennis.