08 • 07 • 2020

Restoring our Coasts to Combat Climate Change

By Katie Day

Amidst many of the global events that we have experienced this past year, climate change and coastal degradation remains an omnipresent threat as both an independent issue and as a phenomena with the potential to exacerbate our current conditions. Despite the efforts of individuals and grassroots organizations to take up environmentally-conscious behaviors and encourage policymakers to make strong environmental decisions, it often feels like we are at a standstill—if not moving backwards—on our way towards comprehensive and wide-ranging mitigation and adaptation strategies. This stasis is a result of governments and industries failing to take stronger action to reduce their emissions, but it’s also due to uncertainty as to how our climate is changing and warming, and, even more so, uncertainty regarding the best approach to resolving these issues. 

One of the biggest uncertainties that has impeded predicting and mitigating climate change is how much the Earth is likely to warm. A 2014 report from the Intergovernmental Panel on Climate Change (IPCC) has predicted that the Earth could warm anywhere from 1.5ºC (given the best case scenario of carbon reduction and behavior changes) to 4.5ºC (given the worst case or “business-as-usual” scenario). To construct this temperature range, scientists sourced data from numerous climate models running different possibilities given the historical environmental record, the present conditions of the climate, and behaviors practiced within and between our societies. These scenarios are not only vital to devising our best options for reducing greenhouse gas emissions, but also for educating our communities and policymakers on the necessary changes that must be made to impact global warming and other issues of climate change. 

A recent study has been released that may provide a bit more certainty to how much the Earth is projected to warm. The study reduced the likely warming range to between 2.6ºC to 3.9ºC. This new range is a product of decades of research to better understand how the Earth’s systems dynamically interact, exchange, and influence changes within each other. While these results may provide us with a better idea of what to expect, it also comes bearing grim news: it seems that the best case scenario of the Earth warming by only 1.5ºC is now well out of reach.

Although grim, this new information may be effective in placing our governments in the hot seat, lighting the proverbial fire beneath the chair to finally force change. In their latest report, the IPCC recommended that in addition to immediate and large scale reductions in the emissions of greenhouse gases, massive carbon offsets and sequestering programs would be needed at large and extremely efficient scales in order to limit global warming. The IPCC also insists that the decarbonization of our energy and technological sectors needs to be matched by concurrent efforts to physically remove carbon from the atmosphere. 

But even with this new information and recommendations, how do we limit global warming to the new best case scenario of 2.6ºC warming? One solution may lie in some of our favorite places at Surfrider: our beaches and oceans.

The insurmountable task presented by the IPCC is already underway along our coastlines. The beaches and oceans across our planet act as large carbon sinks, specifically for “blue carbon.” Blue carbon refers to the carbon captured and released by the world’s oceans and coastal systems through the natural carbon cycles within mangroves, seagrass meadows, salt marshes, and kelp forests—and maybe even coral reefs—to sequester and store carbon for thousands of years. These ecosystems have been targeted as key areas in the search for natural and artificial carbon sinks to aid in the reduction of atmospheric carbon dioxide and limit global warming due to the efficiency of carbon sequestration and their global presence. 

In fact, blue carbon habitats are more efficient at carbon capture than terrestrial forests. 

It is estimated that blue carbon ecosystems have sequestered approximately 5,227 tons of CO2 equivalent per hectare, compared to terrestrial forests which have been estimated to sequester about 800 tons of CO2 equivalent per hectare.

Summary of estimated carbon sequestration benefits (ton of carbon dioxide equivalent per hectare of habitat) stored in soil organic carbon (brown) and in living biomass above ground (green) in each identified ecosystem. Graphic sourced from IUCN Blue Carbon.

While blue carbon habitats have the potential to be carbon sink powerhouses, these ecosystems are at severe risk due to their positioning at the interface between highly-developed coasts and our oceans. 

The deforestation and deterioration that has taken place due to improper aquaculture, urbanization, coastal landfills, and the indirect effects of pollution and upstream use has had a negative effect on the efficiency of blue carbon habitats. Over the last 50 years, mangrove forests have declined by 30-50% and these stressors are causing mangroves to release carbon, rather than sequester it. Coastal degradation has resulted in the global loss of marshes at an annual rate of 1-2%, but it is predicted that in the US salt marshes are being lost at an annual rate of 9%. And while seagrass meadows and kelp forests are considered to be resilient to oceanic degradation, increasing instances of disturbances, including kelp and seagrass harvesting, native and invasive plant competition, El Nino events, and pollution, are all leading to rapid declines in  ecosystem health and resiliency.

It is time we enter into a symbiotic relationship with blue carbon ecosystems: while these environments have the potential to be sites for incredibly efficient carbon offset programs, they also need our help to restore their health, resiliency, and longevity. 

Investing in the restoration of global coastal and ocean habitats will not only revitalize these important nature sites, but will also enhance their ability to perform the offset and sequestration of carbon emissions at the scale suggested by the IPCC. There are numerous organizations that have begun to form such a relationship with blue carbon habitats, fostering programs to help drive much needed funding and attention from individuals, businesses, and nations aiming to mitigate climate change impacts and global warming. For example, among the numerous restoration programs, the Blue Carbon Initiative and the Nordic Blue Carbon Project are international projects that aim to educate and provide opportunities for blue carbon restoration and sequestration projects.

Surfrider’s own Ocean Friendly Gardens aims to reduce run-off pollution, improve water retention, and cultivate carbon sequestering soils. Another US-based organization, SeaTrees, has been focused on restoring mangrove forests, coral reefs, kelp forests, and seagrass meadows and increasing biodiversity on the world’s coasts. Through the support of existing organizations and the founding of similar initiatives, we can restore and protect coastal ecosystems, preserving the beauty, diversity, and efficiency of these habitats, all while building momentum in the effort to reduce carbon in the atmosphere through blue carbon sequestration.

To learn more about blue carbon cycles, ecosystems, restoration and ongoing offset efforts, check out the Blue Carbon Beachapedia article!