By Emma Heinrich
As an increasingly threatening problem, climate change action is more important now than ever. One of the biggest drivers in modern climate change is the increasing concentration of CO2 and other greenhouse gases in our atmosphere. Carbon sequestration, the process of capturing and storing carbon dioxide into carbon sinks such as vegetation, soil, and oceans (United States Geological Survey), is an integral factor in drawing out CO2 from the atmosphere. Blue carbon, carbon stored in coastal and marine ecosystems such as mangroves and marshes, is a critical point for future long-term climate change mitigation (The Blue Carbon Initiative, 2019). In recent years, the importance and potential of blue carbon coastal ecosystems have gained recognition within the scientific community and integration into climate change policy should follow suit. With current climate policy, including the 2015 Paris Climate Agreement, we are expecting to see a 3.1-3.7℃ temperature increase sustained by 50-75 billion tons of greenhouse gases emitted annually by 2100 (Nunn, Ryan, et al., 2019). With these increases, we can expect to see catastrophic effects including but not limited to: increasing frequency and severity of natural disasters, food insecurity, and human health concerns. Figure 1 shows this current climate pathway in comparison to other projections based on greenhouse gas emissions and the temperature increase expected by 2100. A key factor for the 1.5℃ and 2℃ pathways is the process of capturing and storing carbon (The Intergovernmental Panel on Climate Change). By enacting to restore, conserve, and protect these coastal ecosystems through new climate policy, we can take a significant step in the fight against climate change.
Despite their extensive significance, mangroves, marshes, and seagrasses are among the most threatened natural environments worldwide. In recent years, approximately one-half of the Earth’s coastal blue carbon ecosystems have disappeared due to human activities, directly through dredging, harvesting, and draining and indirectly through climate change impacts like sea-level rise and increasing severe weather (Macreadie, Peter I, et al., 2017). With this loss of coastal blue carbon ecosystems, these disturbances are emitting more and more ancient carbon into the atmosphere. These ecosystems are extremely important to maintain because losing one hectare of a coastal blue carbon ecosystem is equivalent to losing ten to forty hectares of native forests. This information also speaks to the blue carbon ecosystem’s staggering ability to store carbon. In Figure 2, one can see the carbon sequestration capability of mangroves, salt marshes, and seagrasses. Given 1,000 km2 of coastal blue carbon ecosystems, it is possible to sequester 11.25 Pg of carbon (Siikamäki, Juha, et al., 2013). Particularly by looking at mangroves with a considerable carbon storage to area ratio, one can deduce its importance as a coastal ecosystem. In the United States, one can find mangroves from the southern tip of Florida along the Gulf Coast to Texas. Florida’s southwest coast boasts one of the largest mangrove swamps in the world (Environmental Protection Agency). However, these regions are especially vulnerable to the impacts of climate change, especially increasing natural disasters like hurricanes, which are prevalent in the area and rising sea level, a rapidly growing threat in Florida. With the restoration and conservation of the coastal blue carbon ecosystems, we would be not only sequestering blue carbon but also contributing to other nature-based climate solutions (Wedding, L.M., et al., 2021). By improving the wide range of ecosystem services, we can improve biodiversity and sustainable development, and set these as national standards to be used in a variety of other ecosystems such as forests threatened by fires and coral reefs threatened by ocean acidification.
Critics of this strategy may suggest that climate change efforts be better suited elsewhere, such as integrating carbon-neutral business standards or new renewable energy development. Although all climate mitigation efforts are helpful, nature-based solutions like blue carbon ecosystem restoration and conservation is something to make a priority sooner rather than later due its ability to be immediately integrated and the long-term applications of carbon sequestration. Others may suggest that climate change mitigation is too expensive or may hinder industry practices, and they would opt for climate adaptation strategies. Climate mitigation entails actively making the impacts of climate change less severe by reducing greenhouse gas emissions or other strategies, as opposed to climate adaptation meaning merely reacting and adjusting to the impacts as they come. Although climate adaptation may be necessary for some situations, the focus should be on directly attacking the source, especially considering the catastrophic effects that climate change can sustain. As carbon sequestration is a process that will provide enormous benefits in the long term, it is crucial the world begins this process to set up future generations for success.
In 2022, we are past the question of “why” about climate change, but rather shifting to “how” and “when”. The restoration and conservation of blue carbon ecosystems must be an immediate priority. If not, these ecosystems are going to continue to degrade, releasing more and more ancient carbon emissions, worsening the state of our climate. By acting, the world can stop these emissions and begin work to reverse them and set up the proper expectations for climate action and research in the future.
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Works Cited
Blue Carbon. International Union for Conservation of Nature, 3 July 2020, https://www.iucn.org/resources/issues-briefs/blue-carbon.
The Blue Carbon Initiative, Conservation International, 2019, https://www.thebluecarboninitiative.org/.
“Climate Change Impacts.” Climate Change Impacts | National Oceanic and Atmospheric Administration, https://www.noaa.gov/education/resource-collections/climate/climate-change-impacts.
Global Warming of 1.5 ºC. https://www.ipcc.ch/sr15/chapter/spm/.
Macreadie, Peter I, et al. “Can We Manage Coastal Ecosystems to Sequester More Blue Carbon?” The Ecological Society of America, John Wiley & Sons, Ltd, 10 Apr. 2017, https://doi.org/10.1002/fee.1484.
Mangrove Swamps. Environmental Protection Agency. https://www.epa.gov/wetlands/mangrove-swamps.
Nunn, Ryan, et al. “Ten Facts about the Economics of Climate Change and Climate Policy.” Brookings, Brookings, 23 Oct. 2019, https://www.brookings.edu/research/ten-facts-about-the-economics-of-climate-change-and-climate-policy/.
Siikamäki, Juha, et al. “Blue Carbon: Coastal Ecosystems, Their Carbon Storage, and Potential for Reducing Emissions.” Taylor & Francis, 28 Oct. 2013, https://doi.org/10.1080/00139157.2013.843981.
“The Six-Sector Solution to the Climate Crisis.” UN Environment, https://www.unep.org/interactive/six-sector-solution-climate-change/.
Wedding, L.M., et al. “Incorporating Blue Carbon Sequestration Benefits into Sub-National Climate Policies.” Global Environmental Change, Pergamon, 8 Mar. 2021, https://doi.org/10.1016/j.gloenvcha.2020.102206.
What Is Carbon Sequestration? United States Geological Survey, https://www.usgs.gov/faqs/what-carbon-sequestration?qt-news_science_products=0#qt-nws_science_products.