Oceans Can Help Tackle Climate Change

According to the U.N. Intergovernmental Panel on Climate Change’s Special Report on the Ocean and Cryosphere in a Changing Climate, warming global temperatures are causing rising sea levels, ocean acidification, disappearing glaciers, loss of sea life, and marine heatwaves. To address these problems, several heads of government who are committed to improving ocean health formed the High Level Panel for a Sustainable Ocean Economy (HLP).

The HLP enlisted ocean scientists and experts to write a report, The Ocean as a Solution for Climate Change: Five Opportunities for Action, detailing the ways the ocean can be used to reduce greenhouse gas (GHG) emissions, adapt to climate change, and support the United Nations’ Sustainable Development Goals (SDGs). On October 3^rd, several country ambassadors and authors of the report gathered at an event hosted by the World Resources Institute to present their findings and suggestions.

The report emphasizes that, while “recent attention is focused on the problems that the ocean faces, the ocean is also a source of potential solutions and innovation.” The report outlines five recommendations that have the potential to combat climate change by providing a fifth of the global GHG emission reductions needed to stay under global warming of 1.5°C. The five opportunities for action outlined by the report are:

 

1. Ocean-Based Renewable Energy

Germany's first offshore wind farm, the Alpha Ventus Offshore Wind Park. (credit: Martina Nolte)

The development and implementation of renewable ocean-based energy would decrease carbon emissions and allow for sustainable development. The experts looked at a number of potential options, such as fixed and floating offshore wind turbines, floating solar PV panels, and tidal energy. At scale, these options have the potential to replace coal-fired power plants and decarbonize the energy sector. However, the report does not outline a plan for energy transmission from ocean-based renewable energy sources to the coasts, which will be a critical step for these energy sources to be effective.

 

2. Ocean-Based Transportation

Shipping and ocean transportation currently account for 3 percent of global anthropogenic GHG emissions, and current global trends show a doubling of GHG emissions from the marine shipping sector by 2050. To reduce these emissions, the report recommends using alternative fuels, like biofuels, to replace fossil fuels, and retrofitting existing ships to implement energy-saving technologies and practices. Decreasing emissions from ocean transportation would have the additional benefit of reducing sulfur emissions, which are harmful to people in coastal cities. It would also slow ocean acidification by reducing seasonal “hotspots” caused by strong acids formed from shipping emissions.

 

3. Coastal and Marine Ecosystems

A number of nature-based solutions, including ecosystem restoration and conservation, are included in the report. Mangroves, salt marshes, and seagrass are blue carbon ecosystems, meaning they absorb carbon and store it in their roots. By protecting these ecosystems, carbon can be removed from the atmosphere. The restoration and expansion of blue carbon ecosystems would further reduce carbon in the atmosphere. Such ecosystems also help protect coastal communities from the impacts of extreme weather and flooding, which are exacerbated by climate change.

 

4. Fisheries, Aquaculture, and Dietary Shifts

Improving the efficiency of fisheries and aquaculture, while simultaneously promoting the consumption of ocean-based foods, could also be a climate solution. According to one of the panelists and authors, University of California Professor of Marine Science Steve Gaines, ocean-based foods (i.e., fish and crustaceans) are more water and energy efficient to produce than land-based foods, and therefore require less carbon to produce. By promoting the consumption of ocean based-food, the food industry could potentially mitigate between 0.48-1.24 gigatons of carbon dioxide by 2050 (equivalent to eliminating emissions from 123 to 319 coal-fired power plants).

 

5. Carbon Storage in the Seabed

While the other four opportunities can be seized immediately, carbon storage in the ocean seabed needs to be further researched before it can be implemented. The process involves injecting concentrated carbon dioxide deep into the seabed. The panelists warned that carbon storage does have some potential risks that must be acknowledged, but it could be useful for reducing carbon dioxide in the atmosphere.

 

The High Level Panel plans to release a final report by 2020 on the opportunities for a sustainable ocean economy, following the release of a series of blue papers on the topic.

The Because the Ocean Initiative released a similar report, which also called for an increase in blue energy, nature-based solutions, and green shipping. Similarities between the two reports underscore the ocean’s vast potential to help mitigate and adapt to climate change.

 

Authors: Savannah Bertrand & George Davidson