The oceans can play a large, pivotal role in global efforts to mitigate and adapt to climate change and avoid the prospective impacts of a 1.5 degree rise in mean global temperature come 2050, according to a report commissioned by the United Nations (UN) Intergovernmental Panel on Climate Change (IPCC) High Level Panel for a Sustainable Ocean Economy— more than all the coal power plants in the world in an average year.
Carrying out ocean-based climate mitigation actions along five strategic lines could reduce global greenhouse gas (GHG) emissions nearly 4 billion metric tons of carbon dioxide equivalent (CO2e) by 2030 and more than 11 billion metric tons by 2050 as compared to business as usual emissions. That would close the so-called "emissions gap" between projected global temperature increases based on current policies and trends continuing and those deemed consistent with capping them by as much as 21 percent that sets them on a pathway that peaks at 1.5, by 2050, according to The Ocean as a Solution to Climate Change: Five Opportunities for Action," which was produced by the World Resources Institute (WRI) released Sept. 23.
Ocean-based Renewable Energy
The report authors lay out the five strategic, ocean-based areas of climate action as follows:
- Ocean-based Renewable Energy
If ocean-based renewable energy technologies — such as offshore wind (using fixed and floating technology), wave, tidal and floating solar — displaced coal-fired power plants, the total mitigation potential for the sector could be equal to taking over 1 billion cars off the road per year. Measures related to project finance and tax regimes will be crucial to promoting investment and support the deployment of offshore wind technologies. For other ocean-based renewable energy technologies, more policy support for research and development is needed to get the benefits of scale, including lower costs, that come with larger commercial plants.
- Ocean-based Transport
Ocean-based transport through international shipping has a powerful role to play. Technical and operational interventions are key to curbing energy consumption in international and domestic shipping and swapping low- and zero-carbon fuels (such as hydrogen, ammonia and some biofuels) for diesel and bunker oil. The technology is ready now, but is being adopted in a limited way due to market barriers and market failures. Addressing these through national government and International Maritime Organization policy will be essential to reducing GHG emissions. There also needs to be development of supply chains and technologies to enable ships to switch to new low- and zero-carbon fuels.
- Coastal and Marine Ecosystems
Nature-based solutions including mangroves, salt marsh and seagrasses that store carbon, and seaweed aquaculture that can be used for fuel, food and feed, offer significant mitigation potential. They also help protect coastal areas from storms and act as nurseries for fish, increasing food security and biodiversity for local communities. In the short term, we need to focus on conserving and protecting these valuable ecosystems to prevent the release of more of the carbon dioxide that is sequestered and stored in their soil. Restoration efforts must also be scaled up as well as research into the potential for seaweed to replace more emissions-intensive options for fuel, feed and food.
- Fisheries and Marine Aquaculture, and Dietary Shifts
Reducing emissions from optimizing wild fisheries, replacing feed in aquaculture and increasing the share of ocean-based protein in human diets, could also play a vital role. Ocean-based proteins are far less carbon-intensive than land-based proteins (especially beef and lamb). Increasing their share in human diets will be essential to help the sector to achieve its mitigation potential. Sustainable growth in seafood production and consumption, particularly from aquaculture, is at the core of these potential benefits. Strategic policy will be required to increase the share of ocean-based food in the human diet.
- Carbon Storage in the Seabed
Storage of carbon in the seabed has enormous theoretical potential to divert carbon from the atmosphere, but it currently faces significant technical, economic and sociopolitical challenges – including concerns about environmental safety — that must be explored before this can be deployed at the necessary scale to realize its mitigation potential.