The vast blue ocean is an excellent ally against climate change because it has a superpower: It absorbs CO2 from the atmosphere. However, it is often neglected. Without protection and restoration, the ocean won’t be able to assist in slowing down greenhouse warming effectively. With floods, wildfires, droughts, and melting ice sheets being reported worldwide, now is the time to advocate for blue.
The Ocean – The Blue Climate Change Ally
The first section of The IPCC’s (Intergovernmental Panel on Climate Change) Sixth Assessment, published on August 9th, highlighted that it is “indisputable that human activities are causing climate change, and that it is “widespread, rapid, and intensifying”.
The IPCC report sounds alarms and calls attention to the pressing necessity of reaching net-zero by 2050 to avert catastrophic scenarios, confirming what scientists have been saying for years.
Projections in the report show that under scenarios of increasing CO2 emissions, the ocean is expected to lose its ability to absorb CO2, resulting in a more significant amount of emissions remaining in the atmosphere.
According to the report, every 0.5 degrees Celcius causes “discernable increases in the intensity and frequency of hot extremes”. Although some impacts of climate change are irreversible in our lifetime, it is possible to reverse the trend and prevent the world temperature from changing beyond 1.5 degrees Celcius.
To reverse the trend, global emissions need to be halved by 2030 to reach net-zero by 2050 – mainly by shifting reliance on fossil fuels to renewable energy. Along with phasing out sources of emissions, a reduction in CO2 in the atmosphere is also required.
Recently the US Special Presidential Envoy for Climate, John Kerry, tweeted: “Life is about making choices, and we’re facing the biggest one yet. The IPCC report clarifies that our window is narrowing, but it’s not too late to act. We must choose to earnestly respond to the climate crisis while we still can.”
The Ocean as a Carbon Sink
Each year, the Earth’s surface is responsible for reducing billions of tonnes of CO2 in the atmosphere through natural carbon capture. Trees are well-known for removing CO2 from the atmosphere.
However, carbon sequestration is not exclusive to the terrestrial world. Coastal ecosystems store more carbon per unit area than forests. According to the Environment Justice Foundation (EJF) report, the ocean absorbs one-third of the CO2 pumped into the atmosphere.
It does this by sequestering carbon in living plants and marine animals, sinking it to the deep sea, where it remains for hundreds of years. The carbon stored in marine ecosystems is known as “blue carbon”. The ocean contains 49 times the amount of carbon as is in the atmosphere.
The EJF report cited research stating mangroves store up to four times more carbon per hectre than tropical forests, and seagrass meadows store nearly 20 gigatonnes of carbon.
The Ocean’s Kryptonite: Exploitation
Dr Carlos Duarte, an ecologist listed on Reuter’s Hot List: The World’s Most Influential Climate Scientists, said: “Seagrass is an unsung hero in the fight against climate change. But disease, dredging and the deterioration of our ocean’s water quality threaten to wipe out this vital species – unless we take immediate action to protect it,” in session 4 of TEDMonterey 2021.
According to King Abdullah University of Science and Technology (KAUST), in the northwest of Saudi Arabia, coastal development, aquaculture – shrimp farming in particular and toxic wastewater from industrial activities have reduced seagrass and mangrove ecosystems significantly.
Sea level rise and a warming ocean due to climate change are also detrimental to seagrass.
In the open sea, great whales sequester millions of tonnes of carbon. They accumulate carbon in their bodies during their long lives. When they die, they sink to the bottom of the ocean burying around 33 tonnes of CO2 each, removing it from the atmosphere for centuries.
Although more than half of the biological carbon capture is stored by marine life, the biodiversity in the oceans is under threat.
Overfishing has depleted fish stocks, impacting ecosystems that play an integral role in sinking carbon. As stated by the World Bank, almost 90 per cent of global marine fish stocks are fully exploited or overfished.
Advocating for Ocean Policies
A letter accompanying the EJF report signed by advocates and scientists urges governments to take action in the run-up to COP 26 in Glasgow in November.
It implores leaders to do the following:
- To protect 30% of the ocean by 2030
The ocean covers 70% of the world’s surface, yet only 2.7% is highly protected. Marine Protected Areas (MPAs) limit human activities, like fishing, underwater drilling and sports. MPAs help counteract issues such as habitat destruction and overfishing.
- To include legally binding targets to protect and restore blue carbon environments in updated Nationally Determined Contributions (NDCs) plans.
NDCs are at the centre of the Paris Agreement. They are a country’s self-determined plans to mitigate the climate crisis, which countries are obliged to submit; however, they are non-binding.
- To agree on an international moratorium on deep-sea mining
Declining terrestrial resources and an increased interest in green tech has stimulated attraction for mining for metals like cobalt, lithium, manganese, making deep-sea mining imminent.
Despite green tech being crucial for a net-zero world, there is insufficient research on how best to extract from the deep sea without disturbing ecosystems and potentially releasing CO2 stored in sediments. Some scientists say there needs to be a more considerable reliance on reusing and recycling metals from discarded devices.
All the evidence suggests that the ocean is a tremendous blue carbon shield against the impending dangers of climate change. Its protection should be at the heart of climate policy.
You can add your voice to the EJF letter here.
Contributed by Suzanna Hayek
Suzanna is an MA Journalism student interning at Irish Tech News. She is passionate about giving the ocean a voice in the urban world.
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