· 6 min read
Image credit | Getty
Big oil spills generally make front-page news. But there is much more happening across the ocean that critically threatens the health of our seas. Warming waters, acidification and pollution are seriously impairing ocean biodiversity.
About 71% of the Earth’s surface is water-covered, with oceans holding about 96.5% of it. “The oceans are the primary regulator of the climate and the life support system for the entire planet. Humanity cannot survive without a healthy marine ecosystem,” says marine biologist Dr Howard Dryden.
While threats to maritime assets are scrutinised, the wellbeing of the oceans and how those assets impact them is often overlooked. Like aviation, shipping is not covered by the Paris Agreement. Of all the UN Sustainable Development Goals, SDG 14 – ‘Life Below Water’ – is the least funded. Insurers must step in.
Warming also contributes to the thinning of ice shelves and sea ice, which affects Earth’s climate system, particularly the Atlantic Meridional Overturning Current (AMOC).
Marine ecosystems and human livelihoods are under threat. For instance, warm waters harm corals, along with the marine life they support – and ultimately, the people who depend on them. More than 90% of the warming on Earth in the past 50 years has happened in the ocean, according to NOAA. It is vital to limit shipping’s adverse impact before we reach the point of no return.
Evil twin
The International Environment Forum (IEF) calls ocean acidification the “evil twin” of the climate crisis. It occurs when the ocean absorbs carbon dioxide, reducing the pH levels of seawater. As pH drops, calcifying species like corals, oysters and sea butterflies struggle to maintain their shells, leading to slower growth and decreased survival.
Until recently, ocean acidification had not crossed its planetary boundary. But a new study by Plymouth Marine Laboratory (PML), NOAA and Oregon State University confirms that it now has.
“It’s a ticking timebomb for marine ecosystems and coastal economies,” says PML’s professor Steve Widdicombe, who is also co-chair of the Global Ocean Acidification Observing Network.
Image credit | iStock
Unsustainable blue economy
“Imagine six million tonnes of plastic entering the oceans annually and 20 million tonnes of partially combusted carbon from the shipping industry alone,” says Dr Dryden. “Carbon contains toxic heavy metals and hydrocarbons. It is as toxic as plastic and there are three to four times more of it.”
International shipping produces nearly a billion tonnes of CO2 emissions – 2% to 3% of the global total. “This must be halved by 2050 to avoid dangerous climate change,” warns Tristan Smith of UCL Energy Institute.
“We could survive climate change; we will not survive the loss of marine life and the ocean drifters that life on Earth depends on,” warns Dr Dryden.
Ships scrub flue gases and dump the waste into the sea – often unfiltered – creating pollution out of sight and reach. “Nearly every vessel, from commercial vessels to yachts, is releasing toxic metals into the sea,” says Dr Gordon Watson of the University of Portsmouth. “Toxic metals from shipping are a hidden threat to healthy seas and nobody's really talking about it.”
He calls for legislation to put shipping at the heart of sustainable ocean policies.
If shipping were a country, it would be the sixth-largest CO2 emitter. “The world has focused on carbon but marine biodiversity also regulates the climate,” notes Dryden.
“The world has focused on carbon mitigation as the only solution for climate change,” continues Dryden, who recently published a discussion paper describing the factors that control marine biodiversity and how it regulates planetary climate.
Deep-sea mining is among the most controversial threats to ocean health. Evidence shows it can cause long-lasting damage to fragile ecosystems. One experimental site off the US East Coast, mined over 50 years ago, still shows little sign of recovery, according to the BBC.
“Seabed mining could become one of the defining environmental battles of 2025,” says Myra Williamson, senior lecturer in law at Auckland University of Technology, writing in The Conversation. “Governments are currently deciding whether to allow mining of the ocean floor for metal ores and minerals.”
Disappointingly, the final declaration from the recent UN Ocean Conference (UNOC) in France fails to call for a precautionary approach or a ban on deep seabed mining.
Each UNOC ends with declarations. Yet in the last eight years, plastic pollution has surged, coral reefs have been bleached, whales have been harpooned, fish stocks have crashed and sea temperatures have spiked. “We gather, we speak, we applaud, but the ocean keeps dying,” laments ocean campaigner Luke McMillan.
Ocean heat trends (1993-2024)
Change in stored heat content in the upper 2,000 meters (1.2 miles) of the ocean from 1993-2024. Darkest orange areas show where heat content increased by six or more watts per square meter. Some areas have lost heat (blue), but not enough to offset increases everywhere else. Changes in grey shaded areas were not statistically significant, meaning small relative to the range of natural variability.
Source: NOAA Climate.gov, based on data from John Lyman
Poseidon Principles
The Poseidon Principles offer a global framework for assessing and disclosing the climate alignment of financial institutions’ shipping portfolios. They aim to create a common baseline for measuring whether portfolios align with climate goals.
Currently, 35 institutions have signed up – covering more than 80% of the global ship finance portfolio by bank loan value.
The Poseidon Principles for Marine Insurance – launched in December 2021 – extend this framework to insurers’ hull and machinery portfolios. But take-up remains limited. Is it too little, too late?
Ship strikes are among the leading causes of human-induced whale mortality, killing 20 times more whales than whaling, according to SevenSeas Media. Underwater noise from ships is also a significant threat, according to WWF.
Global shipping traffic has increased by 300% in the past two decades. Vessels have grown larger and faster. Today’s merchant fleet is the biggest contributor to underwater background noise, which has doubled each decade in the last 50 years.
Cetacean conservationist Ed Goodall highlights new research in Nature Communications showing how vital whales are to ocean ecosystem health and resilience.
Healthy ecosystems need their full range of wild animals, at natural baseline levels, to function optimally. “It’s one of our best tools to tackle the climate crisis,” says Goodall.
The fishing method of bottom trawling is also hugely destructive, dragging heavy nets across the seabed, indiscriminately catching marine life and destroying habitats, explains Greenpeace.
Illegal, unreported and unregulated fishing is another major threat, conducted in the shadows and undermining ecosystems, food stocks and fragile coastal economies. Cutting off access to insurance is a key deterrent, according to the Council on Foreign Relations.
“After almost 100 years on the planet,” reflects Sir David Attenborough, “I now understand the most important place on Earth is not on land – but at sea.”
Can marine insurers live up to this challenge?
This article is also published on The Journal. illuminem Voices is a democratic space presenting the thoughts and opinions of leading Sustainability & Energy writers, their opinions do not necessarily represent those of illuminem.
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