• The ocean is a massive carbon sink, protecting us from the worst of climate change.
  • But rising air temperatures are melting glaciers, while warming seas are bleaching coral.
  • Action like coral reef restoration is already underway - and research has found some corals to be more resistant to higher temperatures.
  • And there are now calls to designate Marine Protected Areas for 30% of the ocean by 2030.

The ocean is inextricably linked to our climate. Rising air temperatures due to global warming are melting the polar ice caps and dissolving glaciers, leading to rising sea levels.

But the ocean is also playing a crucial role in protecting us from the worst effects of climate change. Scientists say the seas have absorbed 90% of all the warming that has taken place in the past 50 years.

On the rise

The Intergovernmental Panel on Climate Change (IPCC) says that by 2100, sea levels will be between 0.26 metre and 0.77 metres higher than today. It’s estimated that by 2100, rising sea levels will threaten 200 million people who live in low-lying coastal areas.

a map sowing where people will be most affected by rising sea levels
By 2100, sea levels will be between 0.26 metre and 0.77 metres higher than today.
Image: Statista

Researchers say that almost half of the world’s sandy beaches could disappear as sea levels rise. It’s estimated that by 2050, more than 570 cities will be affected by a sea level rise of 0.5 metres.

Warming seas

a chart showing Sea temperatures since 1880.
Sea temperatures since 1880.
Image: IUCN

Rising sea temperatures are to blame for “coral bleaching”. When the water is too warm the corals expel the algae living in their tissues and turn white. Scientists say that coral can recover from bleaching events but it is permanently weakened.

a picture of fish in coral
Coral reefs have the highest biodiversity on the planet, even greater than rainforests.
Image: Pixabay/lpittman

Our changing waters

Meanwhile, melting freshwater from the world’s polar ice sheets changes the chemical composition of the sea making it hard for some species to survive. A study of the Baltic Sea warned that reducing salinity could threaten zooplankton, the tiny creatures who represent the foundation of the marine food chain.

Freshwater also changes ocean currents and if these fail or change course it can lead to oxygen-depleted “dead zones” where marine animals and plants cannot survive.

The oceans are our biggest carbon sink, absorbing around one-third of the CO2 emitted by human activity since the start of the Industrial Revolution.

Adding CO2 to seawater in these quantities acidifies the oceans and this is affecting many marine species, especially clams, mussels and sea snails which are unable to grow their shells in acidified waters.

a chart showing  How climate change impacts our ocean.
How climate change impacts our ocean.
Image: IUCN

Coral research is making waves

Conservationists and community groups are taking action to restore their coral reefs. In Jamaica, which lost 85% of its coral to hurricanes and pollution, “coral gardeners” are nurturing young corals.

There’s hope, even, for the Great Barrier Reef in Australia, where scientists have developed a process they call “coral IVF” in which they collect coral sperm and eggs and grow new young corals which are then implanted in areas that have been bleached. They say the results are promising.

Meanwhile, corals in the Red Sea have been found to keep their colour, showing resistance to higher temperatures. Scientists conducting a genetic analysis on coral samples in the Gulf of Aqaba found those corals, and the algae and bacteria they live in symbiosis with, can withstand average temperatures 5°C higher than what they typically experience. It means they can identify 'super coral' that can withstand heat stress.

Towards sustainability

The carbon sequestration that the ocean provides will be vital if we are to slow the rate of global warming, says the International Union for Conservation of Nature (IUCN) which has called for 30% of the ocean to be designated as Marine Protected Areas (MPAs) by 2030.

Fishing and tourism needs to become more sustainable and coastal development needs to be controlled to prevent marine environments being harmed, says the IUCN. It adds tht research must continue so new measures can be developed as the damage to our seas becomes more obvious.

What's the World Economic Forum doing about the ocean?

Our ocean covers 70% of the world’s surface and accounts for 80% of the planet’s biodiversity. We can't have a healthy future without a healthy ocean - but it's more vulnerable than ever because of climate change and pollution.

Tackling the grave threats to our ocean means working with leaders across sectors, from business to government to academia.

The World Economic Forum, in collaboration with the World Resources Institute, convenes the Friends of Ocean Action, a coalition of leaders working together to protect the seas. From a programme with the Indonesian government to cut plastic waste entering the sea to a global plan to track illegal fishing, the Friends are pushing for new solutions.

Climate change is an inextricable part of the threat to our oceans, with rising temperatures and acidification disrupting fragile ecosystems. The Forum runs a number of initiatives to support the shift to a low-carbon economy, including hosting the Alliance of CEO Climate Leaders, who have cut emissions in their companies by 9%.

Is your organization interested in working with the World Economic Forum? Find out more here.

Power to regenerate

The World Economic Forum has convened the Friends of Ocean Action, a group of 65 global leaders from business, civil society, international organizations, science and technology committed to fast-tracking solutions to the damage caused to our seas by climate change.

“We have the knowledge, power and technology to put the ocean on a path to recovery,” says the Friends’ mission statement. “The ocean’s power of regeneration is remarkable, if we just offer it the chance.”

Meanwhile, on 25-26 May, the Forum’s Virtual Ocean Dialogues event aims to encourage practical dialogue on the global ocean action agenda.

The Forum’s Uplink innovation crowdsourcing platform is also bringing environmental entrepreneurs together to share their innovations to save and protect the ocean, ranging from zero-carbon shipping to the restoration of coral reefs.