Our oceans in crisis

There is another resounding reason for urgently moving away from fossil fuels: to save our oceans.

Burning fossil fuels is having a grave impact on our oceans that’s only just starting to be understood.

A study released earlier this month from the International Programme on the State of the Ocean (IPSO) has shown that our oceans are in such a bad way that a mass extinction may already be under way.

The “deadly trio”

IPSO’s report warns of a "deadly trio" of acidification, oxygen loss and ocean warming:

1. Ocean acidification

The oceans currently absorb about a third of human-created CO2 emissions, roughly 22 million tons a day. This has benefited us by slowing the climate change these emissions would have instigated if they had remained in the air.

But when carbon dioxide dissolves in the ocean, carbonic acid is formed. This means that the oceans become more acidic.

Acidification threatens marine organisms that use calcium carbonate to build their skeletons, such as reef-forming corals, crabs, oysters and some plankton vital to marine food webs.

Alarmingly, IPSO’s recent study has said that the rate of acidification in the oceans is the highest it’s been in over 300 million years due to carbon dioxide emissions from burning fossil fuels.

Moreover, it is acknowledged by the scientific community that the damage being done now will take hundreds of thousands of years to repair itself through natural processes, so there is no prospect of quick reversal.

2.      The de-oxygenation of our oceans

Our oceans are also running out of air (being ‘deoxygenated’) due to increased temperatures from global warming and runoff from sewerage and agriculture.

The reduction of oxygen is a concern as areas of severe depletion effectively become dead.

3.      Ocean warming

Our oceans are warming because of heat from a build-up of greenhouse gases in the atmosphere.

This is already causing biodiversity to drop and species to scatter away from their natural habitats.

4.      Other human-made stresses

The “deadly trio” of threats to our oceans are “further exacerbated by other anthropogenic stresses” like pollution, overfishing, habitat destruction, and the introduction of non-indigenous species to different areas.

How much danger are our oceans in?

According to IPSO’s recent study, our oceans are now facing devastating issues at a scale and rate "unprecedented in Earth's known history."

Current rates of carbon release into the oceans are 10 times faster than the rates of release just before the most recent major species extinction about 55 million years ago, the scientists found.

The report went on to say that a mass extinction of key species may already be almost inevitable.

How does the health of the oceans impact us?

Simply put, our oceans are the lifeblood of the world. The potential impacts of this crisis are diverse and enormous.

Our oceans cover nearly three quarters of the Earth's surface, provide about half the oxygen we breathe and feed billions of people every year.

Coral reefs, which are especially in danger, serve as the home for many forms of ocean life. Their disappearance would be akin to rainforests being wiped out worldwide. Such losses would reverberate throughout the marine environment.

Alex Rogers, IPSO’s director and professor of biology at Oxford University, has said:

“The situation should be of the gravest concern to everyone since everyone will be affected by changes in the ability of the ocean to support life on Earth."

What should we be doing about this?

We need to reduce our CO2 emissions – and quickly.

IPSO’s report urged world governments to take fast action to ensure temperatures don’t rise past 2 degrees C. Current limits, it warned, weren’t enough to ensure the health of coral reefs, since there will be a time lag of several decades between a decrease in levels of atmospheric CO2 and the levels of dissolved CO2 in the ocean.

There are other strategies we should adopt too. Evidence suggests that coral reefs in protected ocean reserves are less affected by global threats such as global warming and ocean acidification. This is a big incentive to:

• Create marine protected areas (essentially national parks for the sea) and
• Stop destructive fishing practices.

Let’s get on with it!

No one is disputing that our oceans are in grave danger. Nor are they disputing the urgency of the situation.

There's no time to waste. It's time to take action. 

Image attribution: Milan Boers