Our oceans play a vital role in supporting life on Earth and are powerful allies in the fight against climate change, yet they remain mostly unexplored. Join us as we deep-dive into learning more about The Great Unknown.
In total 71% of the Earth’s surface is covered by water, our home planet is nicknamed The Blue Marble after all. Most of that water is in the oceans — vast systems that influence the climate, weather, ecosystems, and human livelihoods.
It’s quite strange, then, that we still know so little about them. Around 95% of our oceans remain unexplored (!). NASA calls them ‘The Great Unknown’. What we do know, however, is that they’re big, beautiful, a joy to swim in, and hugely important.
“No Water, No Life. No Blue, No Green.” - Sylvia Earle
Supporters of life
It’s thought life began in the oceans around 3.5 billion years ago. Fast forward (a lot) to today and they’re still fundamental to all life on earth.
Whilst rainforests such as the Amazon are often in focus as being keystone ecosystems, removing carbon and pumping out oxygen, between 50-80% of the Earth’s oxygen is produced by marine plants and bacteria. Without them, we’re in trouble.
Oceans also provide food, livelihoods and wellbeing for millions of people around the world and are home to a wonderful array of wildlife, like the ‘glowing’ Hawksbill disco sea turtle.
Cleaning up after us
Our activities emit a lot of carbon, 1.5 trillion tons since the industrial revolution. But, thankfully, not all of it stays in the atmosphere and contributes to global warming.
As well as land ecosystems, a lot of CO2 gets absorbed by the oceans too. It’s thought that between 1994 and 2007 the oceans absorbed 31% of all CO2 emitted by us.
This isn’t good, however, because as atmospheric CO2 levels increase the oceans will dutifully absorb more CO2, which results in acidification and rising surface temperatures, threatening life such as coral reefs.
Natural climate control
As well as CO2, oceans also absorb a lot of the extra heat caused by global warming. In fact, they’re the largest solar energy collectors on earth.
Over the last 200 years, it’s thought that as much as 90% of the extra heat trapped by global warming has been absorbed by the oceans. They also perform an important job redistributing the absorbed heat around the globe, acting like a natural climate control system.
The Great Ocean Conveyor Belt moves hot and cold water around the world, keeping global temperatures balanced. It’s the reason Europe doesn’t freeze over during the winter and the Equator doesn’t boil.
A potentially lucrative clean energy source
Ever stood and watched waves batter against a shoreline? The power is awesome. Now imagine if we could harness it for our own uses.
We’re delighted to see solar and wind power making great headway in recent years, but there’s a lot of potential for ocean energy which hasn’t been utilised yet.
Around the coast of the US alone, it’s estimated that breaking waves could produce almost a third of the amount of electricity the U.S. consumes each year. To quote Kanye West “that’s just the waves, the waves don’t die” (we think he was referring the reliability of wave power).
There are more clever ways we could potentially harvest the ocean’s energy, but we won’t dive into them here.
Resilient to a point
Whilst oceans do so much for us but we continue to pollute them —“is that a plastic bag or a jellyfish?”— and they can only be our allies against climate change for so long. Oceans are remarkably resilient but it’s looking like they might be reaching a tipping point.
It’s predicted that soon they’ll stop being able to absorb CO2 as effectively, so more of what we emit will be left in the atmosphere.
Worryingly, phytoplankton (key oxygen-producing marine plants) numbers are in decline, down about 40% since 1950.
The Great Ocean Conveyor Belt has slowed by around 15% in the last 70 years and scientists believe this is as a result of melting Greenland ice sheets.
We don’t want to get all ‘The Day After Tomorrow’ here but this will likely lead to more extreme weather.
Like with the climate, it’s not too late to save our oceans. Based on recent conservation successes, scientists believe that with a renewed effort it’s possible to restore oceans back to their former glory by 2050.
Key to this is controlled fishing, habitat restoration, and pollution cuts.
Once progress starts in one area it bolsters the rest of the system, for instance increasing marine wildlife populations helps with heat absorption, carbon capture and cleaning.
As individuals, we can help the cause by:
- Reducing our carbon footprint. Here’s a recent study on the best methods of doing that.
- Making sustainable seafood choices. Shellfish, particularly mussels, are a sustainable choice and look out for accreditations such as MSC.
- Using fewer plastic products.