How Ocean Pollution Fuels the Climate Crisis

Michael Thompson

Welcome back to “Our Oceans are the Solution to Climate Change.” I’m Michael Thompson, and with me are Emily Carter, James Miller, and Charlotte Hughes. Today, we’re diving into how ocean pollution drives the climate crisis—quite literally, it's a bigger deal than most people realize.

Emily Carter

Absolutely, Michael. I think people forget—or never even learn—that the ocean is not just a lovely backdrop for holidays or documentaries, is it? It covers 70% of the Earth’s surface and actually holds about 97% of the planet’s water. That massive size isn’t just a fun fact—it’s vital for regulating the climate. Our seas absorb heat in summer, release it in winter, and have soaked up a whopping 93% of the excess warmth caused by global warming since the 1950s.

James Miller

Yeah, that’s wild. And it’s not just heat. The ocean’s like... I dunno, this ultimate carbon sponge? If we didn’t have it swallowing all that carbon and heat, things on land would be so much worse. But when the ocean warms, it gets deoxygenated, the sea levels creep up, storms whack us harder, and weather patterns start acting all weird. It’s not just coastal towns that pay for it, it’s everyone.

Emily Carter

And I can actually speak to that! Last year, on a coastal survey off Cornwall, we saw these huge jellyfish blooms. Normally, you’d get the odd jelly if you were unlucky, but now, entire stretches looked like underwater minefields. Warmer water makes it ideal for them, but disastrous for other species—they can edge out fish and disrupt the entire local food web. That’s just one tiny knock-on effect from warming seas.

Charlotte Hughes

It’s an excellent example, Emily. The impacts reach far and wide. If you think about it, the changing temperature in the Southern Hemisphere is actually accelerating ice melt, altering ocean currents—just this endless domino effect. Weaken the ocean’s systems, and we jeopardize their ability to store carbon and produce oxygen, both of which are absolutely core to climate stability.

James Miller

We’ve got to talk about sewage. I know, not the sexiest topic, but it’s a massive player in this whole thing. Something like 80% of the world’s sewage ends up in the ocean untreated. That’s mostly from just 25 really bad-offending watersheds—those alone are dumping about half the world’s nitrogen and pathogen pollution. That’s... kind of horrifying.

Michael Thompson

Yeah, it’s staggering. When I was doing a research trip in the Pacific—this was, I think, about four years ago—there was this coastal village that caught my attention. The fishermen told us the fish just weren’t showing up like they used to, and you could physically see this kind of murky, oxygen-poor water hugging the shore. These are hypoxic zones—dead zones, basically. The culprit? Pretty much entirely untreated sewage and fertilizer runoff.

Emily Carter

Which links directly back to those algal blooms we keep reading about, doesn’t it? Too many nutrients in the water means toxic algae take over, block sunlight, and then die off in such huge numbers, they use up all the oxygen as they decompose. Nothing else can survive in that water. The Gulf of Mexico dead zone is infamous for this, but we’re seeing it pop up everywhere, from Australia’s reefs to estuaries around the world.

James Miller

And when those marine food webs collapse? There goes a huge source of carbon capture, global protein, and whole economies that depend on the sea. It’s wild that we treat the ocean like this bottomless waste basket, expecting it to just soak up our mess without consequences.

Charlotte Hughes

That’s right, and it’s a problem of both infrastructure and priorities. In both developed and developing countries, outdated sewer systems regularly overflow. All of that gets flushed, quite literally, into rivers and seas, multiplying these issues globally.

Charlotte Hughes

So here’s where things get a bit, well, bureaucratic. In 2023, the world finally signed a new United Nations High Seas Treaty. It’s designed to make countries assess marine impacts, and it could, in theory, help protect up to 30% of the ocean by 2030. But the legal gaps are huge, especially when we talk about waters close to a country’s coast—their Exclusive Economic Zones. It’s even trickier with regulations around waste dumping from international shipping.

Emily Carter

And big shipping companies still dump untreated sewage outside of twelve nautical miles, which is just... ridiculous. But some countries are coming up with creative answers. In Australia, for example, biosolids from properly treated sewage are actually being used as fertilizer. The North Head facility turns waste into biosolids for growing crops like wheat—it’s a circular solution that takes pollution and literally turns it into food.

Michael Thompson

Those advanced recycling programs are essential, because if we shift to treating sewage as a resource, not just a liability, it helps break this endless loop of pollution. But the problem is scale: most countries just don’t have either the funding or the unified policies to follow through, especially when the benefits cross borders but the costs don’t.

Charlotte Hughes

Yeah, I remember attending these policy sessions in Brussels last year—you’d think everyone would be on the same page, wanting to clean things up. But things kept stalling over who should foot the bill. The ocean might be shared, but financial responsibility is very much not. Until there’s an international framework with teeth, these gaps are going to keep tripping us up.

James Miller

And all of that just emphasizes how innovation—like biosolids, better wastewater treatment, or stricter shipping rules—is only half the answer. We need governments who’ll step up and actually implement, not just talk.

Emily Carter

So, let’s talk solutions—because we can’t just dwell on the doom and gloom. There’s genuinely exciting stuff out there. Artificial reefs, for instance, can help rebuild broken undersea habitats and supercharge marine biodiversity. Bioremediation—using specific plants or bacteria to clean up polluted waters—might sound a bit sci-fi, but it’s working in pilot projects right now.

Michael Thompson

And if we want those programs to actually take off, countries need funding, right? International investment and incentive programs could help developing nations switch to more sustainable waste management. If we reduce the flow of nutrients and chemicals into the sea, we give underwater ecosystems a real shot at recovery—and keep those natural carbon sinks working at full speed.

James Miller

Don’t forget the power of citizen science, either! I’m always amazed at what communities can pull off—local monitoring of pollution hotspots, beach cleanups, all the way up to pushing their governments for stronger regulations. It’s such a simple thing, but data from volunteers has flagged issues that might have flown under the radar for years.

Charlotte Hughes

Completely agree. Policymakers can’t fix what they don’t know about, so grassroots action—whether it's tracking, reporting, or advocating—genuinely matters. It creates pressure, offers invaluable evidence, and ensures coastal communities have a real voice in protecting their own environment. That’s key for meaningful progress.

Michael Thompson

So, what’s the big takeaway here? Ocean resilience isn’t just about throwing money at cool science projects. It’s about policy—real, enforceable cooperation between nations, with the ocean right at the heart of climate plans, not an afterthought. The only way to ensure shared responsibility is to embed ocean health metrics right into national climate strategies.

Emily Carter

And that means everyone—from the U.N. to your local council—needs to prioritize marine conservation in all the big climate decisions. Imagine if every climate policy had to account for dead zones or coral bleaching before it was approved. It’d transform how we tackle both pollution and climate change at the same time.

Charlotte Hughes

There’s also a clear role for community-led projects, like sustainable fishing or local marine protected areas. They’re proof that solutions don’t have to come top-down. When given tools and funding, ordinary people can—quite literally—reshape coastlines and help restore balance. That’s resilience built from the ground up.

James Miller

Totally—none of this happens without public pressure and action. If you’re listening and wondering what you can do, supporting organizations like Our Oceans Incorporated or even just spreading the word, that does matter. Climate action—and ocean protection—need everyone in, not just the experts.

Michael Thompson

Couldn’t agree more. Thanks for joining us today—Emily, James, Charlotte, always a pleasure. And to everyone listening, let’s keep ocean health front of mind. We’re all in this together, and we’ll be back with more insights and solutions soon.

Emily Carter

Thanks so much, Michael. Cheers, everyone—take care and do something positive for the oceans this week!

James Miller

See ya, guys! And yeah, keep the pressure up—it really does add up.

Charlotte Hughes

Goodbye, all. Let’s keep our oceans healthy—until next time!