Food Waste Uncovered: following food waste from land to ocean

We often think of food waste as a land-based problem, yet did you know it is an everyday threat to marine life and, ultimately, to us?  

In the greater context and amidst the chaos in the world we live in, climate change remains a persistent issue. With major events leading up to COP30 highlighting not just the challenges, but also the unique solutions to Earth’s – and our own – ongoing battle, one event closer to home has all of us at City Harvest reflecting on the wider impact of our work.  

London Climate Action Week

London Climate Action Week (LCAW) has returned for its seventh year, and I find myself reflecting on the capital’s role as a global climate leader—and the urgent environmental issues that demand our collective attention. With over 45,000 attendees and hundreds of events, LCAW leverages London’s exceptional network of organisations, communities, and individuals to speed up climate action both locally and globally. It’s a great chance to genuinely advocate and unite leaders to address this urgent, life-threatening issue. 

Focusing on an often-overlooked topic, and inspired by World Oceans Day earlier this month, I want to focus on the alarming impact of food waste on our oceans and the shocking persistence of plastic pollution in 2025. 

How Much Food Waste Reaches the Ocean?

In the UK alone the average person throwing away nearly 70kg of food each year. Environmentally, food waste generates an estimated 18 million tonnes of CO₂ emissions per year, accounting for about 8% of the UK’s greenhouse gas emissions. 

According to WRAP while most UK food waste is sent to landfill, incineration, or recycling, a portion still finds its way into rivers and, eventually, the ocean—often via improper disposal, littering, or stormwater runoff. There is no precise figure for how much UK food waste enters the ocean, but with millions of tonnes generated annually and only 1.8 million tonnes recycled, the risk of environmental leakage remains significant. 

What’s the actual impact of food waste in the ocean?

Eutrophication and Dead Zones: Food waste is rich in nutrients like nitrogen and phosphorus. When these nutrients flood into the ocean, they can trigger massive algal blooms—a process called eutrophication. These blooms block sunlight and consume oxygen as they decompose, suffocating marine life and creating “dead zones” where few organisms can survive. The economic and ecological impacts are shocking, affecting fisheries, tourism, and the overall health of marine ecosystems. 

Plastic Pollution: The Persistent Plague 

If food waste weren’t bad enough, it’s often accompanied by plastic packaging—a double blow to the ocean’s health. In 2025, an estimated 8 to 11 million tonnes of plastic will still enter the ocean annually, accounting for about 80% of all marine pollution. This plastic doesn’t disappear; it breaks down into microplastics, which are consumed by plankton and other small organisms at the very base of the food web. 

• Microplastics and Toxins: Microplastics act like sponges, soaking up toxic chemicals from seawater. When marine life ingests these particles, the toxins accumulate in their tissues and move up the food chain—again, eventually reaching humans. The effects ripple throughout the ecosystem, threatening global biodiversity and food security. 

What can we do? 

No single organisation can solve the growing challenges of food waste and environmental degradation alone. But through collaboration, shared responsibility, and community-driven action, we can make a lasting impact.

Here’s how you can help: 

• Reduce food waste: Plan your meals, store food properly, and compost scraps.
• Choose wisely: Opt-in to products with minimal or reusable packaging to reduce plastic waste.
• Get involved, join local climate action or sustainability groups to stay engaged and informed.
• Support impactful initiatives: Back organisations and policies that promote sustainable food systems and reduce food waste, such as City Harvest.  

Food Charity, City Harvest London is at the forefront of tackling the UK’s food waste crisis. We rescue surplus food from retailers, manufacturers, and producers—food that would otherwise be wasted—and redistribute it to charities and community groups supporting people in need. 

In 2025, about 3,007 tonnes of surplus food have been redistributed in the UK, providing nearly 7,160,000 million meals and preventing vast amounts of food from entering the waste stream. By intercepting food before it becomes waste, City Harvest not only helps reduce greenhouse gas emissions but also lessens the risk of food and packaging leakage into waterways and the ocean. You can support City Harvest by:  

• Volunteering to support Londoners in need and the planet.
• Donating money to our mission.

Our efforts directly support climate action, food security, and the health of our marine environments. Every tonne of food rescued is a tonne that doesn’t contribute to pollution, eutrophication, or the plastic crisis in our seas.