International Compost Awareness Week 101

This week is International Compost Awareness Week (ICAW)! ICAW is celebrated globally every year during the first full week of May and aims to raise awareness about the benefits of composting and inspire individuals and organisations to take action. It is the largest and most comprehensive education initiative in the compost industry.

ICAW serves as a platform for educators, policymakers, businesses, and communities to come together to share information, resources, and best practices related to all types of composting. The Compost Research and Education Foundation (CREF) has resources available for those looking to get involved including a Celebrate ICAW Manual and an event page.

Each year, the International Compost Alliance (ICA), which includes compost associations from around the world, selects one of the United Nations Sustainable Development Goals (SDGs) to inspire a theme. This year’s theme, ‘Compost … Nature’s Climate Champion!’ reflects the UN’s SDG 13 to “take urgent action to combat climate change and its impacts.” The theme highlights the role compost plays in fighting climate change by improving soil health and reducing waste.

Soil is usually the ultimate destination of most compost and digestate in the UK. Soil is a vital resource that provides many essential services and serves as the source of 95% of our food production. In England and Wales nearly four million hectares of soil are at the risk of compaction and over two million hectares at risk of erosion. Intensive agriculture has caused arable soils to lose 40 to 60% of their organic carbon. Compaction and the loss of organic carbon are serious threats to soils' health. They affect our ability to produce food and reduce our resilience to climate change.

It is essential we do all we can to protect our soils and restore them where we can. That is why compost is so important. Compost enriches soils by providing essential nutrients, improving soil structure, and promoting microbial activity. The nutrients provided by compost significantly reduce the need for chemical fertilisers which are associated with waterway pollution, air pollution, soil acidification, and mineral depletion. Compost also bolsters soil structure by enhancing soil porosity allowing for better air and water circulation, reducing compaction.

In addition to protecting and restoring soil health, composting is a key tool in sequestering carbon. Composting returns the organic matter found in food and garden waste back to the soil, where it becomes a stable component of soil organic carbon. Studies have shown that over a period of four to twelve years, eleven to forty-five percent of the organic carbon applied to soil as compost remained as soil organic carbon. In the UK, our soils currently store around ten billion tonnes of carbon, roughly equal to eighty years of the UK’s annual greenhouse gas emissions. Alongside the carbon storage benefits, increases in organic matter can improve water retention in the soil and make it more resilient to drought conditions and erosion.

The process of composting also has many benefits. The main alternative to composting organic waste is landfill or incineration. According to Defra, the UK sent 6.8 million tonnes of biodegradable municipal waste to landfill in 2021. For every 1,000 tonnes of organic waste, 34 metric tonnes of methane emissions are released. Methane as a greenhouse gas is 25 times as powerful as carbon dioxide and is a primary contributor to global warming. Composting offers a crucial, natural alternative that returns nutrients and carbon back to the soil. Recycling organic waste, via composting or anaerobic digestion, could reduce the use of landfill and incineration by at least one third.

Whatever your role, this week is a brilliant opportunity to make a positive impact. By helping to promote and advocate for composting and the use of compost you can contribute to soil health, carbon capture, and waste reduction efforts. Spread the word about the power of compost!