Bizarre new solution to climate crisis involves tropical algae – and a whole lot of poop

It’s good news for the planet – and dairy lovers. Scientists in Sweden have discovered that they can cut greenhouse gas emissions from dairy cows’ manure by almost half – as long as they add algae to it.

The algae, known as red sea plume, is usually found in tropical, warm waters. It is a natural methane inhibitor, blocking the generation of the gas through a compound called bromoform.

And when the researchers added red sea plume to the cow pats, the algae cut down the methane emitted during decomposition by 44 per cent – showing promising results in the battle against climate change.

Around one-third of global emissions of methane – one of the worst greenhouse gases – come from ruminant livestock.

Ruminant animals, such as cattle and goats, have four-chambered stomachs that allow them to digest their food without properly chewing it. Methane is released when these animals burp – but also when their manure decomposes.

It’s been known for some time that the inclusion of algae in cows’ diets can reduce the methane emissions in their burps. The new study instead focuses on what comes out the other end.

Published in Frontiers in Sustainable Food Systems, the research also found that supplementing the cows’ diets with the algae achieved positive results. However, it points out that this isn’t currently an entirely suitable solution for dairy cow emissions.

Red sea plume can increase iodine levels in the milk that dairy cows produce. Iodine is important in the human body, which needs it to produce the thyroid hormones that regulate metabolism and help babies develop during pregnancy.

But too much iodine can cause issues like thyroid problems, and the element is toxic in high concentrations.

These are just early stages in natural methane inhibitors being used on a wide scale. The pilot study involved just four cows – future studies with larger sample sizes are needed to establish the certainty of the results.

As Professor Sam Wilson, biogeochemist at Newcastle University, tellsBBC Science Focus: “We have to remember that 70 to 80 per cent of cows' emissions come from breath, not butt.

“By focusing on what comes out of a cow's behind, this study is focusing on one-third of methane emissions. Two-thirds come from their breath.”

Unfortunately, this solution won’t fix the problem on its own – but shows promising results in the early stages.