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Delivering dairy that doesn’t cost the earth


From reducing cow burps with red seaweed to heating homes with manure, Unilever’s Sustainable Sourcing Manager for Dairy, Klaas Jan van Calker, explains how we’re working to cut emissions in the dairy sector.

Illustration of a smiling mouth biting into a Magnum ice cream
Klaas Jan van Calker, Unilever’s Sustainable Sourcing Manager for Dairy
Klaas Jan van Calker, Unilever’s Sustainable Sourcing Manager for Dairy

At Unilever, our Climate Transition Action Plan (PDF 7.98 MB) sets out the steps we will take to halve the greenhouse gas emissions impact of our products, per consumer use by 2030, and to achieve net zero across our value chain by 2039.

In a series of interviews, Unilever is introducing some of the many people helping to deliver our action plan and making change happen. Unilever’s Sustainable Sourcing Manager for Dairy, Klaas Jan van Calker explains how lowering emissions from our dairy supply chain will be an integral part of our climate work.

What does your job involve?

I work in our Business Operations Sustainability team, and I’m responsible for sustainable sourcing for dairy. That means developing and implementing a strategy to supply ingredients that go into products across Nutrition and Ice Cream, with a focus on regenerative agriculture and decarbonisation.

Alongside this, I also help to run my family’s own dairy farm, working with my partner and her brother. Having seen a very clear link between regenerative agricultural practices and decarbonisation in my work at Unilever, we are now testing out this same approach on our own farm.

Why is climate action across the dairy sector so important?

The production of milk and dairy creates significant emissions of greenhouse gases, such as methane and nitrous oxide. If you look into the ingredients that contribute to Unilever’s overall footprint, then dairy is significant, especially in ice cream. We know reducing those emissions must be a key part of Unilever’s solution for tackling climate change, and we are already working to do so.

What is the biggest cause of emissions on dairy farms?

It’s the cows themselves. They have four stomachs, the biggest being the rumen, so they can digest fibre-rich feed which we cannot, like grass. But the rumen has some negative side effects, namely enteric methane emissions, which they burp and breathe out during the day. Around 90% of the methane emissions from dairy cows comes through the mouth of the cow and around 10% comes from the manure.

What can we do about this?

There is a lot we can do to manage this. We’ve been monitoring emissions from some of our farms over the last decade and we can see that there is a lot of variation between them. The best farms are usually performing 30–40% better than the average dairy farm, because they are efficient and organised, with well-managed grazing practices.

We’re encouraging this by promoting regenerative agricultural practices, which help to store carbon, maintain healthy soils, and improve water and air quality We’re also looking at ways of adapting cow diets and managing their manure more effectively.

What are going to be the biggest priorities?

I think in the short term we need to look at feed additives, such as red seaweed, because they can really help bring down methane emissions quickly. We’ve already tested a feed additive in the US that potentially lowers methane emissions from the rumen by 60%, and another in the Netherlands that achieved a 30% reduction.

The other key aspect will be really focusing on regenerative agriculture, using different management measures to create an impact on soil, climate, water, biodiversity and livelihoods. Adding new herbs and clovers in your grassland and better grassland management such as focusing on long-term permanent grassland can help to capture carbon into the soil.

We developed the Unilever Regenerative Agriculture Principles (PDF 8.34 MB) to help guide our suppliers on this. The principles enable local communities to protect and improve their environment, while still producing sufficient yields to meet existing and future needs. At the same time, we need to see change at a system level, and so we’re asking governments to redirect environmentally harmful subsidies and invest in supporting regenerative agriculture instead.

6 billionpeople regularly consume liquid milk or other dairy products.

What technological innovations are we exploring?

We’re looking into how we can digest manure and harvest the methane as a renewable source of energy. We already have a few examples of farms working with us in the Netherlands on this – two with manure digesters and one where they are producing electricity from the manure. They are not only creating a stream of renewable energy, but during electricity production they are also generating heat, which is being transferred to 12 local houses and replacing natural gas from the grid.

We’re also exploring other technological options through Ben & Jerry’s Caring Dairy programme, using pilot projects to assess the cost and revenues for each measure per tonne of carbon saved. We’re sharing the learnings with our other brands, so that we can have a scalable approach for reducing our overall carbon footprint.

What do you see as our greatest achievements so far?

Since 2015, we have already seen an emissions reduction of 14% in the pilots run with Ben and Jerry’s. That’s quite a significant reduction but we know there is more we can do. What’s really great is that we’ve got the enthusiasm of the dairy farmers behind us on this – they want to be part of the solution and they really want to make these improvements work.

What do you love about your job?

I like the fact that we always try to have a holistic view. We’re asking ourselves what the future of food systems look like and about the position of livestock in that system. As a part-time dairy farmer myself, this is important to me.

In principle, what we want to achieve is for dairy farming, as well as other livestock farming, to shift in such a way it’s not only not competing with plant-based food which can be consumed by humans, but instead it’s actually supporting plant-based food production, by using land that cannot be used for arable or vegetable crops, like marginal grasslands for grazing.

We want the sector to use the by-products of the food industry, like brewery grains, sugar beet pulp and other waste streams, to feed cows and other animals. In return, you have the manure coming back to these fields as fertiliser so actually livestock is contributing to a healthy plant-based food system.

Already, you can see the progress being made with farmers, with suppliers, with new technologies. I think we are showing that big improvements are within reach of our sector.

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