Climate change – implications for dairy farming

Weather always brings challenges for the farming community, but climate change has the potential to create additional risks. The dairy and agricultural sectors produce about half of New Zealand’s greenhouse gas emissions, and they are working on ways to reduce them.

Dairy – a significant part of Aotearoa’s economy

Farming is a way of life in Aotearoa New Zealand, and it has shaped who we are as a nation. Our moderate climate and reliable rainfall have enabled good growing conditions. This is one of the few places in the world where cows can graze on pasture year round.

The dairy sector contributes over $19 billion dollars to Aotearoa New Zealand’s economy. In 2019, New Zealand was the main exporter of milk and milk products worldwide. Not all milk products go overseas – Kiwis have one of the highest rates of domestic milk consumption in the world!

Primary industries like dairying require unique sets of environmental conditions for optimum production. If these conditions are disrupted by climate change, the dairy producers and the communities that support them and who they support will also be impacted.

Farmers are at the mercy of the weather, so if climate change is making things more unpredictable, that makes it harder for farmers to plan and prepare.

Ben Fisher, Farm Manager, Scott Farm

Risks posed by climate change

Perhaps the biggest risk for dairy farming is the increased severity of extreme weather events. The right amount of rainfall – at the right times – is important for optimal pasture management.

Too much rain can cause a variety of problems such as:

• loss of soil to erosion
• increased sediment in waterways
• loss of soil structure due to pugging
• increased nitrous oxide emissions from saturated soils
• damage to infrastructure such as fences, bridges and roads.

Not enough rainfall over a period of time can cause drought conditions, which can impact pasture growth and reduce the amount and quality of feed. Farmers need to buy supplemental feed to keep milk production going or dry off (stop milking) stock earlier than planned.

Animal welfare may also be impacted by climate change. Much of the country’s livestock lives outdoors so they risk exposure to extreme weather and/or rising temperatures. Farmers may need to build infrastructure to house animals when necessary or select breeds that better suit the changing conditions.

Pasture plant species are also suited to particular conditions. Changes in temperature and rainfall may require new forage cultivars. Changes may even make some land unsuitable for dairy farming.

There are biosecurity risks associated with climate change. Warmer temperatures may allow new exotic pests, weeds and diseases to become established.

Impacts of dairy farming on climate change

Nearly half of New Zealand’s greenhouse gases come from agriculture. The main gases are methane and nitrous oxide. Methane is produced by ruminant animals and emitted mostly as burps. Methane production is split about evenly between the dairy sector and the beef and sheep sectors. Nitrous oxide is produced by soil microbes that transform nitrogen from urine, dung and fertiliser into a gas.

The dairy sector recognises that climate change is a global issue and, like any large industry, it has to play its part in reducing emissions. Scientists and farmers are involved in a wide range of research to investigate alternative forages, animal breeding and on-farm management options to reduce methane and nitrous oxide emissions.

The dairy sector and other primary producers have committed to work with the New Zealand government and iwi/Māori to reduce agricultural greenhouse gas emissions at farm level. Read about this and other initiatives in the article The primary sector and climate change.