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 Aotearoa New Zealand’s greenhouse gas emissions, and they are working on ways to reduce them.
Dairy farm research and climate change
DairyNZ is conducting considerable research into how dairying impacts climate change as well as the impacts climate change is having on the dairy industry.
Statements to create discussion:
Elena says that the impacts of dairying and agriculture on climate change are similar to any other industry or big human activity done at scale.
Ben talks about the moral obligation he bears as a farmer to do something about climate change.
Ben also mentions the effects extreme weather events are having on farming.
Holly says that milk production levels need to continue to feed the world but with an emphasis on reducing emissions.
Consider what other information you may need in order to critique these statements or to justify your own statements.
Dairy – a significant part of Aotearoa New Zealand’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.
Effects of drought
Reduced amounts of rainfall can cause drought conditions. This impacts pasture forage. Pictured is Scott Farm during an extreme dry event in 2013.
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.
How is the climate changing?
Climate change expert Professor James Renwick points out some of the changes we are starting to see regarding weather events.
Questions for discussion:
What is the relationship between warmth and moisture?
How does this relationship affect weather and climate?
James says that we are not seeing more storms. Why might people think more storms are happening?
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.
Nature of science
Scientific developments are influenced by societal needs. Agricultural sectors are contributing to research on greenhouse gas reductions through improved plant and animal breeding and via changes to farm management practices.
Activity ideas
Investigate long-term average annual temperature and annual precipitation data for 30 sites from Kerikeri to Invercargill to view variations over time with the activity Using weather data.
Using infographics challenges students to delve into infographics and how they present science information related to climate change.
Useful links
Find out about agricultural greenhouse gases on the DairyNZ website.
Read about climate change and agriculture On NIWA's website in the Science topics for students section.
Low-emission feeds have the potential to reduce methane and nitrous oxide emissions.
Acknowledgement
This resource has been produced with the support of DairyNZ.
DairyNZ
DairyNZ is the industry organisation that represents all New Zealand dairy farmers. DairyNZ supports farmers through investing in research, resource development, extension and advocacy to ensure sustainable dairy farming and food production.
