On the whole, the US dairy industry has become more efficient and sustainably focused over time. As the overall number of farms has dropped dramatically, the average size of a dairy farm has grown. From 2007 to 2017, a gallon of milk required 30% less water, 21% less land and made a 19% smaller carbon footprint. U.S. dairy, per gallon, has the lowest carbon footprint of any country in the world. The number of U.S. dairy farms has fallen by half since 2006. Over that period, milk production has increased 24%, and milk per cow has grown 20%.
Even with this success, agriculture is a major contributor to greenhouse gas emissions. Greenhouse gases have been shown to increase the effects of climate change. All sectors need to adapt their practices to a more sustainable model in order to mitigate the effects of climate change. To this end, U.S. Dairy has set a goal of being net carbon zero by 2050.
Biogas systems (anerobic digesters) are one area that dairies can explore to reduce emissions. Dairies have a particular problem with manure, as milking cows produce more manure than beef cattle. Biodigesters convert manure into power, and farms can sell that power to the grid. Biodigesters help to reduce manure runoff into lakes and streams, reducing water pollution and algal blooms. They also help trap methane, thereby reducing the emission of greenhouse gases into the atmosphere. Farmers can also use the by-products of fermentation as fertilizer for their fields. The fertilizer doesn’t smell as much as fresh manure, and can save a lot of money for the farm. A farm with about 3,000-5,000 cows will produce enough energy through a biodigester to profit fairly quickly. For smaller farms, experts recommend adding food waste to the biodigester, keeping food out of landfills and adding to the efficiency of power production. Alternatively, some small dairies are working together to run one biogas system for the group.
Biodigesters can be expensive to build and maintain, so the most successful states have seen legislation supporting the practice with funding as well as other incentives. Vermont’s program, Cow Power, has been active for over a decade and has put Vermont ahead of 30 other states in terms of number of biodigesters. California’s state government has underwritten over 50 biodigesters in just a few years, and California even buys dairy biodigester power from other states to achieve its goals for renewable energy sources.
While some find U.S. Dairy’s goals to be lofty, others think they could do better. The World Wildlife Fund (WWF) completed a study that suggests dairies could reach net zero carbon emissions within five years, rather than 20+. This is much more in line with what climate scientists are calling for- the need for action is urgent.
Feed production and efficiency is one of the four areas in which the study focused (the four areas are also cited by U.S. Dairy and others as the best ways to reduce GHG emissions.) The other three areas are reducing enteric methane emissions, improving manure management and nutrient recovery, and the generation and sale of renewable energy and byproducts.
We discussed enteric methane emission reduction in a previous article; seaweed has been found to greatly reduce methane production when fed in small amounts. Improving manure management and nutrient recovery and the generation and sale of renewable energy and byproducts are both accomplished with anerobic digesters producing biogas. However, the study acknowledges that for such a fast turnaround, the goal must be supported by government policies, subsidies, and support. Without incentives, the goal may not be met for decades.
Incentives have historically been hard to find and inadequately funded. Farmers operate on a fine line between financial success and business failure. They must have support from the government in order to run their farms in a more climate-friendly manner.
The roughly $370 billion climate and energy spending deal recently passed as the Inflation Reduction Act will bring the country closer to cutting greenhouse gas emissions in half by 2030, according to new analyses. While financial support for biodigesters was cut from earlier drafts of the bill, there are still policies and supplements that will help dairy farmers cut emissions. Approximately $20 billion has been earmarked for agricultural practices, including incentives to help farmers create habitat for pollinators like bees and butterflies, store more carbon in the soil, and make farms more resilient in the face of extreme weather.
Roughly $8.5 billion from the bill goes to the USDA-run Environmental Quality Incentives Program, which pays for farmers to plant cover crops. These crops, such as clover or rye, are planted to prevent soil erosion and to help keep carbon in the earth rather than releasing it into the air. Cover crops also promote biodiversity among pollinators, giving bees and bugs a home to hide away in. Currently only about 5% of farms in the US plant cover crops, but increasing that number will improve soil conditions, increase wildlife diversity, reduce the amount of fertilizer needed, and slash greenhouse gas emissions.
The scientific community has come to a consensus: all commercial sectors must work together to limit the damage done by climate change. The dairy industry has made great strides, but progress must continue. By considering the health of our soil, the biodiversity of our land, and the many uses for methane and manure, dairies can diversify their income and produce more milk. The government must continue incentives to support these efforts and to encourage dairy farmers to take a leap of faith.