Climate change is real. It’s impact will both be felt by dairymen, and will be influenced by their management practices. That message was heard loud and clear as leading researchers, extension and conservation professionals, professors, energy professionals, engineers and dairy farmers gathered for an intensive two-day conference — with a third day of tours — focused on mitigating the impact of climate change. Held at the Statler Hotel on the Cornell University campus, the conference was co-hosted by Cornell’s PRO-DAIRY program.
While emphasis was given to the fact that animal agriculture in the United States is not the main contributing factor to greenhouse gas (GHG) emissions, experts all agreed that reducing the emissions from dairy farms will be needed as the public becomes more aware and concerned about decreasing the GHG footprint overall. Taking steps now not only will have some positive impact on the environment, it will also position the dairy industry as a leader in sustainability.
“We can go a long way in reducing these emissions by being more efficient in what we do,” Bill Hohenstein, Director, USDA Climate Change Program said. “Worry about farming practices, but also worry about how we are affecting climate.”
Farm practices will have to change as the weather becomes more variable, but changing farm practices can also impact the environment. Weather trends in the Northeast point to increasing severe weather events and extremes, and overall increase in freeze-free season length, higher annual precipitation and warmer temperatures overall. If GHG emissions trends are not changed, these trends will continue to grow unimpeded. Changes in farm practices brought about as a result of these climate modifications will be needed, he said.
Weed, disease and insect pressures are increasing. Heat related animal stress is an increasing concern. The growing season has lengthened in the Northeast. Speakers at the conference emphasized that climate change is going to bring numerous challenges to agricultural, but that the dairy industry will also be presented with opportunities to meet these challenges and remain profitable, while decreasing the GHG emissions from their farm operations.
GHG and dairy productivity
Despite all of the negative press pinpointing animal agriculture as a much larger contributor, GHG emissions from agriculture contribute to approximately nine percent of the overall GHG emission in the United States. Emissions from animal agriculture account for three percent of these, with the rest coming from crop production. Overall, the increase in GHG emissions from agricultural sources has increased about 10 percent since 1990.
The main GHG is carbon dioxide. Methane, nitrous oxide, water vapor and ozone are other naturally occurring GHGs. The impact of each GHG is measured against the impact of carbon dioxide. Methane emissions from agriculture, as well as nitrous oxide emissions, are the two primary concerns.
According to David W. Smith, of Texas A&M AgriLife Extension, animal agriculture accounts for 36 percent of methane emissions in the United States, and 69 percent of nitrous oxide emissions. Of the methane emissions from agriculture, enteric emission accounts for about 70 percent, with manure management responsible for most of the remainder of the agricultural methane emissions.
Nitrous oxide emissions from agriculture are small in comparison to methane emissions, and over 90 percent of these originate from soil management practices. Both synthetic fertilizes and manure applications cause nitrous oxide release after soil application, Smith said.
“All of the manure management techniques have trade-offs,” where GHG emissions are concerned, Smith said.
Increasing milk production, while decreasing energy demands, increases dairy efficiency and is a primary way in which to mitigate GHG concerns on dairy farms, Smith said. Mitigation can increase profitability and productivity.
No matter the statistics, agriculture, along with forestry, do have an important place in GHG emissions reduction.
“The two industries that can reduce their GHG are those that we are dealing with: agriculture and forestry,” Frank Mitloehner, University of California, Davis said.
The dairy industry will need to intensify its efficiency in order to meet the increasing world demand for milk. As cows produce more milk per day, the water, feed and enteric emissions per gallon of milk will decrease if efficiencies are put in place. Increasing the intensity of livestock production can actually decrease the amount of GHG being released, he stated.
“Improving efficiencies across the world is the only way forward,” Mitloehner advocates. “The consumer has no clue about that. They do not make the link between efficiencies” and GHG emission reduction. “We have done a very poor job of explaining how food is provided in this country. That needs to be reversed, fast. If we have problem areas, we need to address them aggressively.”
While the intensification of animal agriculture and dairy in particular may reduce GHG emissions due to increased milk production per animal, there are other considerations. Water and air quality concerns are two important “externalities” which occur with intensification. Food safety, animal welfare, poor resource use, worker health and safety and environmental concerns must all be addressed to sustainably intensify animal agriculture.
“The discussion is much broader than GHG emissions. There are of course externalities,” Mitloehner said. “But by concentrating the animals, you have much more control over the nutrients.”
With methane being 20 times more potent than CO2, controlling methane emissions on the dairy farm is another important GHG mitigation strategy. Separating manure into solid and liquid components, and storing the liquid in covered systems would go a long way to reduce methane emissions, Peter Wright, retired New York State Conservation Engineer for the NRCS, said. Covered manure storage, manure injection, double cropping fields, delivering manure via irrigation pumps and better management of tile drainage systems are other means of mitigating GHG emissions from manure handling.
As climate change becomes an important factor in daily farm operations, dairy farmers will need to modify farm management strategies to address their GHG footprint. Managing the life stages of the dairy cow with herd health and milk production efficiency in mind will play an important role in mitigation. Adapting the farm environment to adjust for increased temperatures, extreme weather events, and their impacts on animal health, safety, cropping systems, and manure management will be required.
“Across the board, you can see farmers changing production practices… reacting to what they see on the ground,” Hohenstein said. “There are a lot of things we can do that make economic sense…practical sense, for farmers.”
Information on the conference speakers, agenda and objectives can be found at: http://prodairy.cals.cornell.edu/conferences/environmental-systems-climate-adaptation