Karl Czymmek
PRO-Dairy, Dairy Climate Leadership Specialist
The Northeast dairy industry has made significant progress in a range of sustainability measures between 1971 and 2024, especially greenhouse gas (GHG) emissions, according to “Fifty years of environmental progress by U.S. dairy” published June 2024 in the Journal of Dairy Science by Dr. Alan Rotz, U.S. Department of Agriculture Agricultural Research Service (USDA-ARS), and colleagues. The research team evaluated six dairy regions across the U.S., comparing typical practices on dairy farms in 1971 and 2020 for emissions of the greenhouse gases carbon dioxide, methane and nitrous oxide, using a well-documented and widely published life cycle assessment model developed by Dr. Rotz during his career at ARS.
Dairy farming in the Northeast U.S. covering 10 states from Maryland to Maine, including NYS, shows excellent sustainability progress based on this study. During the 50-year period the Northeast dairy industry has:
Increased annual milk production per cow by 150 percent from 9,250 pounds (fat and protein corrected milk, FPCM) to 23,144 pounds FPCM.
Increased total yearly milk production by 27 percent from 24.4 billion pounds to 29.4 billion pounds.
Reduced number of cows by 49 percent.
Decreased carbon intensity of milk by 42 percent from 1.69 pounds of carbon dioxide equivalents/pound of milk to 0.97. Each greenhouse gas has a different heat trapping potential and carbon dioxide equivalent is a way to weight the global warming potential of a greenhouse gas over a period of time, typically 100 years. The Rotz study used the 100-year timeframe.
Reduced absolute dairy GHG emissions by 24 percent.
Decreased absolute methane emissions by 13 percent and nitrous oxide by 42 percent.
Progress by dairy farmers in this region results from implementing advances in animal care, nutrition, genetics, forage management, agronomy, and energy efficiency and dairy farmers have made further progress since 2020, including continued increases in milk production per cow. The study also found that the type of dairy management system did not predict a high or low carbon intensity value. This suggests that well managed dairies of any type or size can meet environmental sustainability goals.
Farmers are always looking for ways to do more with less. This study demonstrates that for Northeast dairies, farm economics and the environment have benefited simultaneously.
PRO-DAIRY is a nationally recognized extension and applied research leader serving dairy farms for more than 35 years.