Ken Nordlund: Cars are more the culprit of global warming than cows

February 24, 2019
Ken Nordlund

Michael Graham’s column, “ The war on cows,” in last Sunday’s State Journal was seriously flawed in its take on the Green New Deal.

It incorrectly claimed livestock contribute more greenhouse gases to global warming than the entire transportation sector, and it disparaged the intensive farming operations that dominate Wisconsin’s dairy industry.

Dairy farming is a demanding occupation for thousands of Wisconsin families. These people care for the cows that produce our milk, cheese, ice cream, yogurt and the butter that makes everything better.

I fully accept the scientific consensus that climate change is real, that human activities are the major contributor to the change, and that we all need to do our part to achieve a solution. I also accept that livestock are significant contributors of greenhouse gases to the global warming problem.

But livestock do not emit more greenhouse gas than the transportation sector worldwide. As measured by “direct” emissions, livestock produce about 5 percent, and the transportation sector about 14 percent. When “indirect” emissions are included — such as exhaust from tractors, electrical generation on farms and trucks hauling milk to processors — the total emissions from livestock contribute about 15 percent of the total.

The indirect emissions from the transportation sector are extremely difficult to estimate, but would include oil drilling, fracking, refining, car and airplane manufacturing, and on and on. Experts are reluctant to estimate the combined direct and indirect emissions from the transportation sector, but they are certainly much larger than the direct emissions alone.

The myth that livestock release more greenhouse gas than the transportation sector started in a 2006 Food and Agriculture Organization publication called the “Livestock’s Long Shadow.” But that report has been subsequently discredited. The primary author of the flawed FAO document, Henning Steinfeld, recently explained the error. The publication compared the combined direct and indirect emissions from livestock to the direct emissions only from transportation, while omitting indirect emissions.

Livestock are not greater emitters than our cars, trucks and airplanes. That said, livestock remain as significant contributors to the greenhouse gas problem.

The second major misconception in the column was its implication that intensive livestock production is worse than more pastoral dairy industries.

Early this year, the Food and Agriculture Organization of the United Nations produced a report called “Climate Change and the Global Dairy Sector.” It reported a worldwide dairy average of 2.5 pounds of carbon-dioxide produced per pound of milk, with a high of 6.7 pounds in sub-Saharan Africa, and a low of 1.3 pounds in North America.

In dairy cattle, greenhouse gas emissions are affected by the quantity of feed the cows consume. If we evaluate two cows, one producing 4 gallons of milk per day and the other 12 gallons, the lower producer may eat 36 pounds of feed per day, and the higher producer may eat 55 pounds. The higher producing cow eats 50 percent more feed but produces 300 percent more milk.

So higher yielding cows produce less greenhouse gas per gallon of milk. If the world’s supply of milk is produced by fewer but higher yielding cows, greenhouse gas goes down.

Since 1950, a substantial increase in greenhouse gas has occurred in the atmosphere. Yet the U.S. dairy industry has reduced its production of greenhouse gas by about 40 percent. It has achieved this by reducing the national cow herd from 25 million cows down to 9.5 million while increasing average milk yield per cow more than five-fold from about 4,000 pounds per year to some over 22,000 pounds today. And the most intensive dairy farms in this state average more than 30,000 pounds per cow, per year.

We all need to do our part to solve the climate change problem. Dairy farmers should continue to increase productivity per cow. Dairy nutritionists can include feed additives such as ionophores to reduce methane production and increase efficiency. Larger dairies can capture methane from stored manure and burn it to generate electricity. Meanwhile, we consumers who drive past modern confinement dairy farms should at least give a respectful nod to the most environmentally friendly producers of dairy foods on the planet today.