Climate protection: Seaweed for cows

Photos courtesy U.S. Department of Agriculture

Friends have been telling me these great ideas for how to stop global overheating pollution.  One idea is to feed seaweed to cows.  It sounds weird, but, as my friend said, “hear me out.”

Globally, 79% of greenhouse gases are carbon dioxide and methane from people burning fossil fuels – gasoline, natural gas and coal.  In terms of how much they heat up the global climate, 21% of human-created greenhouse gases are methane. Methane is the main element of natural gas. Methane escapes into the air through leaks during processing, shipping and pipelines that bring natural gas into your home.  Methane also gets released during coal mining, and during oil pumping and refining. When we stop burning natural gas, gasoline and coal, we will stop 37% of the human-caused methane releases.

The rest of the methane releases come from rotting sewage, landfills and agriculture. Rotting sewage and landfills produce 20%.  Agriculture emits 42% of the human-released methane. Because human-released methane is 21% of the greenhouse gases, agricultural methane is 9% of global human greenhouse gas emissions.

That is just greenhouse gas emissions. Globally, agriculture also contributes to global overheating by cutting down trees. An acre of mature Western Washington forest eats up about 2 to 5 metric tons of carbon dioxide each year. (Five tons is how much is released by a gasoline car that gets 25 MPG driving 15,000 miles.)  When a forest is cut down to make way for farming, it no longer eats as much carbon dioxide.

To see the cow-seaweed opportunity, set aside cutting down trees and focus on agricultural methane releases. Of the 9% of greenhouse gases that are agricultural methane, 32% are cattle gas.

You may have heard about cow farts. Some of the methane does come from farting. Most of it comes from burps. Polite scientists like to blame “enteric fermentation.” That is a confusing euphemism. Enteric fermentation is how cattle digest grass. It is not the same as cattle gas. We can stop cattle gas without stopping enteric fermentation. (That’s where seaweed comes in). Cattle gas and grass digestion are two different things. Altogether, cattle gas produces 6.4% of the greenhouse gas heating of human activities.

It turns out that supplementing cattle feed with particular seaweeds can almost completely eliminate cattle gas. When we get every rancher to feed their cattle seaweed supplements, we will cut global greenhouse gas emissions by about 6%.

You might think that going after 79% of the greenhouse gas emissions is a better idea than going after 6%. I did at first. But consider how many people you have to convince for the 79% benefit of stopping burning fossil fuels. There are about 1.5 billion cars and trucks in the world. How many people do you have to inspire to buy an EV to get them all replaced? Probably something like 1.5 billion car shoppers.

There are probably somewhere between 100 thousand and 2 million people worldwide who decide whether to feed seaweed to cattle.   Compare that to the 1.5 billion car shoppers. That is 1 cattle boss for every 750 to 15,000 car shoppers.  Each rancher who chooses seaweed will have over 50 times the impact on greenhouse gas emissions as a car buyer who chooses electric. Maybe over 1,000 times the impact.

Both groups have to be inspired. We need to convince the ranchers and we need to convince the car buyers. When the last cow stops burping, we will have to stop whatever fossil fuel burning remains. Otherwise, the world would continue heating and the crazy changes in climate would get worse and worse. And vice versa: When the last gasoline car is junked, we will still have to stop the remaining cattle gas.  If all we did was stop burning fossil fuels, cattle gas would go from 6.4% of human greenhouse gas emissions up to 30%.

If you would like to work on improving the comfort and lives of cattle, don’t hold back. A leading supplier of cattle feed seaweed is Blue Ocean Barns in Kailua-Kona, Hawaii. They are currently seeking to hire a full-time algae technician. The responsibilities look like a blast if you’re a gardener/aquarium person who enjoyed science labs in school. You would have to move to Kailua-Kona. (The words “tropical paradise” come to mind.)

For me, I am focused on stopping gasoline burning and stopping natural gas burning. Along with coal burning, those are the sources of 79% of global overheating pollution. If you want to get seaweed into cattle, go for it. It’s an important part of stopping climate change.

— By Nick Maxwell

Nick Maxwell is a certified climate action planner at Climate Protection NW, teaches about climate protection at the Creative Retirement Institute and serves on the Edmonds Planning Board.


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