A Cow Walks Onto A Beach
Ruminants, such as cows, sheep, and goats, have a special digestion process that produces large quantities of methane, which has a warming effect 34 times more powerful than carbon dioxide. Ruminant methane accounts for 4 to 5 percent of annual greenhouse gas emissions. Seaweed, which has been used as livestock feed for thousands of years, shows promise for reducing them.
Building on anecdotal evidence from dairy farmers, a team of scientists in North Queensland, Australia, have tested a wide range of seaweeds mixed with feed in artificial cow stomachs. Asparagopsis taxiformis, a species of red algae, reduced methane production by 99 percent—and required a dose of just 2 percent of feed to do so. In live sheep, the same dose led to a 70 to 80 percent drop in methane. Tests have yet to be performed with live cows.
With more than 1.4 billion cows and nearly 1.9 billion sheep and goats inhabiting the planet, scale is a major challenge for this solution. Champions argue it is well worth cracking. If fed to ruminants worldwide, Asparagopsis taxiformis would reduce the amount of soy, corn, and grass required as feed. Most critically, it could dramatically reduce livestock methane emissions.
Technical summaries for each solution will be available May 1, 2017.