Seaweed the hero?

Researchers from the University of California, Davis, tested a seaweed-based supplement for grazing beef cows on a ranch in Montana. They gave 12 cows the supplement but left another 12 without it; the cows wandered around for 10 weeks, burping as usual, but the ones that ate the supplement produced 37.7% less methane than their buddies — and showed no differences afterward in terms of health or weight.

That’s an enormous improvement, especially of a greenhouse gas that is substantially more powerful a warming agent than carbon dioxide, though on a shorter time scale.