I find this hard to believe. Here is my epistemic estimation: if this were legitimate, it would be huge news. I've been hearing about this for several years now but somehow it never amounts to anything. I would have expected large scale cattle studies by now but I have not seen any of those.
1) It IS huge news. It's been reported pretty heavily. (Or at least, I've stumbled across this news many times from many different and mainstream sources. I suppose it's possible that my filter bubble is making it seem like a bigger deal.)
2) What's the incentive for the farmer? The benefits are entirely externalized. Less methane is good for the planet, but paying to add seaweed to the feed is nothing more than an added case for the farmer.
So if we wanted to roll this out, we'd have to provide publicly-funded incentives for farmers to do so.
There may be no incentive for the farmer but plenty of incentive for the scientist, the government and the philanthropist.
My conclusions is that GHG from cattle is simply not as big of a deal as the environmentalists would make it seem. Another comment mentions that decaying grass also releases methane so I'm not even sure if there are any accurate numbers on the true effect of livestock on emissions.
re: decaying grass, it's a question of speed and cycles.
All plants eventually decompose, but it happens at a much slower cycle than if we actively harvest it, feed it as grain, grow more where the original harvest was, etc. By speeding up the cycle, we end up with much more of it. Or at least that's my non-scientist take.
We gotta remember that "greenhouse gases" aren't a bad thing. They're fundamental to making Earth hospitable for life. But there's a balance. When we speed up the "carbon cycle", we end up with too much of the stuff, which throws the whole system out of balance. But we could just as easily end up with too little some day in the future, which would cause us all sorts of other problems.
As for whether we have truly accurate numbers for any of this, I too am skeptical. But it's early days for research in this area. One or two studies doesn't cut it, but that doesn't mean they're not onto something huge.
You find it hard to believe that a $66 billion beef industry doesn't want to completely overhaul its logistics and incur massive switching costs and larger overhead?
The first problem is that cattle account for about ~5% of the emissions from industrialized countries. So it's not actually that high of a priority from a climate standpoint. It's also not the first time that microbial fermentation has been successfully diverted away from methanogenesis; look up "biohydrogen" to find other examples where H2 is the terminal electron carrier instead of CH4 (I assume that happens here; fermentation needs an electron sink). Furthermore, a high proportion of the emissions related to agriculture comprise fertilizer-derived nitrous oxide, which has a longer half-life than methane and is thus more damaging. Further-furthermore, you still have open questions on how this affects long-term health and the rumen microbiome, which simply won't be answered quickly.
The smart money IMHO is on lab-grown meat. I expect seaweed may feature into a future market for ethically sourced fancy cheeses, but is unlikely to affect the market for staple foods.
