Ok, so, not “cows;” bison. A study in Romania found that European Bison are helping sequester carbon (though it isn’t peer-reviewed yet as far as I can find) and another study (that is peer-reviewed) suggested that American Bison and other animals can too. The first study allegedly (it’s not published, so I don’t know for sure) claims that bison can improve a grassland’s carbon sequestration by up to 9.2x, but most people seem to think it averages around 2x.
Obviously, rewilding was probably already a goal of everyone here, but I think it’s an interesting concept that animals can actually make carbon sequestering more effective since we’re all taught that animals emit CO2 and plants absorb it. I really haven’t heard anything about this until I got Wren’s “good climate news” email today, even though the second study I linked was published in early 2023, and I wanted to share. I also want to know what everyone’s thoughts on bison meat in this regard. Is heavy bison farming prone to the same environmental pitfalls as cow farming, or is their historically huge population (at least for American Bison) a sign that they can’t really get that bad?
Meat production, especially beef, tends to get a bad rap from the environmental movement in general. Arguments are put forward pointing out that the amount of water consumed, the land required and the carbon emissions generated to produce a kilogram of beef are much greater than for a kilogram of soybeans which has a similar nutritional value.
If we look closely however, we see that these figures are for cattle that have been lot fed. That is that they are fed on grain, soybeans and other farmed fodder from the time they are weaned. Lot feed is wasteful for those criteria as well as raising animal welfare issues.
Rangeland grazing, where animals feed on native pasture is quite a different story, even where an animal might undergo a period of lot feeding to fatten them up for slaughter in the last few months of their life.
The truth is that large parts of the Earth’s surface are unsuitable for cropping because they are too arid, infertile or have unsuitable topography. If it were not for grazing these areas would not produce any food.
It is true that grazing does impact on the ecology of ecosystems, especially in a country like Australia which has not had grazing megafauna for 10,000 years or so. It is still unlikely though, that grazing would have a bigger impact than clearing these areas and cultivating them for crops.
Grazing grasslands over time tends to favour woody vegetation over grass and herbs. This is bad news for a number of reasons as outlined in the article linked below. https://www.nature.com/articles/s41598-020-65094-x
On the plus side though, the increase in woody vegetation on rangelands also provides a massive CO2 sink that offsets the methane emissions of cattle several times over.
There are ways to manage rangeland grazing to reduce it’s impacts. These include fencing off sensitive area and water bodies and using rotational grazing.
Recent research suggests that introducing bacteria found in the stomach of kangaroos to cattle might have the potential to reduce methane emissions. https://www.opb.org/article/2023/03/06/how-kangaroo-gut-bacteria-could-help-cut-a-potent-source-of-greenhouse-gas-emissions/
Another option may be to harvest the extra woody vegetation from grasslands and use it as biofuel.
Yes I remember learning that you can’t have a net carbon zero agricultural system without animals (at least not a self-sustaining one), and there is a lot of good regenerative agricultural work being done with cattle.
I think I was also told that there were more bison in North America 500 years ago than there are cattle today.
Depends on who you ask. The current population of cattle is ~950 million (~90 million in the usa). Most people don’t think bison populations were ever that high, but some people do and just because they’re the minority doesn’t mean they’re wrong
It might not be too surprising that there more bison in North America than there are cattle today. Prior to European settlement bison roamed over vast areas, including a very large north, south seasonal migration. A large percentage of land in that continent is now devoted to cropping, especially cereal crops. Cropping land is mostly on the more fertile soils in areas of higher rainfall. These would have been prime grazing lands for bison and may have sustained a higher population than modern day cattle herds.
The basic idea is that manure makes plants grow faster. It can be grass or trees. However, too much fertilizers can kill trees. The manure will be broken down by earthworms and other decomposers. so the soil stays fertile.
I guess chickens and goats can perform the same function. However, if over grazed, the land looks like a dust bowl in dry weather.
It depends on the natural vegetation. Our fynbos prefers sand. Manure and fertiliser promotes invasive alien weeds - or ‘horticultural horrors’ if that is your preference ;~)
My twin, a botanist, described how shocking it was to go to Ecuador and Bolivia and see how much of the forest has been chopped down and/or burned to make way for cattle farms. Mile after mile after mile of the landscape has been razed to make way for cows. It’s encouraging to see bison returning to North American and Europe, but what’s happening in South America is a catastrophe.
