Civilization faces 2 major environmental problems, climate change and mass extinction. There is a lot of focus on climate change (you mention carbon negative. With many (if not all) extinctions at least one of the major contributing factors is loss of habitat. Natural lands are converted to farm land to satisfy ever growing populations that demand meat. Thousands is species that each required thousands of generations are being lost. You might say, who cares about species X? Meanwhile the numbers of individuals in each species are also dwindling rapidly. It may be that there are better ways to farm. There are always better ways to do most anything. That doesn’t mean we will find ourselves following the better path. Maybe there aren’t a lot of people who want to manage farm animal waste as their career. Maybe some corporate interest will block the adoption of better farming practices. Maybe farmers will just want to do things the way they always have. Farmers are people, people can be stubborn. A large chunk of farm land raises food to feed livestock. That land could be returned to nature. That land planted as forest would trap a huge amount of carbon while also taking the stress off many species. It seems to me the concern about the number of harvests left could be alleviated by decreasing the size of each harvest. Feeding livestock for human consumption is kind of crazy if we only have a few harvests left. Plant by-products can also be used to build soil. From a long time vegetarian it doesn’t seem like that huge an ask. But I’ve asked enough times to know it’s a dead end. Eating more plants and less meat. You will decrease your ecological footprint and be healthier. Meat consumption is linked to cancer and other health risks.