For most countries around the world, sourcing energy entirely from wind, solar, geothermal, and hydropower by 2050 would reduce their energy needs and costs, improve air quality, and help slow climate change, according to a study in Environmental Science & Technology.
those are all problems of production. production doesn’t decrease because anybody goes vegan. veganism has been around since the '40s, meat production has only increased since then with a few exceptions that have nothing to do with people being vegan.
Almost nobody has gone vegan during a time period where the population affluent enough to afford regular meat on a regular basis has increased many times over.
If a meaningful chunk of the affluent population went vegan, we’d absolutely see a lot less meat produced. At the individual level, it’s going to make a very modest difference, but that’s how mass changes start.
there’s no reason to believe it makes any difference at all.