"I think if every single person on Earth went vegan it would have a significant impact."

It will never happen.

We need more practical solutions.

Only 10% of people in developed countries would even think of making major changes to their lifestyle for such reasons ...

And there are 5 billion people in poor countries who are rapidly becoming 'consumers' and they don't care, at all. They want cars, appliances and 'stuff' now.

There's hope but I think it'll have to be really quite pragmatic, and more focused on supply and less on demand, i.e, solar, wind, a lot more nuclear and I wish we'd invest more in Fusion research.

Going vegan is essentially "Stop buying stuff" where "stuff" is meat. You should stop buying anything that pollutes a lot and/or has low value compared to alternatives: diesel cars, disposable plastic items, useless gadgets, etc.

If you still want meat in your diet, start buying less beef and more eggs or chicken. That'll be a good start. https://timeforchange.org/eat-less-meat-co2-emission-of-food