I don't know what "slaughter your cattle to reduce greenhouse gases" refers to specifically, but Greenhouse gases are bad and reducing them is good. As I see it the only way to meaningfully take action on it is by government control. I don't actually like this but it's just the reality of the matter: companies will keep doing what nets them a profit, and millions of consumers can't really do an in-depth study on everything they buy, and the only party that can take meaningful action is government. I think climate change denial has always been primarily about opposition to government action, and not so much about the science of it.

"You shall not leave your residence", presumably, refers to COVID lockdowns? Most of the world had these kind of restrictions, including the US, and some locations much more severe than Europe. Many people thought they were a good thing and followed them because of that, and didn't blindly follow government for the sake of obeying the government.

And in both cases there was/is plenty of opposition too (presumably anyway, because I don't exactly know what you're referring to).

People can protest. People can vote different. They can go on the internet and TV and say politicians are a bunch of wankers. Comparisons with "totalitarian states" is just silly.