I do agree that it's hard for nations to all agree on a collective set of rules for anything (Bitcoin, climate change, etc.). That being said, I think that if governments around the world really wanted to regulate Bitcoin, they could. If theoretically they made it illegal to mine Bitcoin/cryptocurrencies, illegal to own a copy of the blockchain for whatever reason, people would have to comply with the law or face repercussions. Something like this is obviously very unlikely in Western countries that are more liberal about Bitcoin, but still a possibility in many other places around the world.

We already see some regulation in Western countries, with the US for example treating Bitcoin and other cryptos as a security, making it harder for Americans to participate in ICOs, and causing tax implications that would not otherwise happen had they regulated Bitcoin as a currency.

Ultimately I think Bitcoin regulation will be as effective as the government enforcing it. Climate agreements are not too effective since nations are not going to go into a war for not meeting certain CO2 emissions goals. Nations can't really force other nations into meeting any deadlines/deals either. However, governments have full enforcement of the laws in their own countries. If they want to enforce certain Bitcoin regulations, or outright make things illegal, they can absolutely prosecute anyone that attempts to skirt these regulations.

There is a huge difference between bitcoin and the world's temperature.  Bitcoin is a cryptocurrency and we deal here with digits and value while temperature and global warming are referring to the weather conditions.

Bitcoin regulations is not harmful to bitcoin. The said regulations being placed by the countries to bitcoin are just protocol being made to any financial activities. The same regulation being placed upon the banks and the securities. There is nothing wrong with complying with KYC and AML regulations.