What are some reasons European countries might not want to part of the European Union?

They don't want to lose their economical independence and that it will ruin them financially.

Explanation:

We can take the example of Norway. This Scandinavian country is not a part of EU because they have developed industry, including oil fields, fishing, agriculture. They believed that entering EU they will lose their monopole and stability in this areas.

answeramicable; (friendly);

it is very hard for the climatologists to precisely predict how will the global temperatures be changing so there's lots of models, some of which differ significantly, this is due to multiple factors, and probably the most important is the human activity.

humans have been a key factor in climate change around the globe since the start of the industrial revolution, and in the past few decades the consequences are becoming more obvious. there's lots of emission of pollutants in the atmosphere as well as changing the environment on the surface itself, so it's really hard to predict how will that go in the future because there's some countries that are reducing the damage and are going towards green energy, while others are stubbornly continuing with pollution and damages to the environment.