While there might be some short-term positive effects for certain areas of the globe, in the long-term it will be negative for everyone. Having watched two very good interviews with climate scientists recently, both were warning about the collapse of current global systems by mid-century. As things get warmer and climate shifts, many places currently important for producing food will get too hot and too dry for consistent agriculture, and we'll start to see food shortages. Drought and heat will also begin to make some parts of the world unlivable, and people will migrate out of necessity, which given the current political climate, you know how that will go. One of the scientists said that, at current warming trends, the world will reach that level of heat in the 2040s, and we'll start to see the breakdown of current social, political and trade systems. Everyone will be negatively affected at that point.

I'm just a layman on this subject, but it would seem that with how interconnected our world is, it'd be very hard for global warming to be a net positive for most countries. The topic of refugees alone has shown that destabilization in some parts of the world can have reverberations in completely others (e.g. Western Europe).

That said, the very rich who are insulated from practically any externality of climate change, many who are actively building doomsday bunkers, may look very keenly at the opportunities a societal upheaval may bring their way.

I saw a mention that the lack of hurricanes is going to itself be a big problem. Hurricanes are an important way to remove energy from the oceans. Without them, the Atlantic will get significantly warmer, and when storms do form, they are going to be massive beasts.

We are definitely in the "unknown, but it probably won't be good" territory.

People I know who used to be climate change deniers are now saying that even if it's true more CO2 is good for plants so everybody's a winner.

I am pretty sure they will say everything's for the better until it specifically and undeniably affects them negatively.