I watched this one a couple of weeks ago and enjoyed it a lot, though I chose not to mention it in these parts as it's a difficult one to discuss without veering towards the political. Like most sci-fi - which it is after a fashion, I suppose - it is inevitably a social comment on our world as it is. I took it as being an allegory for climate change and the various stripes of reaction to that. Without getting into the politics of what is right and wrong therein, I thought it pretty well skewed all sides, in particular the difficult balance of what is scientifically necessary versus what is politically palatable within a popular narrative, the reaction to 'expertise' in the present era, and how people in general can readily reject or ignore a reality which they do not want to confront. Is it necessary? Well, that probably depends on individual reaction. I suspect it will mostly be hailed by those who agree with its message, and dismissed by those who do not, as was ever the case. IMO, it's biggest problem with reaction has been among critics who have slated it for not being a comedy while seemingly not quite understanding it's a satire.