People need something to think about or else life will be dry, whether if it’s necessary or not. That’s why entertainment news and gossips are stimulating.
What was that movie by Al Pachino in which he is a producer and created a virtual superstar? What if Britney Spears does not exist? Who cares? We don’t know her by the person. We know her as who she is on the media.
The same is with Global Warming. Most average people who live in front of the TV or newspaper don’t actually feel it, but the media tells them so. So to them, it exists.
Therefore the same question that you’ve asked can be applied to everything we see on the media. However, when everyone starts to ask the same question, the system collapses… to make room for a new one.