The trouble with it isn't the basic science. It's the way it's presented, and some of the specific claims it makes.

The simple truth is scary enough without sexing it up, or heading towards a Hollywood disaster movie. Sea levels will rise an amount, an amount of time. We've only got order of magnitude estimates for height and time.

A 50/50 chance of changes in rainfall and temperature greatly reducing our viable crop-lands is far more dangerous than a one in a billion chance of a runaway greenhouse creating another Venus.

But the day responsibly presented science gets the attention of the general public for a long enough for them to learn something, I shall eat this keyboard.