It's probably wrong to call climate scientists "scientists", just like it's wrong to call rocket scientists "scientists". They are probably more like engineers,

It's probably wrong to call climate scientists "scientists", just like it's wrong to call rocket scientists "scientists". They are probably more like engineers, but "engineer" is almost a protected title (except in software). No, they don't have a crystal ball. But just as nuclear weapons required a little forethought and co-ordination between nations, so does the ability to inflict colateral damage on the biosphere in a way that has never been done before. Unlike the last 5000 or so years of human history, we are making new and significant discoveries every year, and are able to roll them out across the whole world. The cost is we need to be a little cautious about them. Civilizations have collapsed before. New technology might be a factor - the ability to suddenly exploit a new resource can cause that a massive expansion, then a crash as the new resource becomes depleted. And more complex civilizations can be less able to survive a crash, as specialists are forced to become generalists in order to survive - doctors driving taxis or trapping gophers are much less productive. Sometimes scientists get worried for no good reason (Y2K?), and sometimes they have a good cause (radium), but there's no way to be sure. Not everyone should listen to all the doom and gloom (from reputable sources), but world leaders certainly should. And sadly, they only seem to listen when wide-eyed protestors shout slogans outside their offices. It's kind of depressing.