Climate Change is scary, I remember when I was 12 and saw An Inconvenient Truth for the first time, and that was far more frightening than many of the other things that kept me up at night such as terrorists and my inexplicable fear of hairdressers. But, it's not all doom and gloom, there are positive aspects that can derive from being scared, and one of those is taking action to change the path we are currently on.
This clip by SciShow both dramatically and articulately describes the worst possible scenarios that come out of climate change, that could occur in the next century or more. He breaks it down to the 5 worst outcomes, most of them already known but are explained easily. He talks about effects such as melting ice caps, sea-levels rising, acidification of ocean waters and damage to the Thermohaline Circulation (which is the scariest).
But don't let it get you down, fear of the worst should motivate everyone to fix it, because climate change is anthropogenic, which then in turn means we have the power to reverse it, to change it and create a better world.
Here's the clip: