While there's no shortage of things to worry about, a new survey from Pew Research has actually quantified what it is we fear. They've found (not suprisingly) that our fears depend very much on where we live.
If you live in the Middle East, religious and ethnic hatred tops your list. If you live in the United States and Europe, inequality keeps you up at night. In most of Asia, pollution looms large - though South Korea follows the United States and Europe in singling out inequality as a leading threat. Japan also breaks with the regional trend by worrying most about the spread of nuclear weapons.
In Africa, the spread of infectious diseases, especially HIV/AIDS, is public enemy number one - and this survey was taken before the Ebola outbreak became a global story, so we can only assume this fear has been compounded by recent events.
While the United States collectively sees inequality as the largest threat, there's a clear ideological breakdown to those results. Republicans were more likely to identify religious and ethnic hatreds as the top threat, while Democrats singled out inequality. Independents were slightly more likely to finger inequality as the top threat as well.
Pew found a similar dynamic at work in the United Kingdom, with conservatives more concerned about religious tensions than inequality.