Despite everything you read in the newspapers about shooting sprees, and terrorist attacks, and civil wars, as a proportion of the world's population more and more of us are living free of violence and dying of natural causes. You can see this in data on rates of death in tribal warfare, which are far higher than those of modern societies, even in the midst of wars. You see this in calculations of rates of homicide over history. A contemporary European has about 1/50th the chance of being murdered as his Medieval ancestor. You see this in the abolition of barbaric practices that were ubiquitous through human history and then were abolished: human sacrifice, throwing virgins into volcanoes to placate an angry god, burning heretics at the stake, breaking people at the wheel, executing people for shoplifting or counterfeiting, legalized slavery.
Less obviously, you see it in rates of death in warfare. War has not been abolished but it is far less destructive than it used to be. The rate of death in warfare now is probably a hundredth of what it was 50 or 60 years ago. The reason that we have the impression that the world is a violent place is that that's what news is about.
News is about stuff that happens, not about stuff that doesn't happen, and all the parts of the world that are free of war, that are free of terrorist attacks just don't get reported to us and so we forget about them.
We're getting better and better at reporting the violent events that do occur. Something blows up, you can be sure you'll hear about it, but we don't appreciate how much of the world at any given time is at peace.
Pinker, S. (2011). The better angels of our nature: Why violence has declined. New York: Viking. (library)
Steven Pinker charts the decline of violence from Biblical times to the present, and argues that, though it may seem illogical and even obscene, given Iraq and Darfur, we are living in the most peaceful time in our species' existence.