I don't think there's a way to really predict such things. The truth of the matter is that 150+ years ago, being aware of things that were happening in other countries wasn't as easy to do. Modern technology makes us all too aware of the rest of the world. If Haiti or Japan had a massive earthquake 200 years ago, would we have necessarily known about it? Unlikely. There has been unrest in the middle east since the dawn of civilization. Dating back into recorded history as far back as during the times of the Pharaohs.
People thought the apocalypse was near during the two World Wars, because so. much. of the world was at war. I think the feelings that we have now about how bad the world has gotten is not unlike how people thought 60-70 years ago when the first World War was going. And that was WITHOUT CNN and MSNBC and FoxNews and the internet and YouTube showing footage from every which place and angle. Could you imagine what the panic would have been like during WWII with HD cameras capturing the footage as American troops invaded the concentration camps?
I feel the same way about "global warming." We never had the kind of technology that helped us determine what the "core" temperatures were and if they were up or down by a fraction of a degree, so how do we know that the trends that we're seeing in the weather are not a natural pattern that occurs every 100-200 years? We went from dinosaurs to an ice age to the "thawing" of the ice age... how do we know that these things don't just happen naturally? Personally, I think Al Gore needs to focus more on manbearpig and leave the environment alone. That said, I don't think that we should be irresponsible with the earth. We should do what we can to reduce our emissions, we should recycle what we can, and not destroy what natural resources we have left. But I think that's just good stewardship of the place we call home.