There's a point where the evidence is so strong and from such geographically distinct and separated places that it's best to assume it's a global problem. Waiting any longer would be too long and reminds me of this comic: http://farm5.static.flickr.com/4036/4254681996_27b1ed7ff0.jp...

We know there's a crisis with plastic in our water and entering our food supplies, even killing our fish and birds. We know CO2 levels are rising. But there's one place where we don't have any data about these two problems: North Korea. Saying we should wait until we get data from North Korea to judge whether or not it's a global problem isn't restraint. It's being intentionally obtuse.