Japanese scientists find 8th-century mystery in tree rings

I noted that Japan had volcanic eruption in 774AD. Would not the debris affect the global atmospheric conditions making it even more difficult to discern what and where the flare came from?

@farmboy ? How are the two related being 200 years apart?

So what, a massive increase in radiation over a thousand years ago gets no comments, while a tiny increase now is the end of the world?