More looking at treaty signing data

I tried filtering out the treaties that the ENTRI database considered environmental but I don't - either because they don't meet my definition of environmental or because they have subsets that do meet my definition but aren't the primary point of the treaty. That basically took me from this:

to this:

Obviously, there are fewer treaties. Germany (representing Europe) is still ahead of the US, even going back historically (although the gap is narrower in the 60s and 80s). Now that I've actually looked at all the treaties one by one, I have some thoughts on this - I think it IS at least partly because European countries had reason to sign a number of local environmental agreements that weren't open to others, particularly in earlier decades. By the 1990s, however, Europe is just flat-out signing more, as far as I can tell.

The other thing I notice is that, filtering out the treaties that don't look to me like "true" environmental treaties, there's no longer a clear peak in the 1970s, except in China. Both the US and Germany sign more environmental treaties in the 1990s.