Scholarship trends in international environmental law

Over at Legal Planet Dan Farber asks, "What do the numbers show about the trajectory of scholarship in international environmental law?":

It can be difficult to identify patterns  in legal scholarship.  One way of doing that is to check on the frequency of key words, using Westlaw or Lexis-Nexis to track the numbers.  There are some interesting patterns in scholarship on international environmental law:

1. The field came into its own in the decade from 1987 and 1997.  Indeed, the phrase “international environmental law” was barely used at the beginning of that decade but commonplace by the end.
2. Key ideas from international environmental law such as sustainable development and the precautionary principle have found footholds in U.S. scholarship.  Attention to these concepts grew continuously from 1987 to 2007 but may have stabilized since then.
3. There has been steadily growing attention over the past 15 years to international agreements dealing with climate change and oceans.

His blog has the numbers.