You will find reports of cases relating to environmental law in series with general coverage (national, foreign or international scope). There are also a small number of specialised reporters.
European Court of Human Rights
The HUDOC database [open access available to all with access to the internet] provides access to the case-law of the Court (Grand Chamber, Chamber and Committee judgments and decisions*, communicated cases, advisory opinions and legal summaries from the Case-Law Information Note), the European Commission of Human Rights (decisions and reports) and the Committee of Ministers (resolutions).
*Committee decisions appeared on HUDOC only as of April 2010. Decisions concerning single judge cases are not published. Commission decisions prior to 1960 exist in hard copy only in the Court Archives.