The history of international environmental law as an academic topic is generally associated with the emergence of treaties and case law on specific sectors such as shared watercourses, the oceans, or – from 1900 onwards – selected wildlife species. Doctrinal attempts at identifying common (trans-sectoral) elements, and a coherent discipline of international regulation and governance in this field, did not make their appearance until well into the second half of the 20th century, with a prevailing and near-exclusive focus on public international law.
One notable exception was the pioneering work of Karl Alexander Neumeyer (1869-1941), who approached the subject from his distinct perspective of conflict of laws, in a monumental four-volume treatise titled Internationales Verwaltungsrecht (International Administrative Law, 1910-1936). His life-time vision was the development of a new unified system of rules applicable to the transnational aspects of administrative law, to match the well-established conflict rules of private international law and procedure. And in the process, as part of an effort to demonstrate the pragmatic foundations of his approach in different sectors of public administration, he also assembled and analyzed a unique compendium of contemporary legal source materials that would indeed qualify today as typical ‘transnational environmental law’.
Chapter 8 in volume 2 of Neumeyer’s treatise (pp. 1-135), published in 1922, was headed Naturkräfte und Naturerzeugnisse (forces and products of nature). The first section, dealing with internationally shared water resources and water power, is based on the author’s earlier study of “water uses in international administrative law” (1915), criticizing the rigid territorial sovereignty principle invoked by the Austrian Administrative High Court in the notorious 1913 Leitha River case, and advocating the reciprocal protection of foreign legal interests along the lines of the 1909 US-Canadian Boundary Waters Treaty. Other sections deal with the transboundary regulation of mineral resources; agriculture, forestry, hunting and fishing (based in part on the author’s early practical experience as law clerk at a district court in the Bavarian-Austrian border region); and the management and conservation of marine living resources, including a discussion of the 1893 Bering Sea fur seals arbitration. Karl Neumeyer’s emphasis on the need for a mutual ‘other-regarding’ accommodation of foreign concerns, across the entire spectrum of nature-related topics, was way ahead of his times.
Neumeyer taught international law – with a focus on history and conflict of laws – at the University of Munich from 1901 onwards, until the Nazi regime forced him into retirement in 1934 because of his Jewish ancestry and barred him from continuing to work with the Hague Academy of International Law (where he had first lectured in 1923) and the Institut de Droit International (which had elected him to full membership in 1926). Ultimately, when he was notified of the impending eviction from his house and the confiscation of his library, he and his wife decided to commit suicide on 16 July 1941. There is a memorial tablet at their former home near the university; a Neumeyer-Strasse in the city; and in 2008, the Munich Law Faculty (whose dean he was in 1931-32) named the building that houses its Institute of International Law (which he had helped to create) in Karl Neumeyer’s honor and memory.While Neumeyer’s general conflict-of-laws approach to international administrative law did not find uniform acceptance in the literature, his re-discovered legacy in the environmental field survives in a modern metamorphosis labeled “international environmental administrative law” (internationales Umweltverwaltungsrecht), catalyzed not least by the emergence of the concept of “transnational administrative acts” in European Union law. More significantly perhaps, his poignant critique of the 1913 Leitha River case, and of its “territorial obsession” (staunchly perpetuated by the post-war reincarnation of the same court in the 1969 Salzburg Airport case and the 1991 Drava River case), has since been vindicated by a landmark decision of the German Federal Administrative Court in the 1986 Emsland case, granting residents of the Netherlands leave to appeal against the operating permit for a nuclear power plant on the Dutch-German border.
The first volume of the new Edward Elgar International Library of Law and the Environment series (2015) is dedicated to the memory of Karl Neumeyer. Appositely, it opens with one of his seminal essays written one hundred years ago, which in turn traced transnational European water law to its ancient Roman roots.
 Internationales Verwaltungsrecht (Munich: Schweitzer, vol. 1 1910, vol. 2 1922, vol. 3/I 1926, vol. 3/II 1930; Zurich: Verlag für Recht und Gesellschaft, vol. 4 1936). See also Karl Neumeyer, ‘Le droit administratif international’, Revue Générale de Droit International Public 18 (1911) 492-499 ; and id., ‘Internationales Verwaltungsrecht: Völkerrechtliche Grundlagen’, in J. Hatschek & K. Strupp (eds.), Wörterbuch des Völkerrechts und der Diplomatie (Berlin: de Gruyter, vol. 1 1924) 577-581.
 Karl Neumeyer, ‘Die Wassernutzung im internationalen Verwaltungsrecht’, Annalen des Deutschen Reichs für Gesetzgebung, Verwaltung und Volkswirtschaft (1915) 768-805.
 Kaiserlicher & Königlicher Verwaltungsgerichtshof (Vienna, 1 March 1913), Niemeyers Zeitschrift für Völkerrecht 7 (1913) 56; English translation in American Journal of International Law 7 (1913) 653-665.
 Treaty Relating to the Boundary Waters and Questions Arising Along the Boundary Between the United States and Canada (Washington/DC, 11 January 1909), American Journal of International Law 4 (Suppl. 1909) 239.
 Great Britain vs. United States (Paris, 15 August 1893), International Environmental Law Reports 1 (1999) 43; see vol. 2 of Neumeyer’s Internationales Verwaltungsrecht (supra note 1) at 121 n. 99, 125 and 131.
 Biography by Henriette v. Breitenbuch, Karl Neumeyer: Leben und Werk, 1869-1941 (Frankfurt: Lang, 2013).
 Obituaries and commemorative notes by Hans Wehberg, Friedenswarte 41 (1941) 256-260; Hans Morgenthau, American Journal of International Law 35 (1941) 672; Max Gutzwiller, Annuaire de l’Institut de Droit International (1947) 317-322, and id., Rabels Zeitschrift für ausländisches und internationales Privatrecht 27 (1963) 402-410; Klaus Vogel, Archiv des öffentlichen Rechts 95 (1970) 138-140, and id., ‘Karl Neumeyer: In den Tod getrieben’, in P. Landau & H. Nehlsen (eds.), Grosse jüdische Gelehrte an der Münchener juristischen Fakultät (Ebelsbach: Aktiv, 2001) 97-111. – Karl Neumeyer’s two sons had already emigrated to safety in the United States and Sweden, whereas the family of his elder brother Alfred, prominent judge and chairman of the Jewish Community in Munich, fled to Argentina in January 1941 and later settled in Israel; see the memoirs of Alfred Neumeyer Jr., Lichter und Schatten: Eine Jugend in Deutschland (Munich: Prestel 1967); and Alfred Neumeyer Sr., Alexander Karl Neumeyer & Imanuel Noy-Meir, Wir wollen den Fluch in Segen verwandeln: Drei Generationen der jüdischen Familie Neumeyer – eine autobiografische Trilogie (Berlin: Metropol 2007).
 For critical evaluations (all of which acknowledge Neumeyer’s “pioneering central contribution”), see Klaus Vogel, ‘Administrative Law: International Aspects’, in R. Bernhardt (ed.), Encyclopedia of Public International Law 1 (Amsterdam: North Holland, 1992) 22-27, at 24; Benedict Kingsbury, Nico Krisch & Richard B.Stewart, ‘The Emergence of Global Administrative Law’, Law and Contemporary Problems 68 (2005) 15-61, at 19 n. 9, and 28 n. 26; Franz C. Mayer, ‘Internationalisierung des Verwaltungsrechts’, in C. Möllers, A. Vosskuhle & C. Walter (eds.), Internationales Verwaltungsrecht: Eine Analyse anhand von Referenzgebieten (Tübingen: Mohr Siebeck, 2007) 49-71, at 54 n. 20, and 55; and Matthias Ruffert, ‘Perspektiven des Internationalen Verwaltungsrechts’, ibid. 395-419, at 398-399 and 417.
 Wolfgang Durner, ‘Internationales Umweltverwaltungsrecht‘, in Möllers et al. (supra note 8) 121-164.
 Matthias Rossi, ‘Europäisiertes internationales Umweltverwaltungsrecht’, ibid. 165-180.
 In the scathing terms of Georges Scelle, ‘Obsession du territoire’, in F.M. van Asbecke et al. (eds.), Symbolae Verzijl (The Hague: Nijhoff, 1958) 347-361.
 Freilassing Township & Max Aicher vs. Austrian Federal Ministry for Transport & State-Owned Enterprises, Verwaltungsgerichtshof (Vienna, 30 May 1969), case Z.233, 314/69, English summary by Peter H. Sand, Transnational Environmental Law: Lessons in Global Change (The Hague: Kluwer, 1999) 90-92.
 Slovenian Environmental Protection Agency vs. Austrian Federal Ministry for Agriculture & Forestry, Verwaltungsgerichtshof (Vienna, 29 January 1991), case 90/07/0174-3, English summary by Peter Fischer & Gerhard Loibl, Austrian Journal of Public and International Law 44 (1993) 243-245.
 Bundesverwaltungsgericht (Berlin, 17 December 1986), case 7 C 29.85, text in Archiv des Völkerrechts 25 (1987) 355-360; see Durner (supra note 9) at 153-155, characterizing the judgment as a paradigm shift.
 Note, however, that the appeal was eventually dismissed and the Emsland plant went into operation in 1988, even though it is now scheduled to close down in 2022, following the German government’s decision in 2011 to phase out all nuclear power production. See Peter H. Sand, ‘The Evolution of Transnational Environmental Law: Four Cases in Historical Perspective’, Transnational Environmental Law 1 (2012) 183-198, at 188.
 P.H. Sand (ed.), The History and Origin of International Environmental Law (Cheltenham/UK: Edward Elgar, 2015) 3-13: Karl Neumeyer, ‘A Contribution to International Water Law’, English translation of ‘Ein Beitrag zum Internationalen Wasserrecht’, Festschrift für Georg Cohn (Zurich: Orell Füssli, 1915) 143-166.