The European Union Emissions Trading System (EU ETS) is the largest mandatory programme of its kind. The entitlements in emissions allowances (emissions entitlements) combine public and private law characteristics: allowances are tradable, commercially valuable regulatory instruments. This dual nature reveals a new interdependency between public and private law mechanisms in the context of climate change policy. This article argues that achieving the requisite level of emissions reductions is contingent on the viability of the emissions market, and that both are dependent on the definition of emissions entitlements. This view is supported by a case study which identifies the practical and serious consequences of the absence of a legal concept of emissions entitlements. The United States (US) Acid Rain Program offers useful lessons on the treatment of emissions entitlements. They can be further defined by analogy with similar rights regimes. Their nature is highly relevant to the emissions market, particularly to the commercial contracts that constitute it.

This article investigates the environmental and economic impact of the free allocation of emissions allowances in Emissions Trading Schemes (ETSs) as well as its compatibility with trade law. Free allocation can facilitate the industry’s gradual adjustment to an ETS and hence boost its acceptability. At the same time, however, the article shows that the economic and environmental benefits of free allocation are debatable. Moreover, the practice of free allocation possibly contravenes WTO law. The conclusion that free allowances may constitute an objectionable subsidy under WTO subsidy disciplines raises questions of law reform. Should the ETS be reformed to fit conventional trade imperatives, or should trade law be rethought so as to be responsive to contemporary environmental protection strategies? The article argues that, considering the questionable benefits of free allocation, any adjustment to trade law should be narrow and temporary.