Access to information is the first "pillar" of the Aarhus Convention on Access to Information, Public Participation in Decision-Making and Access to Justice in Environmental Matters (1998). This article examines how the information disclosure obligations on states within the Aarhus Convention express a particular blend of human environmental rights, conjoining procedural entitlements (and duties) with a substantive right to an environment adequate to human health and well-being. "Aarhus environmental rights" have been lauded for increasing citizen access to environmental information, helping to secure more transparent and accountable regulatory processes. However, the information rights are rendered inconsistent in practice by three properties: 1) the discretion accorded to Convention Parties in interpreting Aarhus rights; 2) the exclusion of private entities from mandatory information disclosure duties; and 3) the indeterminate coupling of procedural and substantive rights. These tensions reflect a structural imbalance in the articulation of Aarhus rights between social welfare and market liberal perspectives. (c) 2010 by the Massachusetts Institute of Technology.