States cannot yet consistently solve international environmental problems requiring cooperation. Some international environmental negotiations result in clear successes. Others seem to fail or simply flatline, failing to progress beyond initial modest progress, even when they apply the "lessons learned" from prior rounds of negotiation. Existing scholarship fails to fully explain this variation. This lack is particularly troubling given that major environmental negotiations often address serious, even existential threats that appear to require international cooperation to effectively address.Existing theory that attempts to explain negotiation success and failure focuses on a variety of factors: (1) the advancement of knowledge and structures for the dissemination of knowledge; (2) institutional features such as treaty design, particularly features designed to solve problems of collective action; (3) structural features of the issue area, such as the scope and complexity of the problem or the existing configuration of relevant interests at the domestic level; and (4) a variety of miscellaneous factors such as leadership.But even taken collectively, these existing lines of explanation do not coherently explain the variation seen even within two key issue areas, ozone and climate change. Many success factors seen in ozone were present in climate change as well, but failed to lead to success there. On the other hand, one real differentiator between ozone and climate - the greater difficulty of the climate problem - appears to explain negotiation outcome but does not make sense given that unilateral action has been possible at the domestic level. If climate change is simply too daunting to address, why have some states still engaged in significant unilateral regulation?A plausible answer lies in a process largely unutilized by previous scholarship on international negotiations: policy-industry feedback processes, which I refer to as the "green spiral." In such feedback processes, initial policy moves lead to adaptive industry responses, such as changes in capital investment. These adaptive responses actually change material industry interests, stimulating adaptation in existing "substitutable" industries that can adapt, growth in "winner" industries that benefit from regulation, and shrinkage in "loser" industries that bear high costs from regulation. In other words, these adaptive responses shrink coalitions against regulation, and grow coalitions for regulation. These changes in turn feed back into policymaking by increasing the political viability for international cooperation or regulation, allowing more regulation in the next round of negotiation or policymaking. More stringent regulation in the next round then triggers further industry reconfiguration; and so on, in a policy-industry feedback spiral.Green spiral processes do not always occur; and they may occur at the domestic level (as a feature of domestic policymaking) even when they do not occur at the international level. In this dissertation, I argue that their presence or absence at the international level explains the contrasting success and failure of the ozone and climate negotiations; and that the same dynamics explain variation at the national level seen within cases. In addition to characterizing these processes in ozone and climate, I explore the scope conditions for and policy implications of these processes in environmental negotiation and policymaking generally. Finally, I discuss the implications of this research project for existing and current scholarship.