Introduction

Recent decades have seen a remarkable proliferation of sophisticated and innovative legal arrangements to protect the global environment; yet major pressures on the biosphere and its alarming rate of deterioration continue largely unabated. Not surprisingly, enforcement is therefore considered an Achilles’ heel of international environmental law. The current regime lacks a central, overarching body to ensure enforcement; instead relying on domestic compliance by the very nations it seeks to commit.

Climate governance is no exception. The mitigation of climate change is a prime example of a collective action problem. It reveals the precarious balance between strong commitments and effective enforcement: efforts to achieve safe greenhouse gas concentrations in the atmosphere will fail unless there is a means of coercion or an incentive that is unavailable to non-participants. Yet, aside from the relatively limited options provided by the law of state responsibility, sovereign states cannot be coerced without prior consent. In turn, the expectation of strict enforcement may undermine their willingness to enter into meaningful substantive commitments. If the international community decides to intensify its cooperative efforts with deeper and more ambitious commitments, enforcing the latter will become an ever greater challenge.