Environmental economics has mostly focused on micro issues pertaining to welfare and efficiency analysis. I develop a general framework to address short-run issues both for a closed economy and for an open one where emission permits are globally traded. Fiscal policy and emission permit issuance can both be used as short-run stabilization tools in a closed economy although the former is ineffective in a small open economy. In a large open economy, issuing emission permits in excess of international agreements remains an effective instrument, although it acts as a beggar-thy-neighbor policy, highlighting the crucial role of global monitoring on macroeconomic grounds.