Macroeconomic theory and policy are strongly based on the assumption that economic growth is a fundamental goal. The environmental realities of the twenty- first century compel a reassessment of macro theory in terms of the impact of current growth patterns on planetary ecosystems. This paper examines the macroeconomic impacts of growth in terms of several major areas of conflict between economic demands and ecosystem capacities: (1) energy use and fossil fuel dependence (2) greenhouse gas emissions and climate change (3) transportation systems and automobile use (4) food systems and agricultural productivity (5) water, forests, and fisheries (6) toxic chemicals and wastes. Implications for macroeconomic theory include a modification of the...