Scenarios to Explore Greenhouse Decisions

The potential consequences of global climate change are disastrous. Anyone above a subsistence level of income cannot help thinking about the consequences of human activities that could make the Earth an inhospitable place.

Unfortunately, uncertainties about the consequences of our actions are as large consequences. The climate effects of greenhouse gas emissions is largely unknown. as well as bad, e.g., moderate warming could be enormously beneficial, particularly one of the periodic ice ages. as the potential Climate change could be good if the Earth is headed toward

I focus on what governments should be doing in response to the threat of anthropogenic global climate change. I propose to cut through the complexities of uncertainty by focusing on three essential areas for policy: (1) The relationship between emissions of greenhouse gases and global change climate. (2) The resulting effects on humans and the environment we ca~e about. And (3) the costs of reducing greenhouse gas emissions. To keep the analysis simple and transparent, I explore these three areas in a few "scenarios." The resulting analysis eliminates the myriad unessential detail that has prevented a clear view of what current policy should seek to accomplish. But the reader should be warned: caveat emptor.