This fall the Senate may consider the Climate Stewardship Act of 2003, proposed by Sens. John McCain (R‑Ariz.) and Joseph Lieberman (D‑Conn.), which would cap carbon dioxide emissions in order to combat global warming. The effect of this legislation, even if it were applied to every nation that agreed to the Kyoto Protocol, would be too small for even the most sophisticated instrumentation to detect. Worse, the policy would impose serious economic costs and boost energy prices. This briefing examines the effects that CO2 emission caps have on climate under a variety of scenarios, ranging from United Nations’ projections to observationally based predictions. Michaels also will relate this risk to Europe’s recent heat-related deaths.