Editorial
The Costs of Free Energy: Like the "free lunch," free energy is not exactly what it's made out to be.

Medieval Warm Period Record of the Week
This issue's Medieval Warm Period Record of the Week comes from the Jinchuan Peat Marsh, Huinan County, Jilin Province, China

Subject Index Summary
Ocean Acidification (Effects on Marine Animals: Miscellaneous): A hodge-podge of miscellaneous sea creatures have been scrutinized for their responses to "ocean acidification." What do the studies reveal?

Journal Reviews
Greenland Temperatures of the Past Millennium Based on Nitrogen and Argon Isotopic Ratios: An impressive new study testifies to the reality of the Medieval Warm Period and Little Ice Age.

The Naturally Oscillating Climate of Northern Norway: Fjord sediments reveal the four major cool and warm periods of the last 1500 years.

The Temperature Sensitivity of Global Biospheric Respiration: Terrestrial ecosystem respiration was long believed to increase strongly with temperature; but that is now believed no longer.

The Power of Acclimation: How Trees Respond to Warming in Natural Settings: Are the air temperatures at which different tree species optimally photosynthesize firmly fixed? ... or can they adjust their physiology to accommodate a modest warming? ... or maybe even a warming of the magnitude predicted by the world's climate alarmists?

The Effects of Warming on Alpine Vegetation in the Swiss Alps: They wouldn't be negative, would they?