Editorial
Seventeen Years of Enriching Sour Orange Trees with CO2: What was learned from the longest such tree experiment conducted to date?

Medieval Warm Period Record of the Week
This issue's Medieval Warm Period Record of the Week comes from the Florida Everglades, USA.

Subject Index Summary
Hurricanes (Pacific Ocean): How much more frequent and powerful have they become, now that the earth has recovered from the global chill of the Little Ice Age?

Journal Reviews
The ABCs of Global Warming: The temperature rise is not all due to greenhouse gases.

1400 Years of Climate Variability in the Gulf of Mexico: Closing in on a solar-induced global Medieval Warm Period at least as warm as today.

The Progressive Nitrogen Limitation Hypothesis: An important new analysis of four forest FACE studies proves the concept's undoing.

Forest Response to Predicted CO2-Induced Climate Change in the Tianshan Mountains of China: What are the individual growth enhancements provided by the predicted changes in CO2, temperature, and precipitation? ... and what is the overall response to the simultaneous increases in all three factors?

Effects of Rising Atmospheric CO2 Concentrations on Growth and Nitrogen Fixation in Trichodesmium: What are they? ... and what are their implications?