Editorial
How Progressive Nitrogen Limitation to Growth May Be Avoided in CO2-Enriched Air: A recent study in Soil Biology & Biochemistry points the way towards an answer.

Medieval Warm Period Record of the Week
This issue's Medieval Warm Period Record of the Week comes from Lapland (northern regions of Finland and Norway).

Subject Index Summary
Extinction (Real-World Observations - Animals: Amphibians): Earth's amphibians have suffered greatly over the past few decades, due to an emergent infectious disease; but there is no evidence that concurrent global warming has been a problem for them.

Journal Reviews
Aerosol Radiative Forcing of Climate: How well is it defined? ... and does the result matter much?

Summer Temperatures of Central Chile Back to AD 850: Do they reveal the presence of the Medieval Warm Period and Little Ice Age?

A 2000-Year Temperature History of the Indo-Pacific Warm Pool: What does it reveal about the nature of modern warmth?

Battling for Fungal Sporocarps in Earth's Forests: CO2 vs. O3: Which trace gas will prevail if their atmospheric concentrations continue their upward trajectories?

CO2 Effects on Indole-3-Acetic Acid in Ginkgo biloba Trees: What are they? ... and why are they important?