As the earth’s environment changes with the alteration of important putative environmental drivers (e.g., CO2, temperature, nitrogen deposition, biotic invasions, and the frequency and severity of extreme weather events), ecologists and environmental biologists are scrambling to predict what the world may look like under these new conditions. To accomplish this goal, these scientists often use experimental manipulations of the most likely drivers of community and ecosystem change, particularly CO2, temperature, and nitrogen (e.g., Bergner et al. 2004, Mohan et al. 2006, Reich et al. 2006a). But are these relatively small-scale experiments enough to give us an accurate picture of the structure and function of a future world and is there a way to test their predictions?