Implications of global climate change for Southern forests: Can we separate fact from fiction?This article is part of a larger document. View the larger document here.
There is no scientific dispute regarding the existence of a greenhouse effect. There is no doubt that water vapor, carbon dioxide (CO2), and methane concentrations are greenhouse gases. The data showing increases in CO2 in the atmosphere are incontrovertible. Uncertainties arise when the Earth's biological responses to climate change are to be quantified. Such uncertainties can be compounded when the responses of ecosystems, especially forests, are to be delineated. Complex interactions among effects of climate change, disturbance, competition, invasive species, management intervention, land use change, and other actions must be clarified by modeling. Model development has improved greatly, but evaluation and validation remain difficult. Model outputs for the South show a fairly wide range of potential changes under scenarios developed from different climate models, suggesting that the assumption of steadystate conditions has little likelihood of occurrence. This implies that we should rethink management approaches, design research to include new ecosystem variables, and seek integrated ecosystem knowledge on scales heretofore rarely treated.