Constraining the role of climate change as an ecological process

Paleoecologists have long debated the role of climate change in shaping ecosystem change. We do so because climate change is the single most important factor in shaping the fossil record of the last 11,000 years. Anticipating future ecosystem changes in coming decades, however, requires adopting systematic approaches, developing high levels of temporal and taxonomic resolution in fossil records, and abandoning qualitative or relative indices of past climate conditions in favor of new well-calibrated approaches. Examples from eastern North America show that quantified reconstructions of multiple climate variables combined with detailed species' level data are essential for testing ecological hypotheses.