Making accurate predictions of the effects of global change on ecosystems and the organisms that inhabit them has become an important goal for ecologists. Experimental and modeling approaches aimed at understanding the linkages between factors of global change and biotic responses have become numerous and increasingly complex in order to adequately capture the multifarious dynamics associated with these relationships. Constrained by resources, experiments are often conducted at small spatiotemporal scales and at low organizational levels, although some studies have shown that responses at higher levels can be dissimilar. This is especially true for differences between ecological responses to the presence and absence of global change factors, commonly referred to as effect size. Prominent examples include changes in effect size or even a sign reversal as experiments continue over many years or decades, or patterns of decreasing effect size with increasing level of organization (e.g. from leaf to tree). There is an urgent need to synthesize this complexity and to quantify effect sizes and over-arching trends that are valid across large spatial, temporal and organizational dimensions. Studies presented will include discussions of: - evaluating the fit between global models and local causation - the acclimation or downregulation of responses to global change across time - portfolio effects and overyielding effects across organizational scales - effectiveness of top-down vs. bottom-up approaches in global change studies - local vs. global mitigation of global change impacts - how to best integrate assessments of global change across scales