Toward Integrated Reconstruction of Past Climates

Reconstructions of past climates rely to a large extent on the difficult interpretation of climate proxies such as tree rings, ice cores, and sediments. In their Perspective, Trenberth and Otto-Bliesner argue that important issues such as the seasonality of past climate and changes in large-scale climate patterns such as the El NiA±o-Southern Oscillation (ENSO) can only be resolved if climate modelers and paleoclimate experts work closely together. They warn that conclusions about changes in ENSO from records that do not resolve interannual variability are especially fraught with difficulty.