Holliday et al.'s "comprehensive refutation" of the Younger Dryas impact hypothesis (YDIH) is a highly misleading Gish gallop. An earlier blog post addressed the presence of impact melts and microspherules in the YDB (Younger Dryas boundary). By themselves, they confirm a cosmic impact at Abu Hureyra near the YD onset. Due to the similarity of debris at the YDB across a wide range of sites, it's likely there were cosmic impacts across a wide area within a short timespan. Other blog posts examined the presence of nanodiamonds and platinum in the YDB. As they occur in the debris layer with microspherules at Abu Hureyra, they are also good impact indicators. They are present in many other YDB layers, along with apparent impact spherules, signalling a widely distributed cosmic impact. The previous blog post showed this layer of impact debris distributed across four continents within a narrow timeframe suggests a single event or highly correlated series of events wit...