Our understanding of how plant communities will respond to current and future climate change has advanced considerably since the use of early climate models to predict specific local temperature and precipitation changes, and thereby plant transitions, at the beginning of climate change recognition and research. The collection, availability and spatial distribution of pollen records across the Americas has recently allowed us to investigate plant compositional transitions during climate change periods in the past. Results from these models and pollen record investigations have provided formulated hypotheses, led by László Orlóci, in palynology and climate change ecology predicting that high latitude, high elevation and species-rich communities have shown greater plant compositional transitions during periods of climate change in the past, show greater change today, and will show greater change in the future. To address hypotheses for the past, and infer changes for the future, we used 238 pollen records across North and South America to test if latitude, elevation and taxa richness defined plant compositional transitions and their rates of change over the past 10,000 years, representing the majority of the Holocene (11.7k — 150 ybp), and if transitions were identifiable as hotspots of change. Contradicting Orlóci’s hypothesis we found low latitude records to show greater transitions during the late Holocene, associated with increased aridity leading to Amazon, deciduous and Atlantic forest — Caatinga, Cerrado shifts at low latitudes. Higher elevations showed greater plant compositional transitions during the late Holocene, providing support for Orlóci’s hypothesis of greater plant transitions at higher elevations, associated with Andean cooling over the past 5k years. Richness explained less of plant compositional transition than latitude and elevation and showed positive, negative and no relationships showing no clear conclusive pattern. Climate change research solely at high latitudes and high elevations overlooks consequences of climate shifts on other ecosystems, such as tropical forests of north-eastern South America showing past increased aridity and predicted future drought probability of 80% by 2050 leading to predicted 20% forest loss by the end of the century.