Drought and drought-induced famine are recurring phenomena in Mesoamerica that have devastated populations in the region repeatedly during the past two millennia. Although it is counterintuitive to conceive of the idea that volcanic eruptions anywhere in the world might affect the lives of people in Mesoamerica, we examine the reports of drought and famine during the period A.D. 1440 to 1840 and compare them with known, large volcanic eruptions. We then apply non-parametric statistical techniques to determine whether the coincidences seen between worldwide volcanic eruptions and Mesoamerican drought within the following two years were due to random chance or whether there was a direct, mathematically verifiable correlation. We find a direct correlation to a probability of 56 in 100 million. We conclude that due to its unique geographical position, Mesoamerica was repeatedly devastated by drought and subsequent famine between 1440 and 1840 due to the indirect climatic effects of large volcanic eruptions that could be located anywhere in the world.

Recent paleoecological research indicates that the collapse of Classic Maya civilization in the southern and central Maya Lowlands coincided with the onset of prolonged and severe drought conditions around A.D. 850. The northern Maya Lowlands is an area that receives much less rainfall today and probably did so throughout most of the recent past; nevertheless, many northern lowland sites not only persisted throughout the period of the drought but actually prospered under the hegemony of Chichen Itza. This paper attempts to resolve this obvious paradox by examining the adaptive responses made by the northern Maya. The northern lowlands had a slight edge in adapting to the climate change that apparently devastated the south because it had easy access to a diversity of resources that no doubt contributed to Chichen Itza's subsistence security and the enrichment of its realm. However, massive transformations in the political and religious domains were every bit as necessary to Chichen Itza's adaptive strategy. The seeming paradox of Chichen Itza's successful adaptation to environmental adversity represents a cautionary tale about the dangers of oversimplification that are inherent in environmental deterministic thinking. Paradoxes of this kind arise when the primacy of cultural factors in adaptive processes is ignored.

Since the late 1950s, scientists have used sediment cores from lakes on the Yucatan Peninsula to explore the complex interactions among climate, environment, and ancient Maya culture. Early paleolimnological studies generally assumed that late Holocene climate was invariable. Consequently, paleolimnologically inferred environmental changes that occurred during the past 3,000 years or so—for example, forest decline and soil erosion—were attributed wholly to anthropogenic activities such as land clearance for agriculture and construction. Recent high-resolution, proxy-based paleoclimate records from continental and insular sites around the Caribbean Sea contradict the assumption of late Holocene climate stability. Instead, these core data suggest that regional drying began about 3,000 years ago and that the past three millennia were characterized by variable moisture availability. Paleoclimate inferences from Lakes Chichancanab and Punta Laguna, northern Yucatan Peninsula, indicate that drought events over the past 2,600 years were cyclical. These dry events, thought to have been driven by solar forcing, appear to have occurred approximately every two centuries (about 208 years). The driest period of the late Holocene occurred between A.D. 800 and 1000, coincident with the Classic Maya Collapse. We review the history of paleolimnological studies in the Maya Lowlands, discuss the difficulty of differentiating climatic signals from anthropogenic signals in late Holocene lake sediment profiles, and assess current understanding of past climate changes in the region based on regional lacustrine sediment studies.

The demographic and cultural Collapse of the ancient lowland Maya civilization in the ninth century A.D. has long been of fascination to both scholars and the general public. A large number of hypotheses has been offered to explain this event. Evidence derived from several independent lines of investigation during the 1990s indicates the time of the Maya Collapse was one in which severe drought conditions prevailed over much of the lowlands. Drought is now considered a potential primary causal factor for the Collapse. This paper cites some of the evidence for the presence of drought conditions at the time of the Collapse and then considers the degree to which a drought-based explanation for the Collapse is compatible with what is currently known about the Collapse's occurrence. There are problematic aspects to the temporal and spatial development of the Collapse that suggest that the Terminal Classic-period drought did not constitute a single, overwhelming blow that rendered collapse inevitable. It is suggested, instead, that culture-historical events and ecological factors interplayed with the Terminal Classic-period drought in such a way as to render the Collapse possible.

During the spring of 1998, an El Niño event produced harsh drought conditions in much of Mexico, including the Maya area. Similar events surely occurred in the distant past. This paper reports on investigation of chronological correlations between El Niño event sequences as suggested by glacial ice-core data from Quelccaya in the Peruvian Andes, historical-severity-ranked El Niño event sequences, and historical drought documentation for the Maya area. Positive correlations between Andean ice-core data sets and historical sequences were expected to provide evidence for earlier discrete El Niño event sequences as far back as A.D. 470 that could be used as proxy data to reconstruct annual El Niño events affecting southern Mesoamerica, including the Maya Classic through Postclassic periods. Correlations of these data sets proved inconclusive, suggesting the need for alternative approaches toward reconstructing discrete El Niño sequences for the Maya area.