And Then There Was Ice

This chapter introduces the basic definitions of a glacier and of the glaciosystem (a term coined by the author which refers to the glacier ecosystem). It describes glaciers, and through interactive links, shows the reader glaciers that can be viewed on a smart phone or computer. The chapter also describes the origin and formation of glaciers and their various functions. It introduces the life cycle of a glacier and also explains past and likely future ice ages (or glacial periods) as well as dynamics that may deepen global warming and impede the natural glacial age cycles, including the orbit of the Earth around the sun and its tilt and its relative influence on ice ages.

Pioneers of the Ice Age Models: A Brief History from Agassiz to Milankovitch

It is currently known that astronomical factors trigger the emergence of glacial and interglacial periods. However, nearly two centuries ago, the overall situation was not as apparent as it was with today’s scientists. In this article, I briefly discuss the astronomical model of ice ages put forward between the 19th and 20th centuries. This century was indeed annus mirabilis for scientists to understand the ice age phenomenon. Agassiz, Adhémar and Croll laid the foundation stones for understanding the dynamics of ice ages. But it was Milankovitch who combined empirical geology with mathematical astronomy. To put specifically, he identified the shortcomings of the preceding ice age models and modified his model accordingly. In what follows, I review former approaches to the ice age problem and show how they failed to meet their objectives. Next, I show how Milankovitch’s model managed to capture all sufficient astronomical elements. Last sections focus on Milutin Milankovitch’s genuine approach, including his accomplishment of tackling the problem mathematically.

Distribution of alpine endemic plants of northern Asia: a dataset

We describe a dataset providing information on the geographic distribution of northern Asian endemic alpine plants. It was obtained by digitising maps from the atlas “Endemic alpine plants of Northern Asia”. Northern Asia includes numerous mountain ranges which may have served as refugia during the Pleistocene ice ages, but there have been no studies that analysed this question. We suggest that this dataset can be applied for better understanding of the alpine endemism in northern Asia. The dataset includes 13709 species distribution records, representing 211 species from 31 families and 106 genera. Each record provides data regarding the distribution of an individual species. These data provide a foundation for studying northern Asia's endemic alpine species and conducting research on the factors concerning their distribution.

Earth Ice Age Dynamics: A Bimodal Forcing Hypothesis

The Earth has gone through multiple ice ages in the past million years. Understanding the ice age dynamics is crucial to paleoclimatic study, and is helpful for addressing future climate challenges. Though ice ages are paced by variations in Earth’s orbit geometry, how various climatic system components on the Earth respond to insolation forcing and interact with each other remains unclear. A prevailing view argues that the initial responses occur in the northern high latitudes (i.e. the northern high-latitude hypothesis, NHH). This opinion is challenged by recent reports, such as the lead of climate change in the Southern Hemisphere (SH) relative to that in the Northern Hemisphere (NH), the southern control on Atlantic meridional overturning circulations (AMOC), and the potential significance of Southern Hemisphere (SH). Alternatively, the tropical hypothesis (TH) argues for a leading role of the tropics. Both the NHH and the TH belong to a single-forcing mechanism, and have difficulty in interpreting phenomena, such as the saw-tooth pattern of the ice ages. Here we present a new proposal concerning the Earth’s ice age dynamics: the bimodal forcing hypothesis (BFH). The essential assumption of this hypothesis is that for glacial-interglacial cycles, the cooling (glaciation) starts from the northern high latitudes, whereas the warming (deglaciations) starts from the SH. Particularly, the BFH emphasizes the significance of SH oceans in accumulating and transferring heat for deglaciations. Thus, it is capable to reasonably explain the saw-tooth pattern. We compiled 100 paleotemperature records globally for validation. The BFH is consistent with most of these records, and provides a straightforward and comprehensible way to interpret ice age on Earth.

Biography of the Earth

The last era in the Phanerozoic Eon, the Cenozoic Era, is detailed in this chapter. The rise and radiation of the mammals occurred during Cenozoic after the devastation wrought by the Chicxulub Asteroid impact at the end of the Mesozoic Era. Ecological resources and niches vacated by the dinosaurs because of the mass extinction were filled by the mammals with concurrent developments in plants. Changes in climate and the mid-Miocene warming happened mid-era, then drying out and opening of grasslands followed by a plunge into ice ages and the Pleistocene extinction event. The late Cenozoic witnessed the development of humankind as the great ice sheets from the Pleistocene started to melt and the climate warm. The planet started to look similar to how it appears to humans today, and the current age of the Earth is the Cenozoic Era, Quaternary Period, Holocene Epoch, Meghalayan Age.

Exploring the Dramatic Shift in Ice Age Duration

Scientists are still seeking an explanation for the Mid-Pleistocene Transition when ice ages became longer in duration and exploring what it may mean for future climate change.