Paleoclimate in the context of "Earth's history"

Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS), are alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data derived from deep sea core samples. Working backwards from the present, which is MIS 1 in the scale, stages with even numbers have high levels of oxygen-18 and represent cold glacial periods, while the odd-numbered stages are lows in the oxygen-18 figures, representing warm interglacial intervals. The data are derived from pollen and foraminifera (plankton) remains in drilled marine sediment cores, sapropels, and other data that reflect historic climate; these are called proxies.

The MIS timescale was developed from the pioneering work of Cesare Emiliani in the 1950s, and is now widely used in archaeology and other fields to express dating in the Quaternary period (the last 2.6 million years), as well as providing the fullest and best data for that period for paleoclimatology or the study of the early climate of the Earth, representing "the standard to which we correlate other Quaternary climate records". Emiliani's work in turn depended on Harold Urey's prediction in a paper of 1947 that the ratio between oxygen-18 and oxygen-16 isotopes in calcite, the main chemical component of the shells and other hard parts of a wide range of marine organisms, should vary depending on the prevailing water temperature in which the calcite was formed.

The fauna of Madagascar is a part of the wildlife of Madagascar.

Madagascar has been an isolated island for about 70 million years, breaking away from Africa around 165 million years ago, then from India nearly 100 million years later. This isolation led to the development of a unique endemic fauna.

Eldgjá (Icelandic pronunciation: [ˈɛltˌcauː] , "fire canyon") is a volcano and a canyon in Iceland. Eldgjá is part of the Katla volcano; it is a segment of a 40 kilometres (25 mi) long chain of volcanic craters and fissure vents that extends northeast away from Katla volcano almost to the Vatnajökull ice cap. This fissure experienced a major eruption around 939 CE, which was the largest effusive eruption in recent history. It covered about 780 square kilometres (300 sq mi) of land with 18.6 cubic kilometres (4.5 cu mi) of lava from two major lava flows.

While Icelandic records about the effects of the eruption are sparse, paleoclimate proxies and historical records from China, Europe and the Islamic world describe widespread impacts on the Northern Hemisphere's climate. The Eldgjá eruption produced a noticeable cooling of the climate, with resulting cold winters and food crises across Eurasia.

Environmental magnetism is the study of magnetism as it relates to the effects of climate, sediment transport, pollution and other environmental influences on magnetic minerals. It makes use of techniques from rock magnetism and magnetic mineralogy. The magnetic properties of minerals are used as proxies for environmental change in applications such as paleoclimate, paleoceanography, studies of the provenance of sediments, pollution and archeology. The main advantages of using magnetic measurements are that magnetic minerals are almost ubiquitous and magnetic measurements are quick and non-invasive.

The Bølling–Allerød Interstadial (Danish: [ˈpøle̝ŋ ˈæləˌʁœðˀ]), also called the Late Glacial Interstadial (LGI), was an interstadial period which occurred from 14,690 to c. 12,890 years Before Present, during the final stages of the Last Glacial Period. It was defined by abrupt warming in the Northern Hemisphere, and a corresponding cooling in the Southern Hemisphere, as well as a period of major ice sheet collapse and corresponding sea level rise known as Meltwater pulse 1A. This period was named after two sites in Denmark where paleoclimate evidence for it was first found, in the form of vegetation fossils that could have only survived during a comparatively warm period in Northern Europe. It is also referred to as Interstadial 1 or Dansgaard–Oeschger event 1.

This interstadial followed the Oldest Dryas period, which lasted from ~18,000 to 14,700 BP. While Oldest Dryas was still significantly colder than the current epoch, the Holocene, globally it was a period of warming from the very cold Last Glacial Maximum, caused by a gradual increase in CO₂ concentrations. A warming of around 2 °C (3.6 °F) had occurred during this period, nearly half of which had taken place during its last couple of centuries. In contrast, the entire Bølling–Allerød Interstadial experienced very little change in global temperature. Instead, the rapid warming was limited to the Northern Hemisphere, while the Southern Hemipshere had experienced equivalent cooling. This "polar seesaw" pattern had occurred due to the strengthening of the Atlantic meridional overturning circulation (and the corresponding weakening of the Southern Ocean overturning circulation). These changes in thermohaline circulation had caused far more heat to be transferred from the Southern Hemisphere to the North.