This article should be merged into Milankovitch cycles. If you disagree with this request, please discuss it on the article's talk page. Small icon for merging articles File links The following pages link to this file: Friction Jacobin Private branch exchange Pro-feminist Rotary piston engine Tagalog language Saint Veronica Spoiler effect Parser Password length equation Sudovian language Wikipedia:Why arent these pages copy-edited Static scoping Maximum power theorem General... Milankovitch cycles is the name given to the collective effect of changes in the Earths movements upon its climate. ...

Orbital forcing, or Milankovitch theory, describes the effect on climate of slow changes in the tilt of the Earth's axis and shape of the orbit. These orbital changes change the total amount of sunlight reaching the Earth by up to 25% at mid-latitudes (from 400 to 500 watts per cubic meter at latitudes of 60 degrees). In this context, the term "forcing" signifies a physical process that affects the Earth's climate. Milutin Milanković (1879-1958) Milutin Milanković (a. ... Earth, also known as the Earth or Terra, is the third planet outward from the Sun. ... In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ...

This mechanism is believed to be responsible for the timing of the ice age cycles. A strict application of the Milankovitch theory does not allow the prediction of a "sudden" ice age (rapid being anything under a century or two), since the fastest orbital period is about 20,000 years. The timing of past glacial periods coincides very well with the predictions of the Milankovitch theory, and these effects can be calculated into the future. Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years For the animated movie, see Ice Age (movie). ...

Ice core data. Note length of glacial cycles averages ~100,000 years. Blue curve is temperature, green curve is CO₂, and red curve is windblown glacial dust (loess). Today's date is on the left side of the graph.

It is common to see it asserted that the length of the current interglacial temperature peak is similar to the length of the preceding interglacial peak (Sangamon/Eem), and from this conclude that we might be nearing the end of this warm period. However, this conclusion may be mistaken: the lengths of previous interglacials were not particularly regular (see graphic at right). Graph of Vostok CO2/T/dust from Petit 1999 paper. ... Graph of Vostok CO2/T/dust from Petit 1999 paper. ...

Note in the graphic the strong 120,000 year periodicity of the cycles, and the striking asymmetry of the curves. This asymmetry is believed to result from complex interactions of feedback mechanisms. It has been observed that ice ages deepen by progressive steps, but the recovery to interglacial conditions occurs in one big step.

The arrangements of land masses on the Earth's surface are believed to reinforce the orbital forcing effects. Comparisons of plate tectonic continent reconstructions and paleoclimatic studies show that the Milankovitch cycles have the greatest effect during geologic eras when landmasses have been concentrated in polar regions, as is the case today. Greenland, Antarctica, and the northern portions of Europe, Asia, and North America are situated such that a minor change in solar energy will tip the balance between year-round snow/ice preservation and complete summer melting. The presence of snow and ice is a well-understood positive feedback mechanism for climate. The tectonic plates of the world were mapped in the second half of the 20th century. ... The table and timeline of geologic periods presented here is in accordance with the dates and nomenclature proposed by the International Commission on Stratigraphy. ... World map showing location of Europe A satellite composite image of Europe Europe is geologically and geographically a peninsula, forming the westernmost part of Eurasia. ... World map showing location of Asia A satellite composite image of Asia Asia is the central and eastern part of the continent of Eurasia, defined by subtracting the European peninsula from Eurasia. ... World map showing location of North America A satellite composite image of North America North America is the third largest continent in area and in population after Eurasia and Africa. ... Positive feedback is a type of feedback. ...