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  2. Season - Wikipedia

    en.wikipedia.org/wiki/Season

    A season is a division of the year [ 1 ] based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's tilted orbit around the Sun. [ 2 ][ 3 ][ 4 ] In temperate and polar regions, the seasons are marked by changes in the intensity of sunlight that ...

  3. Geologic Calendar - Wikipedia

    en.wikipedia.org/wiki/Geologic_Calendar

    The Geologic Calendar is a scale in which the geological timespan of the Earth is mapped onto a calendrical year; that is to say, the day one of the Earth took place on a geologic January 1 at precisely midnight, and today's date and time is December 31 at midnight. [1] On this calendar, the inferred appearance of the first living single-celled ...

  4. Geologic time scale - Wikipedia

    en.wikipedia.org/wiki/Geologic_time_scale

    The geologic time scale, proportionally represented as a log-spiral with some major events in Earth's history. A megaannus (Ma) represents one million (10 6) years. The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses ...

  5. Timeline of glaciation - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_glaciation

    Timeline of glaciation. There have been five or six major ice ages in the history of Earth over the past 3 billion years. The Late Cenozoic Ice Age began 34 million years ago, its latest phase being the Quaternary glaciation, in progress since 2.58 million years ago. Within ice ages, there exist periods of more severe glacial conditions and ...

  6. Cosmic Calendar - Wikipedia

    en.wikipedia.org/wiki/Cosmic_Calendar

    The Cosmic Calendar is a method to visualize the chronology of the universe, scaling its currently understood age of 13.8 billion years to a single year in order to help intuit it for pedagogical purposes in science education or popular science. In this visualization, the Big Bang took place at the beginning of January 1 at midnight, and the ...

  7. List of periods and events in climate history - Wikipedia

    en.wikipedia.org/wiki/List_of_periods_and_events...

    500 million years of climate change Ice core data for the past 400,000 years, with the present at right. Note length of glacial cycles averages ~100,000 years. Blue curve is temperature, green curve is CO 2, and red curve is windblown glacial dust (loess). Scale: Millions of years before present, earlier dates approximate.

  8. Greenhouse and icehouse Earth - Wikipedia

    en.wikipedia.org/wiki/Greenhouse_and_icehouse_Earth

    An illustration of ice age Earth at its glacial maximum. A "greenhouse Earth" is a period during which no continental glaciers exist anywhere on the planet. [6] Additionally, the levels of carbon dioxide and other greenhouse gases (such as water vapor and methane) are high, and sea surface temperatures (SSTs) range from 28 °C (82.4 °F) in the tropics to 0 °C (32 °F) in the polar regions. [7]

  9. Solar activity and climate - Wikipedia

    en.wikipedia.org/wiki/Solar_activity_and_climate

    Solar activity and climate. Solar irradiance (yellow) plotted with temperature (red) since 1880. Patterns of solar irradiance and solar variation have been a main driver of climate change over the millions to billions of years of the geologic time scale. Evidence that this is the case comes from analysis on many timescales and from many sources ...