Scientists say the ‘Anthropocene epoch’ began in the 1950s: What it means, significance

  • July 13, 2023
  • Posted by: OptimizeIAS Team
  • Category: DPN Topics
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Scientists say the ‘Anthropocene epoch’ began in the 1950s: What it means, significance

Subject :Environment

Section: International conventions

Context:

  • In a major development that could change the Earth’s official geological timeline, geologists have said sediments at Crawford Lake in Canada’s Ontario have provided evidence of the beginning of the Anthropocene epoch — a proposed geological epoch that began when human activity started to have a significant impact on the Earth.

Details:

  • Anthropocene Working Group (AWG) have estimated that the new epoch started sometime between 1950 and 1954.
  • They revealed the findings after analysing the lake’s bottom sediments, which have over the years captured the fallouts of large-scale burning of fossil fuels, explosion of nuclear weapons and dumping of plastic and fertilisers on land and in water bodies.
  • The data show a clear shift from the mid-20th century, taking Earth’s system beyond the normal bounds of the Holocene (the epoch that started at the end of the last ice age 11,700 years ago).
  • Anthropocene Working Group (AWG):
    • It is a group of geologists who have been working since 2009 to make the Anthropocene part of the planet’s time scale.

What is the Anthropocene epoch?

  • The term was first coined by Nobel Prize-winning chemist Paul Crutzen and biology professor Eugene Stoermer in 2000.
  • It denotes the present geological time interval, in which the Earth’s ecosystem has gone through radical changes due to human impact, especially since the onset of the Industrial Revolution.
  • There are numerous phenomena associated with this epoch, such as:
    • Global warming,
    • Sea-level rise,
    • Ocean acidification,
    • Mass-scale soil erosion,
    • The advent of deadly heat waves,
    • Deterioration of the biosphere and other detrimental changes in the environment.
  • Many of these changes will persist for millennia or longer and are altering the trajectory of the Earth System, some with permanent effect.
  • They are being reflected in a distinctive body of geological strata now accumulating, with the potential to be preserved into the far future.

What have the geologists found?

  • The 79 feet deep and 25,800 square-foot-wide Crawford Lake was chosen for examination as its layers of sediment preserved the annual impact of human activities on the Earth’s soil, atmosphere and biology.
  • There are distinct and multiple signals starting around 1950 in the water body, which showed that “the effects of humans overwhelm the Earth system”.
  • The presence of plutonium (due to the detonation of nuclear weapons) gives a stark indicator of when humanity became such a dominant force that it could leave a unique global fingerprint’ on our planet.
  • Approval: A final approval might come at the 37th International Geological Congress in Busan, South Korea, which will take place next year

Earth’s geological time:

  • The modern geologic time scale was formulated in 1911 by Arthur Holmes.
  • A representation of time based on Earth’s rock record is called the geologic time scale.
  • The planet’s geological time scale is divided into five broad categories:
    1. Eons,
    2. Epochs,
    3. Eras,
    4. Periods,
    5. Ages.
  • While eon is the broadest category of geological time, age is the smallest category.
  • Each of these categories is further divided into sub-categories. For instance, Earth’s history is characterised by four eons, including Hadeon (oldest), Archean, Proterozoic, and Phanerozoic (youngest).
  • As of now, we’re in the Phanerozoic eon, Cenozoic era, Quaternary period, Holocene epoch and the Meghalayan age.

On what basis these categories are divided?

  • According to the New York-based Paleontological Research Institution, a variety of event categories are used to determine the division dates of the numerous eons, eras, periods, epochs, and ages. These occasion categories comprise, but are not restricted to:
    • The first occurrence of a species: All biological forms are included in this (plants, animals, bacteria, etc). The “first of first” species are of particular interest (e.g., the first oxygen-breathing organism, the first seed-producing plant, and so on).
    • Key species going extinct or catastrophic extinctions: A huge number of species going extinct in a short period of geologic time is known as a mass extinction. The Cretaceous-Paleogene extinction event, when most dinosaur species became extinct, is a well-known illustration of mass extinction.
    • Major worldwide climate shifts: when the climate significantly diverges from the average for the time, as during ice ages.
    • Supercontinental formation and/or breakup: When all significant landmasses on the surface of the Earth combine to form one landmass, supercontinents are created.
    • Catastrophic events: Major catastrophes can result in or set off other occurrences like extinctions and climate change. Major floods, meteorite impacts, and volcanic eruptions are examples of catastrophic catastrophes.
    • Global magnetic polarity shifts: The planet’s magnetic polarity “flips” on an irregular basis, with the North pole switching places with the South pole.
Environment Scientists say the ‘Anthropocene epoch’ began in the 1950s: