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:
- Eons,
- Epochs,
- Eras,
- Periods,
- 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.