Context: Geologists have said that sediments at Crawford Lake in Canada’s Ontario have provided evidence of the beginning of the Anthropocene epoch. About Anthropocene epoch:
- It is a proposed geological epoch.
- Term coined by: Nobel Prize-winning chemist Paul Crutzen and biology professor Eugene Stoermer.
- What does it denote?: 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.
- Unwelcome changes: It is associated with 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.
- Estimated beginning of epoch: Members of the Anthropocene Working Group (AWG) have estimated that the new epoch started sometime between 1950 and 1954.
- Lack of consensus: There are disagreements within the scientific community regarding when it began, or has it already begun, or if they have enough evidence to prove its advent.
- Site of examination: 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.
- Advent: There are distinct and multiple signals starting around 1950 in the water body, which showed that the effects of humans overwhelm the Earth system.
- Destructive humanising of Earth: The presence of plutonium (due to detonation of nuclear weapons) indicates when humanity became such a dominant force that it could leave a unique global ‘fingerprint’ on Earth.
- Inconclusive evidence: These findings don’t mean that they have proved the advent of the Anthropocene epoch
- The geologic time scale is the “calendar” for events in Earth history.
- Subdivision: It subdivides all time into named units of abstract time called—in descending order of duration— eons, eras, periods, epochs, and ages.
- Methodology: The enumeration of those geologic time units is based on stratigraphy, which is the correlation and classification of rock strata.
- Fossil markers: The fossil forms that occur in the rocks, however, provide the chief means of establishing a geologic time scale, with the timing of the emergence and disappearance of widespread species from the fossil record.