According to geological time scale, we are now living in the Holocene epoch, an interglacial period started about 12,000 years ago after the retreat of Pleistocene glaciers. The relative stability of this period, warming up of the earth and moist soils helped in developing agriculture in different parts of the world. This eventually led to a more sedentary lifestyle, the development of villages and cities, and the creation of complex civilisations, in which we live today.
It is difficult to convert dates of events as described in ancient Indian texts to fit into the modern calendar. Most of the events have been dated according to planetary positions, which occurred at that time. One has to go back in time and look for occurrence of such planetary positions and make an intelligent guess to arrive at a possible date according to modern calendar. Often the original authors of these texts are unknown or mired in allegory, and the texts have been rewritten, enlarged and modified by different authors during different ages. It is difficult to separate facts from myths.
According to ancient Indian calendar the Vaivasvata (7th) Manvantara (8500 BC to 3492 AD) is equated with geological Holocene epoch. Two events mark the beginning of Kaliyuga. (1) The death of lord Krishna and (2) Coronation of Parikshit as the king of Hastinapur. All the ‘Puranas’ are unanimous with these events as the zero year of the Kaliyuga era.
The astrological positions ascribed to these events translate into the morning of Friday, the18th February, 3102 BCE as the beginning of Kaliyuga era.
After the death of lord Krishna the previous day, Yudhistira abdicated and renounced the world with all his brothers and made Parikshit, the grandson of Arjuna (son of Abhimanyu and Uttara), as the first king of Kaliyuga. Abhimanyu had been killed by Aswathama in the Mahabharata war, which was fought in 3138 BCE. Parikshit, who was conceived earlier, was born after the death of his father.
The end of Kaliyuga is predicted to be in 3492 AD, with the end of Vaivasvata (7th) Manvantara (which as stated earlier is equated with Holocene epoch). Human pressure on the earth system points to an earlier end of the Holocene epoch.
In the geological time scale, there have been five mass extinctions, when more than 75 per cent of species disappeared as environment of earth changed for the worse and did not support the existing life forms. The first mass extinction took place about 444 million years ago due to onset of severe ice age and 86 per cent of the existing dominant life forms were killed. The second mass extinction took place about 375 million years ago due to lack of oxygen in the atmosphere and 75 per cent of existing life forms vanished. The third mass extinction took place about 251 million years ago due to poisoning of the earth’s atmosphere with carbon dioxide, hydrogen sulfide, methane etc, ocean acidification, and increase in global temperature killing 96 per cent of existing life forms. The fourth mass extinction occurred 200 million years ago due to unknown reasons. The most recent, 5th mass extinction took place about 66 million years ago, when a huge meteorite with a radius of about 10 km crashed on the earth and made a crater with 180 km diameter and 20 km deep in Yukatan peninsula, Mexico. The impact created a doomsday scenario. Superheated dust particles and steam filled the sky preventing sunlight to reach earth for decades killing plant life as they could not carry out photosynthesis. Many volcanoes around the earth became active and spewed lava. There were super-tsunamis drowning land animals and plants. The atmosphere of earth became unsuitable to support most of the existing life forms, leading to the extinction of Dinosaurs.
Is the 6th mass extinction imminentIJ According to Global Footprint Network, it now takes the Earth one year and six months to regenerate the resources consumed by human beings in a year. By the 2030s, we will need the equivalent of two Earths to support us but we have only one.
We have exhausted 40 per cent of the known oil reserves, altered use of nearly 50 per cent of the land, and appropriated more than half of all accessible fresh water apart from polluting the atmosphere with increasing release of Green House Gases (GHG). The concentration of GHG’s (primarily carbon dioxide) has increased to 485ppm in 2015 as against the safe limit of 350ppm. This has resulted in increased ‘Radiative forcing’, which is a measure of change in the average amount of solar energy absorbed per square meter of the Earth’s area. It is now 2.97 Watts per square meter as against the boundary value of 1 W/sq m. This has caused unusual warming of the earth and increase in global temperature. The year 2016 is considered as the hottest year since global temperature has been recorded. If the present trend continues the global temperature may increase by 4.8 C by the end of 21st century.
Dominance of human beings on the earth system without caring for the survival of other forms of life is responsible for 93per cent loss of biodiversity. Species are currently disappearing about 100 times faster than the background rate normally seen between mass extinctions. Many other parameters, which sustain the delicate balance of the earth system such as, use of bio-geo-chemicals, ocean acidification, ozone depletion etc. have crossed boundary values and indicate serious worsening of the environment of earth. Environmental scientists warn this may trigger abrupt environmental changes that would be catastrophic for human beings (Sir Nicholas Stern, UK, 2007 and Johan Rockstrom and his group, Sweden, 2009).
According to a paper published by Richard Monastersky in the prestigious Journal, Nature in 2014, the 6th mass extinction is likely to happen by the year 2200 AD unless we take care of the earth system, make sustainable use of its resources and take care of all forms of life, which are also integral part of it. We may not have to wait until 3492 AD, when Kaliyuga of the 7th Manvantara is predicted to end.
Calculating three generations per century, the 7th generation from us will be the casualty in 2200 AD!
We are the first generation in the Holocene epoch with widespread knowledge of how our activities are influencing the Earth system. We need to achieve effective planetary stewardship. Otherwise it will be a one-way trip for humanity to an uncertain future in a new, but very different state of the Earth system (Will Steffen and his group, Australia, 2011).
(Dr Mitra is a former Dean, College of Agriculture and former Professor and Head, Department of Soil Science and Agricultural Chemistry, Orissa University of Agriculture & Technology)