Prof. Ashok Kumar Ghosh
Eco-Scope Bihar
“The Tipping Point – Alarming signals for life on Earth”
By Prof. Ashok Kumar Ghosh
Earth is an exquisitely beautiful planet, washed in water and surrounded by a thin atmosphere with swirling white clouds. This planet is a system of moving gas, liquid, and solids with numerous interconnected and interdependent components. Earth operates as a constantly changing dynamic system since its origin. Changes are going on in its physical as well as biological characteristics. It has gone through change in temperature – sometimes we talk of global warming and sometimes of ice age. The last ice age was 20.000 years ago. There may be controversy about the rate of change in Earth dynamic system, but it is accepted that changes have been accelerated by anthropogenic activities. The changes in recent times have become very fast and it is a big concern of all the persons related to environmental studies. It is a big question that whether the human beings, and everything else that lives on the Earth can adapt to this change, because the Earth, it turns out, is changing very, very fast .It is estimated that if the current rate of growth in human population, urbanization and our life style remains the same, seven Earths will be required to sustain life at the end of this century – unfortunately we have only one till date, and we do not expect origin of any new Earth in near future to share the load.
Human activity now dominates 43 percent of Earth’s land surface and affects twice that area. One-third of all available fresh water is diverted to human use. A full 20 percent of Earth’s net terrestrial primary production, the sheer volume of life produced on land every year, is harvested for human purposes. Extinction rates compare to those recorded during the demise of dinosaurs and average temperatures will likely be higher in 2070 than at any point in human evolution. Scientists informally call our current geological age the “Anthropocene,” and this means we’re strong enough to tip the planet, radically changing regional climates and ecologies.
Human population has quadrupled just in the past century, and today we add around 77 million people a year — an increase that is three orders of magnitude higher than the average yearly growth humanity experienced as recently as 400 years ago. We’ve converted 43% of the Earth’s land to agricultural or urban landscapes — with farms taking up most of that space — and even the remaining territory tends to be crisscrossed by roads. That’s a larger amount than the 30% of the Earth’s surface that went from being covered by ice to being glacier-free at the end of the last ice age.
There were 147 glaciers in Glacier National Park located in US state of Montana 150 years ago. Today only 37 glaciers remain healthy and scientists say they will likely completely melt by the year 2030. Similarly; glaciers all across Alps are retreating and disappearing every year. Gangotri Glacier, situated in the Uttarkashi District of Garhwal Himalaya is also sending alarming signals. Currently 30.2 km long and between 0.5 and 2.5 km wide, Gangotri glacier is one of the largest in the Himalaya. Gangotri has been receding since 1780, although studies show its retreat quickened after 1971. Over the last 25 years, Gangotri glacier has retreated more than 850 meters, with a recession of 76 meters from 1996 to 1999 alone.
We’ve increased the atmospheric concentration of carbon dioxide by more than a third, we’ve made the oceans more acidic and we’ve presided over the disappearance of so many species that many scientists believe we’re living through the sixth great wave of extinctions All of these changes are speeding up, not slowing down. In the last few decades, scientists have found tipping behaviors in various natural environments, from locale-scale ponds and coral reefs to regional systems like the Sahara desert, which until 5,500 years ago was a fertile grassland. So it seems that we are nearing a tipping point which will become irreversible. A research article published in Nature on 6th June, 2012 mentions that current trends suggest that half the Earth’s land surface will be disturbed by human activity by 2025 — and that could represent the point of no return for a livable planet. “Looking into the past tells us unequivocally that, yes, it can really happen.
Human activity now dominates 43 percent of Earth’s land surface and affects twice that area. One-third of all available fresh water is diverted to human use. A full 20 percent of Earth’s net terrestrial primary production, the sheer volume of life produced on land every year, is harvested for human purposes. Extinction rates compare to those recorded during the demise of dinosaurs and average temperatures will likely be higher in 2070 than at any point in human evolution.
Planet Earth (Source:NASA)
According to Dr.Anthony Barnosky, a professor of integrative biology at the University of California-Berkeley and a lead author of the paper published in Nature “The evidence makes it pretty clear that another critical transition or tipping point is very plausible within the next century. He joined a group of 17 other scientists to warn that this new planet might not be a pleasant place to live. There is already reference of “tipping point,” as a result of human activity like agriculture and urbanization. Researchers warn that the world is headed toward a tipping point marked by extinctions and unpredictable changes on a scale not seen since the glaciers retreated 12,000 years ago. There is a very high possibility that by the end of the century, the Earth is going to be a very different place as per the recent studies.
To steer the future away from a disaster, the authors of the article in Nature urge us to halt the human activities that are pushing earth towards the Tipping Point. In their words, “This will require reducing world population growth and per-capita resource use; rapidly increasing the proportion of the world’s energy budget that is supplied by sources other than fossil fuels while also becoming more efficient in using fossil fuels when they provide the only option; increasing the efficiency of existing means of food production and distribution instead of converting new areas or relying on wild species to feed people; and enhancing efforts to manage as reservoirs of biodiversity and ecosystem services, both in the terrestrial and marine realms, the parts of Earth’s surface that are not already dominated by humans. These are admittedly huge tasks, but are vital if the goal of science and society is to steer the biosphere towards conditions we desire, rather than those that are thrust upon us unwittingly.”
—————————————————————————————————————————————————-
Prof. Ashok Kumar Ghosh is Professor-in-Charge in the department of Environment and Water Management, A.N.College [Magadh University], Patna, India. He writes a column on environment and water resources in Bihar, exclusively for BiharDays every Monday.
—————————————————————————————————————————————————