Stop before the tipping point
The accelerated warming of the Arctic and Antarctica could trigger catastrophic climate changes, writes SHYAM SARAN
US President-elect Donald Trump has spoken about scrapping the United States’ international commitments to tackle global warming. This is worrying, not least because the US is one of the world’s biggest polluters. Trump’s disdain for global warming is way off the mark. The world has recently received dire warnings about the deteriorating health of our planet from two of its most fragile and critical ecosystems, the Arctic in the north and the Antarctica in the South. For India, with its extensive coastline, the implications are enormous.
The Arctic Ocean has experienced the warmest winter this year since temperature records began to be compiled. There has been an extraordinary 200 degrees deviation above what temperature levels should have been at this time of the year. Satellite images have also revealed that sea ice in the Arctic Ocean is at the lowest extent ever recorded. This may be dismissed as a “freak” phenomenon by climate change sceptics, but it comes as a culmination of a steady warming of the Arctic over the past half a century, resulting in a 75% loss of its ice cover.
In the Antarctica, there had been complacency because the loss of the thick ice cover over the southern continent had been minimal in recent years. The loss of some iceshelves located at the coast, had been made up by increased accumulation in other parts of the continent. However, just in the past few days, it has been reported that a massive iceshelf in the western part of the continent, known as Larsen C, may be about to detach itself from the thick mass of ice covering the continent, and float way into the ocean as a gigantic iceberg.
Larsen C is part of what was originally a very extensive ice-shelf, parts of which, Larsen A and Larsen B, have already disintegrated and floated away. Larsen A disappeared in 1995 and Larsen B in 2002. But Larsen C is by far the largest shelf in this part of the Antarctica, covering an area of over 50,000 sq. kms.
David Vaughan, Director of Science at the British Antarctic Survey, has said in a recent report: “Ice-loss from this part of West Antarctica is already making a significant contribution to global sea-level rise and is actually one of the largest uncertainties in global sea-level prediction.”
The Arctic and the Antarctic are different ecosystems but both are very fragile. The Arctic is an ocean, enclosed by land, constituted by territories belonging to the US, Canada, Russia, Greenland, Norway and Denmark. The Antarctica is an ice-covered land-mass of continental proportions, which is surrounded by deep ocean. The melting of ice, floating in the Arctic Ocean, will not add to net sealevel rise, but the mass of ice covering the Antarctica and Greenland (in the Arctic region), would add to the volume of water in the world’s oceans and lead to significant sealevel rise. If all the ice over the Antarctica and Greenland were to melt, there could be an increase in sea-level of several tens of feet, by 2100, inundating most of the major towns and cities located on the sea-coast around the world.
The Arctic Resilience Report recently warned that the accelerated warming of the Arctic could trigger “tipping points”, which in turn to lead to “catastrophic and uncontrollable climate changes.” It goes on to add the once these tipping points are reached, “the effects would become their own drivers of global warming, regardless of human attempt to reduce carbon emissions.”
This means that these anticipated changes may lead to much more severe global warming and climate change than what is already happening as a result of anthropogenic fac- tors such as burning of fossil fuels, cutting down of forests and environmental degradation. We are near the point where it would cease to matter whether we, as humanity, are successful in reducing and eventually eliminating greenhouse gas emissions. Much more powerful drivers of climate change are likely to take centre-stage instead.
But sea-level rise is not the only consequence to worry about due to the loss of the polar ice-caps. For example, the thick ice-cover over the Antarctica and over Greenland will release a huge amount of methane which lies trapped in the frozen bio-mass below the ice. The same is true of the permafrost that covers the northern zones of Arctic littoral. Methane is a much more powerful climate change-forcing agent than carbon dioxide (CO2) is, though it stays in the atmosphere for a shorter time than CO2. The release of methane will lead to a significant spike in global warming .
Another change relates to what is known as the albedo effect. The mass of white ice, both in the Arctic and the Antarctica, reflects back the rays of sun reducing the warming of temperatures. With its melting, much more of the heat from the sun will be absorbed by the oceans and the landmass, which will exacerbate global warming.
And finally, climatic conditions and oceanic wave movements in the polar regions have a significant effect on weather patterns around the world, including the monsoons in our subcontinent.
The threat to human survival is a clear and present danger. If we do not heed the warning signals which are coming to us from the very ends of the Earth, the time for any effective human intervention will soon be past.