The worry about Thwaites is not just the estimated rise in sea-level but an unknown and sometimes incomprehensible cascade that its melting can unleash
Photo for representation: iStock Away from sight, away from mind — ancient wisdom has taught us. So, when a world-shattering event is about to unfold far away, should we worry or continue living life as we know it?
Thwaites glacier, symbolically known as the Doomsday Glacier, is sending confusing signs to the planet, as worst-case scenarios increasingly play out in real-time.
The glacier, one of the oldest in Antarctica’s west coast, rests on the ocean and in an event of its total collapse, its weight will simply add to that of the ocean, leading to unprecedented sea-level rise.
Estimates fluctuate and vary from one feet to several feet but most confirm that the glacier might break off quicker than we had estimated for.
The implications of its collapse is immense and is likely to rewrite both the history and geography of all living beings. Yet, minimal reportage and hardly an acknowledgement of the crisis unfolding in the icy pole means any mention of Thwaites is often met with disbelief and very often a shrug.
Read more: Thwaites ‘doomsday glacier’ can lose ice faster in coming years, coastal areas at risk: Study
What is Thwaites and why is it being described as the doomsday glacier of this decade?
First, it is giant, bigger than several states — as big as the island of Britain and about the size of Gujarat. At approximately 120 kilometres at its widest, it covers a basin of around 192,000 square kilometres.
When such a giant-sized glacier melts, the implications of its melting can have profound effects along the global shoreline.
Second, it is under unprecedented stress because of the anthropocene’s impact on Earth. For not only is it melting from above as a result of warming temperatures but is also impacted from warming ocean water steadily melting its underside.
As a result, the glacier, which is grounded to the seabed, might break off as it rapidly reaches its own tipping point. If that happens, much of the ice shelf will fall off into the ocean and add to the rising sea levels.
Glacial ice shelves tend to retreat and gain ice periodically. But around 2001, scientists figured that the grounding line of the glacier was retreating by a kilometre every year, causing immense breakoffs, a speed that has increased substantially in recent years.
With 4 per cent of the current sea-level rise already being attributed to Thwaites, it was only in the past few years that scientists found concrete evidence of warm water flowing below the glacier and melting it steadily from underneath.
How do we imagine its impacts, sitting so far — thousands of kilometres away — from ground zero. For one, imagine the glacier as a lone warrior against a mob. As the warrior holds off hordes of attackers, a time could come when the hordes overpower our warrior.
Thwaites is similar. If the outermost ice shelf collapses as predicted, it could rewrite its own tipping point with a likely chance that the entire glacier might find a way to the sea.
Particularly worrisome is the question of the grounding line, which is the point where land ice begins to float in the sea. At an average depth of 800-1,200 metres, the humongous amount of ice is witnessing a previously unknown retreat far below the ocean.
And as this line retreats, the shelf finds it increasingly difficult to stabilise. Again, imagine it as a question of balance. As the line retreats, the weight on top might cause the shelf to snap off and fall into the ocean. Simply put, we are in all sorts of trouble.
The worry about Thwaites is not just the estimated rise in sea-level but an unknown and sometimes incomprehensible cascade that its melting can unleash. While warm ocean currents nibble at the shelf, unhindered greenhouse emissions steadily increase surface temperatures.
Factors such as prevailing winds may push warm air further south and create a feedback loop leading to more melting. We have learnt in school that water expands when heated and in this crazy unravelling of the global climate system, warm seas in cutting the glacier’s underside are just following the laws of nature.
For a glacier that sits largely on the ocean floor, this deadly cocktail of warm waters and even warmer skies has inadvertently created what is today the greatest danger to life on earth as we know it. Already reeling with rising sea levels, another rapid rise of the seas could unleash chaos in our world as we know it. And if cities like Mumbai become uninhabitable, it does not augur well for a nation of more than a billion.
Science, by its inherent nature, tends to make conservative estimates, especially of doom and gloom.
However, these past few months have worried even the calmest minds, especially as B22a, a collapsed iceberg that had protected Thwaites for more than two decades, came unstuck and left the shelf at the mercy of gushing warm waters.
We may have already crossed not one but several tipping points when it comes to Thwaites but the obvious impact of such an unprecedented event will not leave anyone untouched. The attitude of the public towards this crisis possibly is: Worrying about the future of Thwaites will not undo the harm unleased upon the planetary system. So, why should we worry about this impending disaster?
It is now at our doorsteps and there is no way out but to confront our creation that is the climate crisis.
Views expressed are the author’s own and don’t necessarily reflect those of Down To Earth.
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