source : redflag.org.au
Another day, a new scientific study providing evidence of the terrifying scale of the global climate catastrophe. This time it is about global sea levels.
The study, titled ‘Unavoidable Future Increase in Melting of the West Antarctic Ice Shelves in the 21st Century’, was published in the journal Nature Climate change in October. It concludes that the West Antarctic Ice Sheet is already beyond saving, and that rapidly accelerated melting of the Antarctic ice shelves in the coming decades is now inevitable, even under the best warming scenarios.
Kaitlin Naughten – an ocean modeler at the British Antarctic Survey and lead researcher on the study – was blunt about its significance. The kind of sea level rise this melting will cause, she said, will mean that “some coastal communities will either have to build defenses or be abandoned.”
Scientists have debated whether Antarctica’s melting will be gradual and steady – progressing linearly, corresponding to increases in temperature – or whether there will be ‘tipping points’ that, once reached, will cause melting to accelerate dramatically. What this research suggests is that the more “optimistic” of these positions is wrong. We may already be witnessing an important tipping point being passed, due to the melting of the crucial ice shelves.
Ice shelves are masses of ice that lie on top of the ocean. The ice shelves around Antarctica play a crucial role in maintaining the stability of the enormous ice sheets that sit on top of the continent. The planks block the flow of the sheets down into the water. When the ice shelves melt, it opens the door for much faster ice melting as the shelves collapse under the relatively warmer temperatures of the ocean water.
Scientists have predicted that if the West Antarctic ice sheet were to melt completely – something this study suggests is now inevitable – it would cause a five meter rise in global sea levels.
This is just the latest bad news from Antarctica. Earlier this year, the area of sea ice around the continent reached a record low, with a net loss of 7.5 trillion tons of ice loss since 1997. As one researcher told the Guardian in March: “The rapid decline in sea ice over the past six years is quite remarkable, considering that ice cover has changed little in the 35 years before that.”
Also, the Antarctic ice caps are not the only ones that are melting. The biggest contributor to rising sea levels is the Greenland ice sheet, which scientists say can no longer be saved. Its loss is expected to add seven meters to global sea levels. Around the world, 28 trillion tons of ice were lost between 1997 and 2017.
Currently, more than 267 million people live in areas less than two meters above sea level. A 2019 study – “New elevation data triples estimates of global vulnerability to sea level rise and coastal flooding” published in Nature communication– found that: “In the case of Antarctic instability, a total of 300 (270–340) million people today live on land identified as vulnerable to annual flooding by mid-century, rising to as many as 480 (380 –630) ) million by 2100”.
Whatever the exact trajectory of warming from here, it is clear that capitalism-driven climate change will displace hundreds of millions of people in the coming decades.
Marx once wrote that the capitalist ruling class is “unfit to rule because it is incompetent to secure an existence for its slave within his slavery.” When he wrote this, by ‘existence’ he meant a decent living for workers. The current capitalist ruling class is unable to secure even the promise of a future above water for hundreds of millions of people.
source : redflag.org.au