Climate Change Just Got a Whole Lot Worse
Climate change, for those of us who are paying attention, may be the single greatest existential threat out there. This week we learned that it could be worse than we have ever imagined. Scientists have been researching the Totten Glacier of East Antarctica, and their findings are grim:
The floating ice shelf of the Totten Glacier covers an area of 90 miles by 22 miles. It it is losing an amount of ice “equivalent to 100 times the volume of Sydney Harbour every year,” notes the Australian Antarctic Division. That’s alarming, because the glacier holds back a much more vast catchment of ice that, were its vulnerable parts to flow into the ocean, could produce a sea level rise of more than 11 feet — which is comparable to the impact from a loss of the West Antarctica ice sheet. And that’s “a conservative lower limit,” says lead study author Jamin Greenbaum, a PhD candidate at the University of Texas at Austin.
Think of the Totten Glacier as a cork in the bottle that is the ice sheet of East Antarctica. Remove that cork, which the rapid thinning of the glacier threatens to do, and we have a problem. Given that last year saw the discovery that the ice sheet of West Antarctica is, due to climate change, shrinking at a faster than expected rate, then the problem becomes very big indeed. The collapse of the West Antarctic ice sheet, thought to be one of the least stable ice sheets, could cause a sea level rise of 11 feet. Now we see that the East Antarctic sheet is potentially just as unstable, and will produce a comparable sea level rise.
And, lest you think that 11 or 15 or 22 feet of sea level rise is nothing to be overly concerned with, consider the impact of a rise of a mere 10 feet:
More than half of the area of 40 large cities (population over 50,000) is less than 10 feet above the high tide line, from Virginia Beach and Miami (the largest affected), down to Hoboken, N.J. (smallest). Twenty-seven of the cities are in Florida, where one-third of all current housing sits below the critical line — including 85 percent in Miami-Dade and Broward counties. Each of these counties is more threatened than any whole state outside of Florida – and each sits on bedrock filled with holes, rendering defense by seawalls or levees almost impossible.
And that is confining the analysis to the United States. Examined globally, the fruits of climate change driven sea level rise become even more unpleasant. Multiple island nations would simply cease to exist, even with a more modest increase in sea levels. Or consider the impact on the 100 million people of Bangladesh:
By mid-century, more than 3 million people stand to be directly affected by sea-level rise in the Ganges-Brahmaputra Delta. In a worst-case scenario, Bangladesh could lose nearly 25 percent of its 1989 land area by around 2100. In Bangladesh, the impact of sea-level rise may be worsened by other effects of global warming, such as variable precipitation, more frequent droughts and floods, and shrinking of the glaciers that supply water to the rivers of the delta. Reduced rainfall during the dry season, for example, can increase the salinity of rivers through encroaching seawater that moves upstream during periods of low flow.
It is, of course, tempting to look at all of these things as, since they are ever so far off in a distant future, less than meaningful. Few, if any, of us will be alive in at the turn of the next century. Who really cares if climate change has made a significant chunk of the world uninhabitable, if we won’t be alive to see it? Let’s just set aside, for the moment, the profoundly selfish nature of that take on climate change – there’s a bigger and blunter issue at play. What we are discovering, more and more, is that the effects of climate change are far more immediate than we would like to believe. Never mind the increasingly extreme weather events that have been occurring all over the world. Never mind the coming mega-drought in the American West. Never mind the specter of food riots, as small weather fluctuations lead to massive disruption of agriculture. If the melting of Antarctic ice sheets proceeds at the accelerating pace predicted by current studies and models, we’re in a lot more trouble than we thought, and a lot sooner.
When it comes to the Antarctic ice sheets, we may very well be past the point of no return. And given the glacial pace of global talks on climate change, and the meager changes that actually emerge from them, even if there were still something to be done, it is not terribly likely that humanity will manage to pull itself together enough to actually do it. A rise in sea levels, perhaps an extreme one, is a near-certain component of the future. Better invest in some water wings. |
