Tuesday, May 23, 2017

Antarctica is Melting

The news is all Trump. His ill-considered words and constantly shifting explanations for impulsive actions dominate our public consciousness.

In the midst of all that Trump, it is hard to think clearly about the faraway future, beyond our lifetimes. When the future does intrude, it’s in the form of space ships and aliens, imaginary futures in faraway galaxies. But we need to think about the future here and now, because Antarctica is melting.

Actually, it’s more complicated than that. Great swaths of sea ice are breaking off from Antarctica, but that won’t cause the sea level to rise. That ice is already floating on the sea, so when it melts, the level doesn’t change. Try this yourself: fill a glass with water and ice, and watch what happens when the ice melts. The water does not overflow. Sea-level rise is caused when ice on land melts, adding to the volume of sea water. Right now, all over the world, glaciers are melting.

A group of American scientists flew over Antarctica last fall to get more accurate measurements of changes in the massive ice pack at the bottom of the world. If much of the sea ice melts, that could allow continental ice to loosen, flow into the ocean, and raise sea levels. That would be dangerous.

The global sea level has been rising an average of one-tenth of an inch every year. That doesn’t seem like much. That rise has been getting faster at about one-thirtieth of an inch per year, an even smaller number. Who cares about such tiny numbers? 

Over the long term, those numbers are scary. The oceans rose less than 3 inches from 1900 to 1950, 3.5 inches 1950-2000, and 2 inches in the last 15 years. If the acceleration continues, by 2050 the rise would be one inch every year, a foot per decade.

Three-quarters of the world’s largest cities are located on sea coasts. Between 100 million and 200 million people live in places that likely will be underwater or subject to frequent flooding by the year 2100. Some estimates put that number at 650 million, nearly 10% of the world’s population. Mathew Hauer of the University of Georgia estimated that 13 million Americans might be displaced by 2100, mostly in southeastern states.

Rising sea levels will do more damage than flooding coastal cities. Saltwater will contaminate our drinking water and interfere with farming.

There are many kinds of uncertainty in predicting sea-level rise. Not all geographic areas will experience the same rise. Some, like the East Coast of the US, will experience a much greater rise than the global average.

Can anything be done against the rising seas? After Hurricane Sandy, New York expanded its efforts to protect against the next flood. Based on careful geological analysis of the land, the city plans to reinforce beaches and breakwaters, build storm walls and levees, and protect sand dunes that act as natural barriers. That will cost money.

Another way to deal with unpleasant reality is to forbid it from happening, as the North Korean dictator Kim Jong Un did last year when he forbade his population to use sarcasm. After the Science Panel of the North Carolina Coastal Resources Commissioner said it was possible that the sea level could rise more than a yard over the next 100 years, the Republican-dominated legislature in 2012 forbade coastal community managers from considering scientific projections of sea level rise, when they think about roads, bridges, hospitals and other infrastructure. In 2015, the legislature accepted a new report that looked ahead only 30 years, thus with much less dire predictions.

State legislators in Virginia were surveyed about their knowledge of sea level rise. Republican legislators viewed scientists as less credible than Democrats did, and environmental groups not credible at all. Republicans estimated dangerous long-term effects of sea level rise as less likely, and thought that federal and state government should play a lesser role in dealing with them.

Donald Trump’s budget proposal embodies the Republican solution to rising seas: it would eliminate funding for climate research by NASA, the EPA, and the State Department. Mick Mulvaney of the Office of Management and Budget said about funding for climate research: “We're not spending money on that any more. We consider that to be a waste of your money.” That response is cheaper now, and the future is uncertain, so why worry?

Predictions, projections, estimates – these words display uncertainty. Nearly everything about climate change and its consequences contains uncertainty, especially when trying to forecast the future. That is why scientific models include ranges of possibility. One major question mark is how fast Antarctic ice is melting due to the warming of deep ocean currents far underneath the ice pack.

But this is certain – if we don’t get beyond the conservative refusal to think about the consequences of climate change, our grandchildren could face social and economic catastrophe. My daughter is pregnant. Her child might still be alive in 2100, living in a society trying to deal with an unprecedented disaster, the flooding of American coastal cities.

Political decisions, or their absence, will determine how ready America is for that future.

Steve Hochstadt
Jacksonville IL
Published in the Jacksonville Journal-Courier, May 23, 2017

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