How Long Until Sea Level Rise Prevents Inauguration From Happening in Washington DC?

By Ryan F. Mandelbaum on at

Donald Trump was excited about hosting the inauguration at the Lincoln Memorial. So excited, in fact, he bragged that he “didn’t know if it has been done before.” It has, of course — both of his predecessors had an event on the steps of the Lincoln Memorial. Trump is also excited about burning fossil fuels like coal and pumping greenhouse gas into the atmosphere.

With the inauguration today, we had to ask ourselves: how much warming will it take until sea levels rise high enough that we can’t host the inauguration in its current spot anymore?

The Lincoln Memorial Reflecting pool and the surrounding land sits around 10 feet above sea level, according to US Geological Survey maps. Scientists are confident that global mean sea level will rise at least 8 inches (0.2 meter) but no more than 6.6 feet (2.0 meters) by 2100, according to the National Oceanic and Atmospheric Administration-funded Climate Program Office, so there’s no need to worry for now. At the worst, spectators might need to walk through some river water on the way to the event.

Image: USGS

The fact that sea levels could rise less than a foot or more than six this century underscores just how difficult of a prediction this is. Mauri Pelto, a professor of environmental science at Nichols College in Massachusetts, says there’s a basic calculation one can use to determine sea level rise from ice melt. However, a lot of things contribute to the rate of ice melt, including the temperature of the sea and the air, and whether or not large icebergs start falling into the ocean. Calculating this stuff in the real world is really complicated.

Nonetheless, studies are attempting to do just that — figure out an approximate timescale of melting based on what we know about how ice melts. The two biggest ice sheets we’ve got are Greenland, which contains 680,000 cubic miles or 2.8 million cubic kilometres of ice according to Climate Central, and Antarctica, equal to 30 million cubic kilometres according to the National Snow and Ice Data Center.

Let’s ignore Antarctica for now. One paper, published in Nature Climate Change in 2012, calculated that, should unregulated carbon emissions push Greenland’s summertime temperatures 8 degrees warmer on average, the ice sheet would melt completely in around 2000 years. That leads to around a 6 meter or 20 foot rise in sea level, said Glenn Flierl, oceanographer at MIT, meaning we’d only need around half of Greenland to melt in order to swamp inauguration, which would take about a millennium.

But look, now I’m impatient. Let’s throw Antarctica into the mix. Another paper published last year in Nature estimated sea level rise due to Antarctica melting. The authors’ worst model, equipped non-stop greenhouse gas emissions and spiking temperatures, predicted that Antarctica alone could cause global mean sea levels could rise three metres, or ten feet, by sometime around 2150. Even the authors’ more conservative models estimated ten feet of mean sea level rise by 2300, though they caution that their models aren’t predictions and need more data.

All that is to say, the inauguration planners will probably need to find a new location by the next millennium, and as soon as the next 150 years. Drown the swamp! Drown the swamp!