If you’re one of the 150 million people on the planet who lives three feet from the ocean, it might be time to move. That may as well be the advice from the panel of NASA scientists that spoke to reporters on Wednesday.
The panel had some dire news about the state of Earth’s rising seas, which have already risen eight centimeters (almost three inches) since 1992. That’s on top of the 20 centimeters of sea level rise (SLR) that has already occurred since the 1900s. Alone, a centimeter is a tiny thing, but this many in so little a geologic time is cause for major concern.
Back in 2013, the UN’s Intergovernmental Panel on Climate Change forecast one to three feet of sea level rise by the end of the century due to a combination of global warming and melting ice. New data now makes that a conservative estimate. One scientist, Steven Nerem of the University of Colorado, said the planet is “locked into at least three feet of sea level rise, and probably more.”
NASA attributes the rising seas to three factors of about equal importance: The expansion of warming ocean water, ice loss from the polar ice sheets and the melting of mountain glaciers.
Currently, the Earth is covered in enough ice to cause 216 feet of sea level rise if it all melted. That wouldn’t be enough to cover the planet, but it would wipe out every major coastal city, including Miami, New York, New Orleans, Tampa, Boston, Guangzhou, Mumbai, Nagoya, Osaka, Guayaquil, Ho Chi Minh City, Abidjan, Khulna, Palembang and Shenzen – among many, many others. However, it would take thousands of years for all the ice on the planet to melt, even with global warming.
But there’s still a lot of damage that can be done. One former NASA scientist, James Hansen, recently published a paper that predicts 10 feet of sea level rise could occur in just 50 years.
Even a more conservative estimate of six feet of sea level rise could be catastrophic. As Planet Expert Michael Mann recently explained on Real Time With Bill Maher, “If you think Hurricane Sandy, just that one foot of sea level rise that we’ve had already meant that there were 25 square miles of additional flooding along New York City [and the] New Jersey coast. It also meant that there was something like $7.5 billion more damage done by that storm. So if that’s what one foot does, imagine what six feet do. Six feet would mean you’re basically starting to abandon our coastal cities.”
Unfortunately, this state of affairs is now unavoidable. “It would take centuries to reverse the trend of ice retreat,” Eric Rignot, a glaciologist at UCI told Reuters.