Just last May, it was reported that the Ross Ice Shelf, which is ten times bigger than Manhattan, fell into the sea near Antarctica. Last March, the Larsen B ice shelf (the size of a small European country) in the Weddell Sea near Chile, also collapsed. Many scientists have blamed the collapses on rising global temperatures due to greenhouse gases.
Last February, a University of Colorado press release warned that melting glaciers could cause ocean levels to rise by as much as 20cm by the end of this century. To put that in context, a rise of 30 centimetres (1 foot) would push shorelines 30 meters (100 feet) inland. U.S. coastal cities like Houston are barely above sea level. A rise of one meter would inundate island nations like Seychelles (off the West Coast of Africa) and Kiribati (south-west of Hawaii) and would put half of Bangladesh underwater, displacing more than 100 million people.
Antarctica is covered by a sheet of ice averaging 2133 meters (7000 feet) thick. If all of it melted, ocean levels would rise by 61 meters (200 feet). Luckily for us, that shouldn’t happen anytime soon, as the “average” temperature in Antarctica is still well below freezing, at -37 degrees Celsius, even if some areas are starting to see temperatures above freezing.
I’ve seen another interpretation of the same data. Namely, that the current warming trend, as it causes the icecaps to melt, freshens the water in the oceans (icecaps are made of fresh water) and messes up the ocean currents that bring heat from the equators to the poles – potentially leading to a mini ice age.
Sounds counter-intuitive at first, but what I’ve read about it doesn’t seem “out there” – and ocean currents do perform a lot of the work of moving heat around the planet.
That’s a very fascinating article. And extremely frightening. They’re theorizing abrupt, radical climate change, that could occur at any time–maybe even this decade. The author makes a very astute prediction too. In the past, humans adapted to climate changes by migrating to more productive and hospitable regions. But today, the world’s population is huge, with barely any usable, unpopulated territory to absorb migrants, even if nations want to. Thus climate changes will be particularly severe for poor countries, whose populations are often unwelcome in richer countries. Billions of people world-wide could die within our lifetime, maybe within decades. It’s horrifying.