April 15, 2012, marks the 100th anniversary of the sinking of the Titanic. One of the most infamous – and saddest – cruise ships, we’re all familiar with its story.
In the dark, early hours of that 1912 morning, the Titanic – the largest ship of its time, crossing the Atlantic on its maiden voyage – slammed into an iceberg. The hole that was ripped into the Titanic’s hull led to one of the deadliest peacetime maritime disasters in history, and its sinking – and the more than 1500 deaths that resulted – surprised everyone, from the ship’s engineers to the general public. The Titanic was supposed to be unsinkable.
But an iceberg is destructive. They are extremely dense, and as a result, only a small portion of an iceberg is visible above sea level. The majority of the iceberg is hidden quietly underwater. Combine an iceberg’s great density, size and weight with a cruise ship moving nearly 30 knots in pursuit of a record-breaking crossing of the Atlantic and destructive became disastrous. So, with climate change upon us, we can be thankful that warmer sea temperatures will surely lead to fewer icebergs, and fewer potential shipping catastrophes that could result from iceberg collisions.
Wrong. As it turns out, climate change may be responsible for more icebergs in the ocean, not less.
“Climate change has the potential to create more icebergs,” says Frank Lowenstein, the Conservancy’s climate adaptation strategy lead. “It’s counterintuitive, but it makes a lot of sense. Climate change is speeding up the iceberg creation conveyor belt.”
Icebergs form by two mechanisms. In the North Atlantic almost all icebergs come from glaciers running down into the sea. Lowenstein says that warmer temperatures create extra melt water under glaciers, which acts as a lubricant and makes glaciers move more quickly to the ocean.
“So more icebergs can form because each glacier is bringing hundreds to thousands of extra tons of ice per year to the ocean.”
The other mechanism for iceberg formation is the gradual break up of ice shelves, which are already floating on the ocean, and are more common in the southern oceans. Lowenstein says that icebergs created from ice shelves can be much bigger.
“Those icebergs are humongous,” he says. “In 2010 an iceberg the size of Luxembourg that had broken off an ice shelf slammed into part of a glacier extending into the sea —snapping off a smaller iceberg the size of Rhode Island. Scientists are keeping an eye on other large icebergs: a Manhattan-sized chunk that’s presently off Newfoundland and another Manhattan-sized chunk that might break off Antarctica any day.
Should more icebergs in the ocean really be a cause for concern, however, when it comes to shipping lanes?
“I don’t think we need to worry about that,” says Lowenstein. “While there are likely more passenger liners in the ocean today than there were in the days of the Titanic, most of those are cruise ships in warmer waters. And running into an iceberg – even in northern oceans – isn’t very likely, thanks to new technologies like advanced radar systems.”
Still, the facts about climate change and its apparent affect on icebergs is unexpected, and shows how climate change continues to alter our world.
“What we do need to worry about is the effect on sea level rise. Even just a few inches can threaten coastal communities, erode shorelines and damage property.”
Lowenstein and others at the Conservancy are helping people prepare for this and other coastal hazards. But the answer doesn’t lie entirely with new, higher sea walls.
“Nature has its own defenses against rising seas and storm surges,” says Lowenstein. “Reefs, marshes, mangroves – when kept intact and healthy – can be very effective in buffering coastal communities. If we combine restoration with the use of cool new computer models that can show city planners where they might be the most vulnerable, we’ve taken a big step forward in keeping people who live near sea level safer.”
[Image: Titanic painting. Image source: cliff1066™/Flickr via a Creative Commons license. Image: Iceberg at LeConte Bay of Frederick Sound in Alaska. Image source: Bill Kamin. Image: Iceberg at LeConte Bay of Frederick Sound in Alaska. Image source: Bill Kamin]