“We went to Antarctica to understand how changes to its vast ice sheet might affect the world.”
“Ice sheets flow downhill, seemingly in slow motion. Mountains funnel the ice into glaciers. And ice flowing from the land into the sea can form a floating ice shelf.”
“Glaciers in certain areas have been undercut by warmer ocean waters, and the flow of ice is getting faster and faster.”
“This is the first of three dispatches from a New York Times reporting trip to Antarctica.”
“The acceleration is making some scientists fear that Antarctica’s ice sheet may have entered the early stages of an unstoppable disintegration.”
“Because the collapse of vulnerable parts of the ice sheet could raise the sea level dramatically, the continued existence of the world’s great coastal cities — Miami, New York, London, Shanghai and many more — is tied to Antarctica’s fate.”
“A rapid disintegration of Antarctica might, in the worst case, cause the sea to rise so fast that tens of millions of coastal refugees would have to flee inland, potentially straining societies to the breaking point. Climate scientists used to regard that scenario as fit only for Hollywood disaster scripts. But these days, they cannot rule it out with any great confidence.”
“Recent computer forecasts suggest that if greenhouse gas emissions continue at a high level, parts of Antarctica could break up rapidly, causing the ocean to rise six feet or more by the end of this century. That is double the maximum increase that an international climate panel projected only four years ago.”
“Even as the threat from global warming comes into sharper focus, these scientists understand that political leaders — and cities already feeling the effects of a rising sea — need clearer forecasts about the consequences of emissions. That urgent need for insight has led scientists from Columbia to spend the past two Antarctic summers flying over the Ross Ice Shelf, a floating chunk of ice larger than California.”
“The Ross shelf helps to slow the flow of land ice from Antarctica into the ocean. Compared with other parts of Antarctica, the shelf seems stable now, but computer forecasts suggest that it might be vulnerable to rapid collapse in the next few decades.”
“Remote as Antarctica may seem, every person in the world who gets into a car, eats a steak or boards an airplane is contributing to the emissions that put the frozen continent at risk. If those emissions continue unchecked and the world is allowed to heat up enough, scientists have no doubt that large parts of Antarctica will melt into the sea.”
“But they do not know exactly what the trigger temperature might be, or whether the recent acceleration of the ice means that Earth has already reached it. The question confronting society, said Richard B. Alley, a climate scientist at Pennsylvania State University, is easier to ask than to answer:
“How hot is too hot?””