Amid an ongoing heat wave, new data show the Greenland ice sheet is in the middle of its biggest melt season in recorded history. It’s the latest worrying signal climate change is accelerating far beyond the worst fears of even climate scientists. From a report: The record-setting heat wave that sweltered northern Europe last week has moved north over the critically vulnerable Greenland ice sheet, triggering temperatures this week that are as much as 25 to 30 degrees Fahrenheit warmer than normal. Weather models indicate Tuesday’s temperature may have surpassed 75 degrees Fahrenheit in some regions of Greenland, and a weather balloon launched near the capital Nuuk measured all-time record warmth just above the surface. That heat wave is still intensifying, and is expected to peak on Thursday with the biggest single-day melt ever recorded in Greenland. On August 1 alone, more than 12 billion tons of water will permanently melt away from the ice sheet and find its way down to the ocean, irreversibly raising sea levels globally.
[…] Even just a few decades ago, an event like this would have been unthinkable. Now, island-wide meltdown days like this are becoming increasingly routine. The ongoing melt event is the second time in seven years that virtually the entire ice sheet simultaneously experienced at least some melt. The last was in July 2012, where 97% of the ice sheet simultaneously melted. In the 1980s, wintertime snows in Greenland roughly balanced summertime melt from the ice sheet, and the conventional wisdom among scientists was that it might take thousands of years for the ice to completely melt under pressure from global warming. That’s all changed now. With a decade or two of hindsight, scientists now believe Greenland passed an important tipping point around 2003, and since then its melt rate has more than quadrupled.