File:Greenland July 2019.png

@EricHolthaus

This week, 40 billion tons of ice will melt in Greenland as the European heat wave moves north -- enough to measurably raise global sea levels.

This single heat wave will create a permanent change in our oceans that will linger for millennia.

We are in a climate emergency.

@xavierfettweis

A heat wave is starting tomorrow over Greenland with Tmax reaching 25°C in tundra. The integrated anomaly of melt over the next 5 days (resp. over Summer 2019) will be 40Gt ~0.11mm (resp. ~0.65mm) sea level equivalent. Summer 2019 = what the models project for 2050 using RCP85.

Via London's Financial Times

A heatwave in Greenland is producing record highs across the ice sheet, including at East Grip, the second highest monitoring station. “If you start melting at the top of the ice sheet, we are going to lose [the] Greenland ice sheet long-term."

• https://www.ft.com/content/591395fe-b761-11e9-96bd-8e884d3ea203

At the summit of the Greenland ice cap the temperature rarely rises above zero degrees centigrade — the elevation is 3,200m and the ice below is more than a mile thick.

But last Friday (Aug 2, 2019), as the sun beat down, a small weather station laden with sensors captured something highly unusual: the temperature crept past zero and up to 3.6C — the highest since records began three decades ago. As temperatures rose across the massive ice sheet, which blankets an area five times the size of Germany, around 60 per cent of the surface started to melt, one of the largest ever recorded.

Scientists know of only three prior occasions in the past 800 years when there has been melting at the very top of the ice cap, which is kept chilled by the large volume of ice beneath. But this seems to be getting more frequent — it is now the second time this decade it has happened.

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