Greenland mega meltdown places Earth on thin ice

On July 31, the largest island in the world, saw the biggest single-day melt since 2012 - about 12.5 billion tonnes of ice was lost to the Atlantic ocean by surface melt alone

Greenland is melting.

On July 31, the largest island in the world, most of which primarily falls in the Arctic Circle, saw the biggest single-day melt since 2012 - about 12.5 billion tonnes of ice were lost to the Atlantic Ocean by surface melt alone. This is enough to raise the sea level by 0.5 mm. 

The July ice sheet melt season ended with a net mass loss of 197 billion tonnes of ice, tweeted Ruth Mottram, a climate scientist at the Danish Meteorological Institute (DMI), Copenhagen. There is still one month for the 2019 melt season to end.

 

For those keeping track, this means the #Greenland #icesheet ends July with a net mass loss of 197 Gigatonnes since the 1st of the month. https://t.co/Qgwj6WtUzF

— Ruth Mottram (@ruth_mottram) August 1, 2019

DMI climate scientist Martin Stendel, in a tweet, said that the amount of ice that melted from the surface of the ice sheet on July 31 and August 1 would be enough to cover Florida with almost five inches of water. Imagine the entire state of Andhra Pradesh under five inches of water!

Greenland's ice sheet covers about 80 per cent of the country's surface and contains 10 per cent of the world's total freshwater reserves. To put it into perspective, it could cover a little more than the entire landmass of Rajasthan, Madhya Pradesh and Gujarat together, two times over. Some 56 per cent of this cover, which is nearly 2 miles thick in some places, saw detectable surface melting up to 1 mm on July 31 alone, according to Polar Portal.

The year 2012 was when Greenland last saw an intense melt event, which was much more than any year in the satellite record since 1979. In July 2012, for a few days, 97 per cent of the entire ice sheet indicated surface melting, which at one point, also touched 100 per cent, according to the US-based National Snow and Ice Data Center.

On the northwestern Greenland ice sheet, the 2019 melt till July 31 was 1.2 times that of the previous record melt in 2012, tweeted Jason Box, a glaciology professor at the Geological Survey of Denmark and Greenland.

Alarmingly, on July 31, melting was also recorded at Summit Camp, the highest point of the sheet located at around 10,551 feet above sea level, which rarely sees temperatures rise above freezing point.

Robert Rohde, lead scientist at Berkeley Earth, a California-based non-profit focused on temperature data, tweeted that on July 31, the Summit Camp had experienced melting for only the ninth time in 2000 years. The last time that happened was in 2012. The other years were -- 1889, 1192, 1094, 992, 758, 753, 244.

The melt, which seemed to have touched a record high on the last day of July 2019, spilled over into August with August 1 recording an 11-billion-tonne loss, according to the DMI.

In June this year, a heatwave had gripped Europe with temperatures soaring in countries like France, Germany, the Netherlands and others. Greenland seems to be experiencing its version of the heatwave, starting last week. Nuuk, the capital, reported temperatures in the high 50s Fahrenheit, about 10 degrees higher than average for this time of year. (55 Fahrenheit is the equivalent of roughly 13 degree Celsius), reported the New York Times.

Greenland's ice sheet 

Greenland's ice sheet is one of the only two ice sheets on the planet today. The other one covers Antarctica. 

 

Ice sheets are formed when the winter's snowfall does not completely melt during the summer. This snow accumulates over thousands of years into layers of thick ice mass, getting thicker and heavier with each new snow and ice layer every year. Greenland's ice sheet, at its edges, can be over 1,00,000 years old. 

 

So why is the melting of ice sheets concerning? 

The Antarctic and Greenland ice sheets together make up 99 per cent of freshwater ice on Earth. Here's an instance of what could happen if Greenland's ice sheet were to melt completely -- if the meltwater was to completely flow into the oceans, then the global sea level would rise by about seven metres (23 feet), our planet would rotate more slowly, with the length of the day becoming longer than it is today, by about two milliseconds, according to NASA.

 

NASA, quoting a study, also said that in the next 200 years, that melting of the Greenland ice sheet at the present rate could contribute 19 to 63 inches to global sea-level rise, posing a considerable threat to coastal towns and cities across the globe.  

 

Greenland also saw several wildfires in July, something that's unusual for a country with most of the landmass covered with ice. It was caused by unusually warm, dry weather conditions.

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