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NASA Satellite Measurements Show Unprecedented Greenland Ice Sheet Melt
NASA reports that measurements taken from orbiting satellites indicate the Greenland ice sheet underwent melting over a larger area than they've seen in 30 years of observations. On July 8, the satellites found evidence that about 40% of the ice sheet's surface had melted. Observations just four days later showed 97% of the surface had melted.
"This extreme melt event coincided with an unusually strong ridge of warm air, or a heat dome, over Greenland. The ridge was one of a series that has dominated Greenland's weather since the end of May. 'Each successive ridge has been stronger than the previous one,' said Mote. This latest heat dome started to move over Greenland on July 8, and then parked itself over the ice sheet about three days later. By July 16, it had begun to dissipate. Even the area around Summit Station in central Greenland, which at 2 miles above sea level is near the highest point of the ice sheet, showed signs of melting. Such pronounced melting at Summit and across the ice sheet has not occurred since 1889, according to ice cores analyzed by Kaitlin Keegan at Dartmouth College in Hanover, N.H. A National Oceanic and Atmospheric Administration weather station at Summit confirmed air temperatures hovered above or within a degree of freezing for several hours July 11-12."
Photos also surfaced last week showing the Petermann Glacier in Greenland 'calving' — some very large chunks of it broke off and started to drift away.
Everyone is really good at rationalizing specific data points like "it's part of a 150 year trend". The problem is there's world wide evidence and not just glacier melts. There's a measurable trend going back to the industrial revolution when the CO2 release started. It accelerated in the 80s as growth in third world countries kicked in. It's everything from glacier melting to weird weather and from sea level rise to a severe drought in the US to the worst one in Australia in several thousand years. What I keep hearing is every time a piece of evidence shows up is "I can explain that". At what point do we accept that all the "I can explain thats" add up to we've got a problem? Long term what we are staring at isn't a hot planet but one that overreacts to a spike in CO2 causing a worse ice age than the last one. Rationalizing is a little like sticking your head in the sand. Each rationalization is another inch. Eventually your head hits China and the planet is still warming whether you like it or not.
Well in the UK I think we're probably prepared. This last 7 years or so we've seen everything from massive increases in rain through to winters that have been about 20C below historical averages.
In each case it's been because the jetstream has moved out of it's normal position. In March we had drought conditions across most of the country, since then we've had record historical rainfall ever recorded for the month of July and so forth. In 2010 we had a January/February that was so bad we hadn't seen one like it for about 40 years, by November that year it happened again, so from once in 40 years, to twice in a year. Last winter was unusually mild, we barely even went below 0C which was in stark contrast to the -20C we'd seen the two winters previous. For reference, normal winters would see lows of -6C to -8C where I live.
Perhaps it's a natural cycle, perhaps it's because of man's actions, but either way the jetstream running over the UK has been acting quite differently to what we're used to since at least 2005. It could well be that effects on the gulfstream are already causing what you suggest.
On the upside, whilst the weather we've had with a lack of jetstream in it's normal position is not pleasant, it's certainly not going to be the end of civilisation at least - we've managed to cope the last few years, but it seems it means we don't get proper summers anymore.