“This was so extraordinary that at first I questioned the result: was this real or was it due to a data error?”
—Son Nghiem of NASA’s Jet Propulsion Laboratory
Satellites have been giving us useful information by providing images of our planet for over thirty years. One of the best ways we have to track changes in melting ice patterns is by imaging them with satellites. By watching what happens with the Arctic ice cap for example, we’ve been able to prove that it’s been getting smaller each summer to a significant degree in the span of one generation, one of the best sources of evidence that global warming is indeed happening.
Another large source of ice on our planet is the ice cover over Greenland. Unlike the Arctic ice cap which is a large floating ice cube floating in the Arctic sea, Greenland is a land mass, but it’s almost entirely covered in ice. Near the coasts the ice is very thin, but in the center the ice thickness can reach two miles.
Three independent satellites have been measuring the ice melting over Greenland, and analysis by NASA has verified that all of it’s surface ice is melting. Usually only about half of it melts, so this is a significant change above the average. By mid-July, the satellite data estimated that 97 percent of the ice sheet covering Greenland had thawed.
What’s even more concerning is how quickly the change occurred. On July 8 about 40 percent of the ice sheet had thawed near the surface. Only four days later, 97 percent had thawed. This occurred in the context of an unusually strong ridge of warm air, what was referred to as a “heat dome,” settling over the entire land mass. It moved into place July 8 and didn’t begin to dissipate until more than a week later.
Another reason this extent of ice melting isn’t surprising is because in the month of June, Greenland achieved a temperature of 76.6 degrees Fahrenheit. It would only make sense that record-breaking temperatures would be followed by record-breaking ice melts.
Summit Station, located in central Greenland is two miles above sea level. Signs of ice melting earlier this month have been observed there as well. This is far from normal or typical, for this part of Greenland. Ice core samples indicate that melting from snow at Summit occurs only about once every 150 years. It last happened in 1889.
For the deniers and skeptics out there, I’m sure they’ll point out this Summit melt is pretty much right on time then. But as Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data has pointed out, “if we continue to observe melting events like this in upcoming years, it will be worrisome.” Sadly, I believe that’s precisely what we’ll be seeing.
Most people who are concerned about global warming believe this excessive Greenland ice melt is another example of the type of evidence that should make us worried. If we don’t change our tune now with respect to greenhouse gas emissions that are contributing to this problem and soon, we’re doomed to our fates.