“It is God’s planet – and he’s taking care of it. And I don’t believe that anything we do will raise or lower the temperature one point.”
Although the late Jerry Falwell had blind faith that our human folly would always be thwarted by a deity who is watching over us, evidence consistently seems to be to the contrary. Many times I’ve reported on this blog about breaking temperature records. Most of those I report are in North America since that’s closest to home for me, but such records are being broken all over the world. Surface temperatures are just one of the many ways to help prove that global warming is real.
Another important type of evidence is the melting of ice on our planet. We have a lot of ice in Greenland, Antarctica, and in glaciers all over the planet. But we also have a lot of ice in the Arctic. And unlike the other sources of ice listed above, Arctic ice is freely floating like a big ice cube. All of the other major sources of ice are land-based.
Over the last thirty-plus years since accurate measurements of Arctic ice have been recorded—primarily from satellite data—we’ve observed a steady decline in the size of the ice cap at our North Pole from year to year. So it only makes sense that we’d see another first with such Earth-shattering (literally!) temperature records being broken these days.
The National Snow and Ice Data Center (NSIDC) which is associated with the University of Colorado Boulder has been carefully following the extent of Arctic sea ice. Announced at a press conference on August 27, 2012, they announced the following (from their website):
“Arctic sea ice cover melted to its lowest extent in the satellite record yesterday, breaking the previous record low observed in 2007. Sea ice extent fell to 4.10 million square kilometers (1.58 million square miles) on August 26, 2012. This was 70,000 square kilometers (27,000 square miles) below the September 18, 2007 daily extent of 4.17 million square kilometers (1.61 million square miles).”
NSIDC Director Mark Serreze doesn’t blame global warming in so many words, but the inference is easy to make. According to him, “The previous record, set in 2007, occurred because of near perfect summer weather for melting ice. Apart from one big storm in early August, weather patterns this year were unremarkable. The ice is so thin and weak now, it doesn’t matter how the winds blow.”
Since there are a few more weeks in the melt season left, it’s likely the record will continue to break before this year is over. The final analysis for 2012 will come out in October, but it’s not looking good for the ice cap at the North Pole.
Unlike ice that melts from land sources such as Greenland, Antarctica, and glaciers, melting ice in the Arctic doesn’t contribute to rising sea levels. That’s because floating ice already displaces its mass, or it wouldn’t be floating. As it melts, that doesn’t change. (Archimedes helped to figure out this principle. As the story goes, once he came to some conclusions about density and buoyancy in his bathtub, he ran through the streets yelling “Eureka,” which means “I have found it!” Naked as a jaybird the whole time.)
So some people might not care that the Arctic ice is melting. Sad for the polar bears who depend on it for their survival, but hey, the economic benefits of a better sea passage from one side of the planet to the other is enough for any capitalist to start to seeing dollar signs.
But there are some real possible complications from this that many aren’t aware of. One I’m concerned about is that sea ice is largely fresh water compared to the salt water from which it was formed. Eliminating the salt as sea water freezes is a process known as brine rejection.
So as Arctic ice melts, it adds a lot of fresh water to the northern Atlantic. This changes the salinity—the salt content—of the ocean in that region. One concern about that is that it can change some naturally occurring ocean currents. Look at the Gulf Stream which carries heat from the Caribbean to northwestern Europe. It’s the reason you can find palm trees in Cornwall, England.
But a decrease in salinity can slow down the Gulf Stream. In fact, over the last sixty years, there is already evidence that the Gulf Stream has slowed down by about 20 percent. As the salinity continues to drop in that part of the Atlantic, this trend can continue, slowing the Gulf Stream even further or possibly even stopping it altogether. If this were to happen, less heat will be carried from the Caribbean to the United Kingdom and Scandinavia.
In other words, although many parts of the world will be breaking heat records repeatedly in the years to come, the melting Arctic ice cap may contribute to colder temperatures over much of an entire continent.
It’s all very complex, but I think the world would be a lot better off if we left it as it is rather than continue to alter it so dramatically simply because we can. And so quickly that noticeable changes are being observed within one lifetime.