Climate skeptics simply can’t accept the idea that they might be wrong. So, they will grab onto anything and misinterpret it, even if their interpretation is obviously incorrect, to make their point. For years the Ice cover on the Arctic Ocean has been decreasing. Arctic summer months over the past ten years, including this year, have seen the greatest retreat of arctic ice on record in both extent and depth.
However, when Arctic Ice did not shrink as much this year as it did last year, climate skeptics jumped all over it. For example, the Mail Online almost gleefully headlined yesterday, “And now it’s global COOLING! Record Return in Ice Cap as it grows 60% in a year.” Their subheads state,
- Almost a million more square miles of ocean covered with ice than in 2012 [except the extent of ice decline was still among the top ten recorded]
- BBC reported in 2007 global warming would leave Arctic ice-free in summer by 2013 [but BBC is not a scientific body]
- Publication of UN climate change report suggesting global warming caused by humans pushed back to later this month [but that had nothing to do with the ice withdrawal]
Well, with condolences to the skeptics, the world isn’t getting cooler. So what did happen?
Last year the arctic sea ice reached its smallest extent on our records but the decline this year was not quite as large. NASA explains: This year’s melting season included a fast retreat of the sea ice during the first half of July. But low atmospheric pressures and clouds over the central Arctic kept temperatures up north cooler than average, slowing down the plunge.
The clouds are important because they reflect the light and heat from the Sun upward, away from the surface. That means two things: Less sunlight hits the ice directly, keeping it cooler, and, also, less hits the water, so that the water does not warm the ice from below. So, external meteorological events intervened. The important thing to remember is that this was still one of the ten largest declines in sea ice on record.
This image to the right, from the NASA National Snow and Ice Data
Sea Ice Extent for 2013 (solid line terminating on Sept. 10th
Center, confirms the extent to which 2012 is in line with declines in sea ice cover over the past decades: The solid, heavy line represents the average sea ice extent from 1981 to 2013. The blue area represents the (2 sigma) dispersal of annual data around the average. The dotted line on the bottom represents (the record low) data for 2012. Finally, the light solid line that stops at the bottom of the gray area (on September 10th) represents 2013 sea ice extent. It’s clear that 2013 is solidly in the pack, and toward the bottom, of low ice extent even if it is smaller than 2012. (For the curious reader, the original, which lets you display specific years, is here.)
Neither the decline in light reaching the sea ice in any one year nor the ocean water temperature due to cloud cover have anything to do with the warming (or cooling) process of the earth. Imagine if you accidentally put a soda in the freezer rather than the fridge and. when you took it out, it was frozen. You wouldn’t draw the conclusion that your refrigerator was colder. But that’s what these skeptics have done.
Global warming since 1880.
The image at left, from NASA/GISS, shows average annual surface temperature from 1880 to the present compared with the average temperature for 1951 to 1980 (in Centigrade) for the Northern and Southern hemispheres. The increase in temperatures over the period is both obvious and undeniable, and gives the clear lie to climate skeptics’ claims otherwise.
So, in spite of skeptics’ attempt to confuse people, reality continues: The earth is getting warmer and we need to do something about it. The future of our children, grandchildren, and great grandchildren depends on it.